computer function generator?

I want to build a simple computer based function generator and only spend about 10 dollars. Is it possiable, if so please lt me know about it.

Question by sci4me   |  last reply


can anyone provide me with some schematics for a function generator with only a 147.7 square wave AC signal? Answered

Can anyone provide me with some schematics for a function generator with only a 147.7 square wave AC signal? and im trying to make a it as small as possible

Question by tykora   |  last reply


stepper motor function as generator?

I want to make a stepper motor function as generator. Is it possible to do it if I don't want to hack the motor system? This is because, I cant change the principle of the motor itself. 

Question by SharifahA1   |  last reply


Schematic needed for square wave generator.

I need a schematic and the code for a square wave generator, with the following specs (although it is a bit specific) Repition Rate (external trigger, 20 Hz 200 Hz 2KHz 20 KHz 2 Mhz and 5 MHz) controlled by a rotory switch. a vernier (pot) controlling pulses per second.) a single shot button (N.O. push button) external trigger (BNC Connector) Delay (Rotary Switch)  .1, 1, 10, 100, 1k, and 10k microseconds Vernier (pot) for the delay a sync output (BNC Connector) with a toggle switch for polarity. double or single pulse on the output (toggle switch) polarity selection on the output (toggle switch) gate on off (BNC connector and toggle switch) 10db step (on or off toggle) 50 ohm load on or off (toggle switch) rise and fall time (pot) Any help would be greatly appreciated, as this is a bit specific. I only need a schematic, and everything else i can take care of. Once again, Thanks for the help.

Question by mchp82   |  last reply


Sine Generator

I am looking to create sonoluminescence at home and one of the main things that I need is a 25 KHz sign generator!  I have been looking everywhere and I can't find one or how to build one.  I any of you can help please do.  Thanks in advanced Here is a link to what I am going off of http://www.macgeisler.de/nld/sbsl-howto.html

Topic by Cody Heiser   |  last reply


what is the use of a petrol in a generator?

The major function of petrol and the passage of the petrol in a generator

Question by jabal23   |  last reply


How to make a functional sonic screwdriver?

What sort of technology could one fit into something the size of The doctor's screwdriver? I was thinking about maybe a universal remote, an rf/if one maybe a small laser (100-500 mW) maybe a function generator with an antenna and a frequency generator with a speaker or something, just to make it be sonic. Making it clear, not just a prop but with some interesting functions. Any suggestions? Also if possible anything that can be salvaged from old equipment and electronics that can be used please say it.

Question by amelius   |  last reply


5th Generation Ipod repairs

Ok guys I wasn't quite sure whether to post this in the general forums or right here. I figured I would get more help here so here goes. My good friend washed her Ipod video 5th generation so she didn't want it and gave it to me.The only problem that is visible on this Ipod is a broken screen. But the problem that I'm concerned with is not the screen but the hard drive because I don't know if it's still functioning or not. Whenever I plug in the usb transfer cable, and hold the ipod up to my ear I can hear a tiny squeaking sound as if the hard drive is still spinning. I don't really know where to go from here guys so if anyone could offer advice on what to do next to figure out if the hard drive still works or not it would be greatly appreciated. Thanks

Topic by hacker-mattg   |  last reply


how do I make a wireless power supply for my bike lights? Answered

If I created a generator for my bike (using pedal power) how can i wirelessly transfer this to bike lights or ipod charger ect...? I know induction is a way of wirelessly transmitting power and there are several instructables on this though I haven't seen a fully functional one and they're all worded in a very technical language that I don't understand.

Question by cdubnbird   |  last reply


MPLAB and PIC16F628A, basic EEPROM functions wont work

Hello all Ive got a query about the simulator in MPLAB.  I'm using a PIC16F628A-IP and Ive written a couple of subs to run the EEPROM functions, but when I try and run the program in the simulator and observe the registers, I'm noticing that EECON1 is not accepting bit changes, and when reading from the EEPROM, i get as far as getting the correct value into W register (MOVFW EEDATA), then the next step, simply a RETURN command, for no reason wipes the W register back to 0 and hence the routine always returns a 0 Can somebody have a look and see whats going wrong, this is one of the easiest routines to write as there are so many examples on the web, Ive even used code straight from Microchip's Code Library and that didnt work either, its driving me MAD!!! All I am trying to do with the following code is simply read the EEPROM contents of address 05, display the returned contents to PORTB, wait a second, then increment the contents by 1 and resave into the EEPROM at address 05, so by rights on power up I should see FF then 00 then 01 then 02, etc, incrementing every second, on PORTB....I'm a bit of a stickler for custom keywords so sorry if its a bit confusing, makes perfect sense to me of course! ;  GENERIC PROGRAMMING HEADER  LIST P=16F628A   ; DETERMINE CORE TYPE  INCLUDE "P16F628A.INC" ; INCLUDE DEFAULT ASSEMBLY FILE FOR THIS CORE  ORG 00H     ; START PROGRAM AT LINE 0  RADIX HEX    ; ASSUME HEX UNLESS SPECIFIED  ERRORLEVEL -302  ; NO BANK WARNINGS DURING ASSEMBLY   ;  SET BURN CONIFGURATION FOR NO WDT AND INTERNAL OSC AT 4MHZ  __CONFIG _CP_OFF & _WDT_OFF & _PWRTE_ON & _BODEN_OFF &_INTRC_OSC_NOCLKOUT & _MCLRE_OFF & _LVP_OFF ;  CONSTANTS AND VARIABLES OPT  EQU 81H  ; OPTION REGISTER NN  EQU 02AH ; GENERAL N REGISTER FOR COUNTING DELAYS XX  EQU 02BH ; GENERAL X REGISTER FOR COUNTING DELAYS YY  EQU 02CH ; GENERAL Y REGISTER FOR COUNTING DELAYS TEMP EQU 02DH ; GENERAL TEMPORARY FOLDER 1 TMP  EQU 02EH ; GENERAL TEMPORARY FOLDER 2 FLAGS EQU 020H ; MISCELLANEOUS PROGRAM SPECIFIC FLAGS N  EQU 021H X  EQU 022H ; GENERAL TEMP STORES Y  EQU 023H ;  CUSTOM INSTRUCTIONS #DEFINE   BANK0     BCF       STATUS,RP0          ; Sel Bank 0 #DEFINE   BANK1     BSF       STATUS,RP0          ; Sel Bank 1 #DEFINE   READNVM CALL READ #DEFINE   WRITENVM CALL WRITE #DEFINE   W10MS  CALL DELAY #DEFINE   W1S  CALL DELAY1S ;----------------------------------------------------------------- ;  INITIALISE MICRO ;----------------------------------------------------------------- INIT   BANK1   CLRF  TRISB ; PORT B DEFINED ALL OUTPUTS   MOVLW 0FFH   MOVWF TRISA ; PORT A ALL INPUTS   BANK0 ;  SET TO MIMIC 16F84 BY TURNING OFF COMPARATOR   MOVLW 07H   MOVWF CMCON ;  PURGE GENERAL RAM FILES   CLRF NN   CLRF XX   CLRF YY   CLRF TEMP    CLRF TMP    CLRF FLAGS   CLRF N   CLRF X   CLRF Y   CLRF PORTA   CLRF PORTB   CLRF OPT   CLRF INTCON   ;------------------------------------------------------------------- ;  MAIN PROGRAM ;------------------------------------------------------------------- MAIN; ORIGIN   MOVLW 05   READNVM   MOVWF PORTB   W1S   MOVLW 05   MOVWF EEADR   MOVF PORTB,W   INCF W,1   MOVWF EEDATA   WRITENVM   GOTO  MAIN ;--------------------------------------------------------------------------- ;  END OF MAIN PROGRAM BODY ;---------------------------------------------------------------------------   GOTO FINISH  ; PROGRAM LOOP FALLOUT ;--------------------------------------------------------------------------- ;  SUBROUTINES ;--------------------------------------------------------------------------- ; LIST OF AVAILABLE SUBS: ; DELAY  = 10mS DELAY ; DELAY1S  = 1 sec DELAY ; WRITE  = WRITE TO EEPROM, MUST BE LOADED WITH EEDATA AND EEADR B4 ENTRY ; READ  = READ FROM EEPROM ADDRESS HELD IN W BEFORE ENTRY, RETURN RESULT IN W ;  10mS DELAY DELAY       MOVLW 0AH   MOVWF XX OUTER   MOVLW 0C7H   MOVWF YY INNER   NOP         NOP         DECFSZ  YY,1         GOTO    INNER                 DECFSZ  XX,1         GOTO    OUTER   NOP   NOP   NOP   NOP   NOP   NOP   NOP         RETURN DELAY1S   ; 100x10mS DELAYS   MOVLW  064H   MOVWF NN D1L  W10MS   DECFSZ NN,1   GOTO D1L    RETURN   WRITE       BANK1         CLRF EECON1                        BSF EECON1,WREN            ; enable write   W10MS   W10MS   BCF INTCON,GIE         MOVLW H'55'                ; magic sequence         MOVWF EECON2                       MOVLW H'AA'                          MOVWF EECON2                       BSF EECON1,WR   W10MS   W10MS             eeloop BTFSC EECON1,WR            ; wait for WR to go low         GOTO eeloop                ; not yet         BCF EECON1,WREN                    BCF INTCON,GIE           ; clear the interrupt flag         BANK0   W10MS   W10MS         RETURN READ BCF EECON1,WREN   MOVWF EEADR                ; set up eeprom address from W         BANK1   BSF EECON1,RD              ; set the read bit         BANK0   MOVFW EEDATA              ; return value in W         RETURN   ;  PROGRAM ENDS FINISH   END Note, this will probably make more sense if its copied and pasted into an ASM in MPLAB, as the tab stops and comments become more apparent THanks for looking  

Topic by whitebakecase   |  last reply


Are the parts in 5th generation iPods interchangeable in spite of differing harddrive sizes?

I have two 5th generation IPods. On the 30gb, the battery needs replaced, and on the 80gb the screen needs replaced along with the motherboard. Is it possible to simply combine the working innards of both iPods into one functioning, 80gb iPod?

Question by dnflowers   |  last reply


Arduino help - how to use dtostrf () function

Hey everyone, I am measuring voltage over 2 analog inputs on my arduino uno.  I want to be able to do this wirelessly, so I got a microSD shield. I am trying to get it to send the data over to the SD after measuring it and putting it into voltage, but I can't figure out how to use the dtostrf function properly. I am really new to arduino and programming in general, and this project is time sensitive, so don't give me any answers like go read a book. How do I properly use it in this context? Thanks Here is the void loop part of my most recent failed attempt: void loop() {   //string for assembling the data to log: String dataString = "";   //read 6 sensors and append to string:   for (int analogPin = A0; analogPin < A2; analogPin++)   {     int sensor = analogRead(analogPin);     float sensorValue = ((float)(sensor) *(5.0/1023.0));    dtostrf(sensorValue, A0, A1);     if (analogPin < A2) {       dataString += " ";           }   }     /*open file-only one can be open at once     close this one before opening another*/     File dataFile = SD.open("datalog.txt", FILE_WRITE);       if (dataFile) {     dataFile.println(dataString);     dataFile.close();     //print to serial monitor as well.     Serial.println(dataString);   }   //if file doesn't open, print pop up error   else {     Serial.println("error opening datalog.txt");   } delay(300000); }

Topic by lmboyer   |  last reply


Injecting signal into a cable

For a part of a project on Power theft detection on a cable, i needed a way to inject a signal on a cable. Can anyone please suggest a method inject the signal. The signal is a pulse generated by a function generator.

Topic by killswitch123   |  last reply


Is it possible to step up the voltage of square wave ac coming out of a function generator from 5ppv around 10ppv? Answered

I'm trying to use a square wave function generator for the purposes of inductively charging a cell phone. Also, would magnetic shielding be necessary for this application or is the magnetic field weak enough to not interfere with the phone?

Question by phillystealth   |  last reply


HELP - Energy production idea needing some tips and tricks

Good day to allI'm not quite sure this is the right forum for this so bear with me if it's not :PI'm looking for some info and ideas regarding a project that has been brewing in my head, but since i am no more than an initiate in all this mech and tech stuff i figured this would be a good place to find some help.I'm trying to create a low budget way to feed a 12v battery without having to use solar, hydric or wind power. Basically i want not to be dependant on atmosferic conditions so i wanted to use human generated mechanical thrust to generate enough electricity for some basic stuff. This project is to be put inside a yurt in the middle of a forest so one can have a few hours of light and maybe even enough power to charge a small laptop or a cell phone.This is my idea:I thought of using one of these old sewing tables connected to a small motor(instead of a sewing machine) in order to generate electricity which would then be stored in a battery , more or less the same process by wich a dynamo powers a bike's lamp but in a different scale.But to achieve this i still have many questions and doubts that i'm going to share with you all in the hope that some bright ideas might help me bring the project to life.-Question 1 I'm thinking the system should be composed of: Sewing table (Mechanical thrust) Motor (Generator) Some sort of electric rectifier (same function as the ones used with solar systems) 12v Battery Is this looking logical or have i missed something??-Question 2.a What kind of motor is suitable for energy production? I've been reading about this and if i understood right there are 2 kinds of motors. One kind that uses pre generated electric current to magnetize a coil wich in turn produces motion and another kind wich is built with permanent magnets. This later one would be the one i'm looking for, am i right?? Or could it be that not all PM motors can be used to produce energy from motion??-Question 2.b What kind of apliances use this kind of motors? I've just openned a broken vacuum cleaner to check it's motor but it has 2 sets of coils and no magnets, so i'm guessing it is the kind that needs electricity to magnetize one of the coils... LOW BUDGET is a key factor of this project and recycling the motor would be perfect.-Question 3 What about the rectifier... I'm guessing i should have some kind of apparatus which would normalize the energy that is going into the battery and also that prevents me from emptying the battery in order to preserve it. I'm wondering if a regular box like the ones used on solar systems would do the trick...-Question 4 I realized that these table's wheels can spin in both directions, and i'm guessing that this will have some kind of influence on the polarity of the energy produced by the engine and that this might pose some problems. Is this true?? And in case it is, any chance that the rectifier takes care of this or do i need to find a way to force the wheel to spin in only one direction?I still have many other questions but these are probably the bigger ones.I hope someone might help me with all this.Thank you very much in advance.

Topic by dameluz   |  last reply


Gas furnace plugged into 120V solar/wind generated power bypasses the thermostat control and starts immediately. Why?

The sine wave generated by my 12v to 120v inverter scopes even better than the grid current.  All other appliances function normally on off-grid power.

Question by Twicewidowed   |  last reply


Digital Photoframe to LCD monitor / general tech question

I have this digital photoframe lying around. It has no input other then a SD card slot. When I look at the datasheet (somehow I can't upload the file, but you can find the datasheet here) I see the different functions of the screen connector pins (page 5), including: Blue Analog Video Signal Green Analog Video Signal Red Analog Video Signal I was wondering, is that somehow related to the RGB from a VGA signal, since VGA is also an analog signal? Would it be possible to connect the RGB from a VGA cable to these pins to use the photoframe as a (lowres and slow) external monitor? I guess it's not as straight forward as just attaching 3 wires is it?

Topic by javl   |  last reply


Is it possible to generate and display waves using the same arduino due board in real time???

OK!So I intend to design an Arduino Waveform Generator interfaced with the Nokia LCD 5110 with Keypad support.I have successfully incorporated the Keypad interfacing part but have stumbled upon waveform display on the Lcd. My program generates waves on DAC1 which i then give as input on the Analog(A0) pin of Arduino Due just like an oscilloscope takes an input externally.i tried merging it with another program which takes an analog input from the function generator and displays it on the LCD.More importantly,the programs work fine individually! So,is it possible to do this on the same board????Where could i possible be going wrong? Reply asap !!

Question by Lakshya1503   |  last reply


Sort instructables by votes or views, contest participants or in general. And detailed stats too?

Hello.No doubt we need this function, to see what is trending and what is requested and what is popular. Can we?Also. Stats are great, but giving me "bare" domain without actual referring page is pretty useless, don't you think so? like say I have 100 visits from "t.co", which is twitter domain, but usefulness of that data is close to 0, if I don't know the actual tweet(s) which caused traffic to here, right?

Question by AceSound   |  last reply


how to repair a chipped solar cell? is super glue ok to use to repair a broken cell?

Will super glue hold this piece back on ?And if the chipped part of the cell is put back in place will the cell work and function as a whole as if it were never broken and generating power = to a new unbroken cell?

Question by snakdimen   |  last reply


Electronic Toolkit

I do some work with the FIRST Robotics kids and it is amazing to see what they are doing.  Big problem though seems to be a general lack of electrical test equipment.  They don't really have the money to buy oscilloscopes, function generators, CAN and I2C analyzers.   So I got one of the M3 Discovery boards from STmicro and it is really cool.  It has four 5MS A/Ds on it plus a whole host of other features(CAN, I2C, Serial etc.). http://www.st.com/web/en/catalog/tools/PF254044 So it got me thinking. Why couldn't we turn one of these chips into an "All-In-One" electrical toolkit and keep it cheap($50-$60, BOM ~$20).  It would be fairly easy to turnkey. I threw together some simple specs, what do people think. 1) Will supply general use drivers so a user can use the app or write their own. 2) Oscilloscope   a. Two Channel     i. 2MHZ of Analog Bandwidth per channel     ii. 10MS/s per channel     iii. Trigger on rising edge, falling edge, on-command, run-stop actions     iv. Datalogging for extended time periods at up to 10hz per channel (data stored directly to console),  maybe higher rate will  just have to see 3) Serial – 2 Ports   a. Multi selectable protocol w/slew control     i. RS232, RS422, RS485 4) CANBus – 1 port 5) I2C – 1 port 6) SPI  - 1 port 7) 8 Discrete User Selectable 8) Function Generator   a. Two Channel      i. 1MS/s small signal change      ii. 250kS/s full range change      iii. 0-3.3VDC buffered output  9) PWM - 4 Channels

Topic by ase4542   |  last reply


Can I send Parallel Port outputs/Record Parallel Port inputs with Batch files?

Is there any way that I can do this? If possible, can you please specify how I would accomplish this, and any other things you may know about Parallel Ports, Batch Files, Maximum Input Voltages On A Parallel Port, and the functions of the leads on the Parallel Port socket. If this isn't possible, I would be grateful if you were to point me in the right direction(Ex: other languages and programs that support output/input, info about coding, etc.). Thank You in advance!  I was planning on developing a simple blinking Led or Tone generator, and the only feasible way of doing this may be a Batch file (feasible because Batch files are the only things I can create on my own without trouble. :( ). I am also going to attempt to record the codes on a remote using an IR sensor so I can develop "An ultimate computer-based remote control".

Question by =PhysicsGuy=   |  last reply


Logic circuit to generate and convert 3 bits parallel binary code into series for subsequent transmission ? Answered

A project I am working on has 6 water sensors placed at different altitudes inside a tank.I've developed a circuit to assign 3 bit binary codes to each of the sensor and then transmit it wirelessly.I've attached the truth table and the binary functions that yield the desired output, as a picture.Please refer to it and check if it looks alright to you.Keep in mind that the sensors output '0' (ground) when idle and '1' (Positive) when active.  Also, the sensors are so placed that sensor 2 won't get activated unless sensor 1 is activated ,sensor 3 unless sensor 2 is activated and so on..I.e,when the sixth (last) sensor is activated ,all the other sensors would be active too.So,the truth table contains just the possible combinations. A,B,C,D,E and F are the sensors(bottom to top) X,Y and Z will be fed into a binary encoder ic,whose output will be transmitted. Surfing the web,I realised that logical high and low can also be set using pull up and pull down resistors .I would appreciate it if someone could enlighten me on how this is done.(Explaining with reference to my circuit will be the best way)

Question by Adarsh_tronix   |  last reply


How do I make the dc only portion of a strobe light? I already have a trigger.

How do I go about making a simple 120vac to 300vdc power supply? I am making a strobe light and gave a trigger set up but I need a way of getting the darn thing to light. PLEASE HELP. Is there any way to use my function generator to replace the trigger?

Question by professorred   |  last reply


Raspberry Pi 3 Vs UDOO Neo

Which is a better development board, in terms of automation, robotic and server function?  I plan to build a mobile-operated generic wireless controller that gathered data and also programmable in terms of control. I already drop by to other forums and still undecided. I don't consider a development board that so powerful. What I consider is the practicality, suitability, and compatibility. I appreciate your response and I want to know your ideas about this! Thanks and God bless!

Topic by ephtermulo 


what can I do with some old iomega zip drives?

I got 3 or 4 of these lying around, gotta be some cool servos or something in them. Might be parallel or scsi connectors on back. Even have a few disks if I needed them, though they've been run thru the magnet so data retention would be doubtable.Would there be functional replacements in them for parts in this project? https://www.instructables.com/id/Hard-Drive-Parts-Generator-and-Theory-Tester/

Question by flashj   |  last reply


How do you crash a computer?

Using any common household technology, how can one create a compact device that can crash a computer without actually doing anything to software. hardware crash. idk magnetic fields, large electric currents? something hand-held preferably. Safe to hold not safe to a computer within a few inches.  Update: You are all right, a reversible device is best, but not completely, as in wipes all memory but the computer is not actually destroyed so can still function with a new OS installed

Question by amelius   |  last reply


Best way to accurately measure capacitance w/ osciloscope?

I am sure there are many ways to measure capacitance w/ an oscilloscope, and one of the annoying things is that some capacitors have different capacitance at different voltages and test frequencies. My original idea was to use the RC time constant and a known resistor, but I think this is probably the least accurate way to do this. Would using a sine wave function generator and figuring out capacitive reactance (and capacitance) be the better method? OR what about measuring resonant frequency of a LC tank circuit? Or some other method I have not mentioned? What's the best?

Question by -max-   |  last reply


Peltier Cells?

In the current make magazine issue #15 There is a project called the Seebeck Generator. I was wondering about the use of Peltier Cells. Can someone elaborate as to how they function? I mean can you get them in different sizes? Would different sizes effect the power output? If I took like 50 of them and somehow combined them could I get a higher yield? What if you used it in combination with something like Hydrogen? Ideally Hydrogen burns hot and if I had a large version of the Peltier Cell Could I use it to get a real power output? Possibly enough to power an electronic motor? Just some random thoughts the magazine sparked. Thanks, Jester

Topic by Jester_boy2   |  last reply


Using Theremin to Modulate Pitch of an Input for Use in Sonic Screwdriver?

I'm not real familiar to the in depth functioning of the Theremin, but I think I have the general gist of how it works. Specifically, I was wondering If it was possible to use a Theremin to change the pitch of a sonic screwdriver. One of my qualms with sonic screwdriver replicas is that they lack the changing pitch of the screwdriver in the show (Doctor Who, to the uninitiated). After reading about Theremins, I wondered if one could be built into the case of a sonic screwdriver (DIY with metal case) allowing the pitch of the sound to be altered in relation to its proximity to the users hand(s) and the environment. Has anyone ever heard of something like this being done?

Question by danielemur   |  last reply


FatFs Library

Hello everyone, I have recently been working on porting the FatFs Generic FAT File System library to an Atmega328p for use with a project I'm working on and I'm really having some issues with it.  I've tried a couple of different tutorials and walkthroughs and in the end I either get odd errors that seems will be an incredible hassle to correct, or my program compiles but the actual program won't work correctly (none of the open, write, etc functions actually work) I am writing this in Atmel Studio 6 (AVR Studio) If anyone can please help me out, or if you have ported this for the atmel mega series before and can provide your files that would be awesome Thank you

Topic by BooRan 


Simple wireless remote switch

Hi all, Long time fan off the site. Just wanting to verify this a concept before buying and building. current situation, looking for a wireless switch solution for a X-ray generator: Machine has a 2 stage switch 1st depress is prep 2nd depress fire. switch is wired with standard telephone cable red and black common. yellow prep  green fire I think the product linked(sorry if not allowed) will do the trick? http://www.ebay.co.uk/itm/12V-2-Channel-Wireless-RF-Remote-Control-Controller-Switch-Receiver-Transmitter-/152308878478?hash=item2376510c8e:g:a~wAAOSwZVlXpZ3X It has configuration for momentary connection so function would have to be hold a button then when ready hold b button Any issues with this?

Topic by TerryJ31   |  last reply


Arduino Uno Synth project - Audio output questions

Hi! I am developing a synth/sampler project based on the Arduino Uno r3. This is my first electronics project ever and because of that reason I have some questions which I can't find a definite answer for on internet. The synth has two function. It has a tone generator using the ToneAC library. With code I have mimicked LFO and VCO functions, using potmeters I can adjust the frequency and LFO speed realtime. The other function is that I can trigger samples stored on a SD card using the TMRpcm library. The device will be used in nightclubs on high end soundsystems and PA. I am afraid I will damage the equipment with my device because I do not send a pure audio (AC?) signal. Currently the flow is like this: PWM output (pin 9, 10) -> voltage divider to 2.5v -> RC Low Pass Filter 15Khz -> LM386 amp with volume control -> mono jack output -> mixing desk -> amplifier -> speakers (the TMRpcm and ToneAC library share the same pin (9), I have fixed this by disabling the TMRpcm when the ToneAC is playing and vice versa. The mono jack is wired as follow. pin 9 goes to plus side of mono jack output, pin 10 to negative side. The TMRpcm pin 9 also needs to go to plus side of mono jack output, and mono jack negative needs to go to ground. Because I disable the ToneAC at that time I consider port 10 grounded because it not generating any sound so there is no signal/voltage running out of it, aka the IO pin is set to LOW) I am hoping that using the voltage divider I am within range of the Audio Line levels of a default mixers Line-IN (like Pioneer, Behringer, etc). The RC Low Pass Filter is used to filter of inaudible frequencies and clean up the sound a bit, the LM386 audio amp is used to amplify the signal and (hopefully) make it a real audio signal. The lowest frequency you can play with the synth is 100hz and the highest frequency is 3100hz. Because I lack a lot of knowledge in this field and because I do not own a oscilloscoop I can't say for sure if my output signal is harmful for the equipment and was hoping to get some guidance on my project on this forum.

Topic by erik404 


How to make a button or sensor select an audio file from a memory device?

I would like to know about any instructables (or help in general) on making an arrengement that would make use of a button or motion sensor to select a music or audio file from a memory storage device (like an mp3 or a Compact Disc player) and let me play it on a set of speakers. Anything on that line would be appreciatted including (but not limited to) peripherals that can be bought pre-assembled with this functionality. I have already checked this instructables, but were to no avail (not what I was looking for): https://www.instructables.com/id/How-to-Connect-a-Sensor-with-Audio-Input-and-Outpu/ https://www.instructables.com/id/How-to-Connect-a-Push-Button-with-Audio-Input-and-/ This resembles what I am looking for (but I prefer longer lasting ones): http://www.radioshack.com/graphics/uc/rsk/Support/ProductManuals/2761323A_PM_EN.pdf Hope you help! Thanks in advance, Cab

Question by Cabzx   |  last reply


hi!Mood is still naked!

hi!Mood is a wi-fi device which generates led patterns and plays music in sync with your mood. It plays the tracks which best fit how you feel directly from stereomood.com, associating to each song the coolest and most appropriate RGB led pattern matching your mood. You can interact with hi!Mood through a mobile app interface so that hi!Mood focuses only on what it can do best: playing music and generating colored light patterns matching your mood! hi!Mood is being developed by A-Pole, a mobile application development studio which is creating innovative mobile apps to know more about the world around you and interact simply with everyday electronic objects. A hi!Mood prototype was hacked together by A-Pole during Hackitaly 2012 (more info). A-Pole is taking care of the electronic core, the design is Desall business! Desall is a crowdsourcing platform that, through design contests, connects companies and private clients with a worldwide community of creative talents. Every designer can sign up for free and participate. If you are a creative or a designer, we ask you to imagine and design the hi!Mood case: it must contain the controller board (maximum length and width of an Arduino Mega2560 PCB are 4 and 2.1 inches respectively), emit led patterns and play music through a speaker. If you manage to combine style with functionality, proposing a uniquely cool product design there is a big prize for you! Check the brief to know more about technical requirements, conditions and submission deadline. Link contest Good luck! May the best designer win. Acknowledgements: A-Pole, Arduino, Desall, Hackitaly, Openpicus, Stereomood.

Topic by Desall 


PETTY COIN BANK- initial stage. Can anyone help?

Hey Guys... need some advise and help on the initial idea and components of this project. PETTY COIN BANK: PURPOSE: - To electronically segregate coins, display the total number of coins per each case and the total monetary amount inside, with dispensing and security capability. FUNCTION: - Individual coins inserted in the coin slot will be segregated to go to the corresponding individual coin cases and each case will count and display the number of coins dropped in them and a general display for the total amount of money inserted in the device. With a security lock, the device is capable of dispensing coins. so What do you think? Some advise on how i can make this possible... I do have some ideas on the segregation and dispensing mechanisms of the project, and how to identify each of the coins from each other when inserted in the coin slot.My concern would be the Displays for the each NUMBER OF COINS that falls per case (3 displays in total), and the TOTAL MONETARY AMOUNT display that counts per inserted coin in the system. Of course when dispensing, the number of coins should be decremented and the TOTAL MONETARY AMOUNT would change as well depending on the coin and number of coins dispensed. And as you might have read from the purpose and function, this project intends to have a security lock for the dispensing mechanism. Anyone can put coins but only someone that knows the code can dispense coins. I plan on putting a keypad for that. but here is the thing... I DON'T KNOW WHAT MICRO-CONTROLLER I SHOULD USE. I plan on using ARDUINO, but what arduino should i use? and if someone can help i'd like a count of the inputs and outputs so i can decide on what to use. Thanks if someone helps on this...

Question by Gedon   |  last reply


How to build a clockwork robot?

Http://www.dailykos.com/stories/1632015#comment_65467648 To enter the Fukashima U2 with radiation at 1000 SVR plus can a clockwork autonomous robot gathering data with sonar be designed to go where no autonomous robot has gone before. The reason is all electronic devices would cease to function at about half that  SVR level. The clockwork mechanism would need to be designed to provide autonomous movement  so all sensors would have to be non electronic devices. Might mechanical sound, pressure, temperature or other forces be used for controls? Is it possible to provide a mechanical power storage source Compressed air energy storage (CAES) Fireless locomotive Flywheel energy storage Gravitational potential energy (device) Hydraulic accumulator Liquid nitrogen Thermal Brick storage heater Cryogenic liquid air or nitrogen Eutectic system Ice storage air conditioning Molten salt Phase Change Material Seasonal thermal energy storage Solar pond Steam accumulator Thermal energy storage (general) Chemical Biofuels Hydrated salts Hydrogen Hydrogen peroxide Power to gas Vanadium pentoxide What sort of time/energy is achievable?

Question by Rowland Whittet   |  last reply


How do I make a HERF gun from a magnetron?

So I saw this post here and I too am feeling creative and wanting to make a portable HERF gun powerful enough to make a ripe piece of fruit explode within less than 1 second. So here's some ideas about how this thing works: 1. The device would use a an appropriately sized vacuum magnetron with an electromagnet The current fed to the magnetron's electromagnet would be a rectified sine wave at the resonant frequency(oscillating current flowing in but not out of the electromagnets coils). The purpose of this technique is to use resonance to turn the magnetron into an amplifier as well as an oscillator so it functions as a maser of sorts(not sure if this has ever been done before). 2. This thing is going to need a lot of power, and I have a solution: pneumatic electricty. The electricity would be produced by means of a high speed electric motor with permanent magnets(which can act as a generator)that is capable of spining several hundred RPM without frying itself. This genemotor would be driven by a turbine spun by by outflow from a cylinder containing compressed air. When the trigger is pulled, the cylinder valve opens and the air is released into a small turbine chamber and then expelled out an exhaust tube extending out the back of the gun. My 1st choice of material for the gas canister is titanium since it has to be both compact and capable of storing compressed air at up to 1000psi(or above). But the big unknowns are a)how much power will be needed to suplly the magnetron and the RF oscillator/rectifier, b) how fast the generator will need to rotate to produce that power ,c) how much pressure is necessary in the compressed air canister, and d)what material I will need the canister to be made of. Any suggestions? Thoughts? Comments?

Question by YugZ0h0th   |  last reply


Can anybody tell me how to (further) check my VAWT charge controller for malfunctioning?

I have installed a Flexcharge NC25A-12 Charge Controller and an SE440 regulator in line between my VAWT turbine and its rectifier and the 1000 amp inverter. The turbine and controls charge four Trojan 105, six volt, batteries which are hooked in series parallel (two each in parallel, the parallels hooked in series). The turbine is a heavily modified Lenz-2 (vertical axis, three blades with spring-loaded furling & angle of attack control). It generates 108 to 140 Watts (nine amps at twelve volts to ten amps at fourteen volts) at wind speeds of fifteen to twenty five miles per hour. Nevertheless, I'm not able to charge the batteries. I think the Flexcharge charge controller is stuck, that inasmuch as the controller’s "Multi Function Indicator" function does show when batteries are low, when voltage from the system is low, and when charging is occurring (flashing and steady green light), but has never shown "divert" (to a heat sink). More, I have never been able to get the batteries to hold anything close to their individual 225-250 amp-hour rating. It's beginning to look like the batteries, purchased new originally, have sulfated on account of the charge controller panel not working. I note in using my multimeters that the cable at the heat sink indicates 2.85 volts, even when the batteries are down to 11.9 volts, and when the charge controller is not indicating "divert." When, moreover, an external battery charger (the automotive kind) is hooked in line and in lieu of the wind turbine and rectifier (these being disconnected from the controller, regulator, batteries, and dump load), the batteries indicate full charge on both hand-held multimeters and turbine system voltmeter and ammeter, but the charge controller does not indicate “divert” to the dump load heaters. Any ideas will be much appreciated. Thanks!

Question by taiosan 


Is it worth dropping $400 on a really nice oscilloscope (Rigol DS1054Z)?

I will describe my situation: I am a hobbiest that likes to make cool projects, and plan to get into maybe RF analog stuff, (maybe start out with making a few FM bugs, reverse engineer a simple video transmitter kit, and a few other things.) as well get into arduino some more, AC analysis (learn about Xformers, power factor, maybe some math, etc.) and I so currently have an old 2ch. 30MHz analog oscilloscope that is a PITA to make real measurements with. Not only is it huge and takes up a lots of space, but also I'm not even sure it is in cal!) I will be transferring into UVA (or maybe VT) for EE, and gone this summer for a NASA internship at langley. (maybe I will be able to take it with me w/ a toolbox of some electronics stuff!) The scope I am looking at (what appears to be what many subscribers seem to use, and/or claim is pretty good) is the Rigol DS1054Z. I only know how to use my $30 30MHz BKprecision scope I got on craigslist from the son of a father who was a TV repairman, and have NO experience with the use of the fancy-shmancy digital scope! What little I know is from watching EEVblog review of other scopes in the past. (I do know that they can be useful for 'capturing' waveforms, and can be set up to trigger on a pulse, maybe a certain digital codes, and that could come in handy for reverse engineering crap.) https://www.youtube.com/watch?v=7v-tFYbc7h8 https://www.youtube.com/watch?v=W2qdtQkBKhc https://www.youtube.com/watch?v=ETCOhzU1O5A https://www.youtube.com/watch?v=-gStNYfqMXk What sells it to me, being a complete newbie to electronics and digital scopes is that it has a nice big screen, the specs seem good (other certainly think, I have no intuition of what any of those things mean except the bandwidth, and maybe the sampling rate, 1GSa/s), 4 channels, intensity graded display, and it has loads of functions and stuff for me to grow into, and hacking it to make it think it is a DS1104Z is tempting, but I probably will not do that right away. Maybe once I feel what it offered is limiting. The deal breakers is the $400 price, a bit steep for me (cheap for something this good, apparently but still.), the fear that by the time I really start using it, it will be obsolete and the same money can buy some quantum super duper ASIC tech whiz bang 3GHz 100Gsa/s 1GB segmented memory spectacular scope! I am not really sure if it has a source, or signal generator either. Some sources claim that higher end ones do, or certain models anyway, and it seems like the official site say's no. http://www.rigolna.com/products/digital-oscilloscopes/ds1000Z/ds1054z/ That brings me to my next point. Should I also get a decent function generator? 

Question by -max-   |  last reply


Is it worth dropping $400 on a shiny new Rigol DS1054Z scope?

I will describe my situation: I am a hobbiest that likes to make cool projects, and plan to get into maybe RF analog stuff, (maybe start out with making a few FM bugs, reverse engineer a simple video transmitter kit, and a few other things.) as well get into arduino some more, AC analysis (learn about Xformers, power factor, maybe some math, etc.) and I so currently have an old 2ch. 30MHz analog oscilloscope that is a PITA to make real measurements with. Not only is it huge and takes up a lots of space, but also I'm not even sure it is in cal!) I will be transferring into UVA (or maybe VT) for EE, and gone this summer for a NASA internship at langley. (maybe I will be able to take it with me w/ a toolbox of some electronics stuff!)   The scope I am looking at (what appears to be what many subscribers seem to use, and/or claim is pretty good) is the Rigol DS1054Z. I only know how to use my $30 30MHz BKprecision scope I got on craigslist from the son of a father who was a TV repairman, and have NO experience with the use of the fancy-shmancy digital scope! What little I know is from watching EEVblog review of other scopes in the past. (I do know that they can be useful for 'capturing' waveforms, and can be set up to trigger on a pulse, maybe a certain digital codes, and that could come in handy for reverse engineering crap.)   https://www.youtube.com/watch?v=7v-tFYbc7h8   https://www.youtube.com/watch?v=W2qdtQkBKhc   https://www.youtube.com/watch?v=ETCOhzU1O5A   https://www.youtube.com/watch?v=-gStNYfqMXk     What sells it to me, being a complete newbie to electronics and digital scopes is that it has a nice big screen, the specs seem good (other certainly think, I have no intuition of what any of those things mean except the bandwidth, and maybe the sampling rate, 1GSa/s), 4 channels, intensity graded display, and it has loads of functions and stuff for me to grow into, and hacking it to make it think it is a DS1104Z is tempting, but I probably will not do that right away. Maybe once I feel what it offered is limiting.   The deal breakers is the $400 price, a bit steep for me (cheap for something this good, apparently but still.), the fear that by the time I really start using it, it will be obsolete and the same money can buy some quantum super duper ASIC tech whiz bang 3GHz 100Gsa/s 1GB segmented memory spectacular scope!   I am not really sure if it has a source, or signal generator either. Some sources claim that higher end ones do, or certain models anyway, and it seems like the official site say's no. http://www.rigolna.com/products/digital-oscilloscopes/ds1000Z/ds1054z/ That brings me to my next point. Should I also get a decent function generator?   

Question by -max-   |  last reply


Thoughts on Arduino/Raspberry Pi Idea?

Hi everyone, I am part of a research group at UC Berkeley working on a product involving the Arduino/Raspberry Pi. We are conducting market tests, and would really appreciate your help answering these questions. Thank you for your time! If you use Arduino/Raspberry Pi, how often do you use it? How do you use it? Would you consider it mostly a hobby or do you use it for school/industry as well? How were you first introduced to it? What are your general thoughts on the Arduino/Raspberry Pi? Did you learn to program by using the Arduino/Raspberry Pi or did you have some prior experience? If you had prior experience, how much? What languages are you well-versed in? Would you be interested in a model-based approach to programming Arduino/Raspberry Pi functions? This would be something akin to Matlab’s Simulink or Labview’s visual programming (flowcharts). The basic idea would be to remove the need to code in C. If you are not interested, why not? If you are interested, what specific features would you enjoy? Do you believe such a tool would be an efficient way to teach/introduce students to programming? In addition, here is a 1-minute survey (on a similar subject) if you are interested: Survey: https://docs.google.com/forms/d/1dkwyhC59I7h8IOuNFyL_tbjo7AFucTP0KQS0mYH1qy4/viewform

Topic by RobertB3 


THREE-DEE VIDEO from multiple lcd panels.

This morning I was watching television and thought to myself, "Wouldn't Good Morning America be so much interesting in three dimensions? This got me thinking, and I came to this idea: what would happen if you dissected a bunch of lcd monitors, removed the backlights, and stacked them. Then, you plug all of the screens into a processor that generates an image for each screen, and have a powerful backlight to illuminate these screens. I know that it is quite a stretch, but if one could work around issues such as the amount of heat produced and the cost of production, I think this could work. I think the best bet for input would be using RGB or CKMY on multiple panels, but I am not an expert in optics or any of that. So basically, this is an outline of what would need to happen, as far as I can tell: 1. A group of LCD panels that, when in a cascade formation and are fed sufficient data, produce a three-dimensional image 2. A bright backlight that is capable of illuminating said LCD group 3. A video processor capable of sending multiple signals to the screens that would produce a three dimensional image (as stated in point 1) 4. A cooling system to maintain component functionality 5. A benefactor or deep pockets 6. Lots of spare time If you have any ideas, please add them, I'd love to hear from the Instructables community.

Topic by student.mckinney   |  last reply


Old Phone That Can Play Games? Ideas...

Hi guys, so I was recently talking with my friend Omar about random stuff, and (like always) our conversation somehow got really off track and we ventured into the history of old phones (Nokia 3310...breaking everything we touch since 2000). We somehow got to thinking about how old bar style phones could be useful for the making community. My thought (which I incidentally shouted out as loud as a human can go) was this: what if we could put a really basic game onto the phone? Would it be possible with the current hardware? Maybe...and the controls are there, most phones have a D-pad with 12 keys (which could be special function keys in the game). I was thinking of games along the line of Doom, or any old FPS game...but in retrospect, that would be ambitious, and to be practical, a stick man game would probably be the minimum.  So my questions are: a) would it be possible for the hardware on the phone to be wiped of all software and would it be good enough to support the code. b) is it even possible to reprogram the phone, or even get some sort of bootloader onto the device? Probably not. And if not, is there any other way to put a game or any file onto the phone's hardware... I guess that's it. In general, would it be possible, and if yes, could anybody give me a few starters so I could try to do it? Thanks, Ivan

Topic by IvanT3   |  last reply


How to combine AT and ATX power supplies to power same system (motherboard)?

Hello,   I am struggling to upgrade a certain medical system . The device I have contains an old motherboard which powered by an AT power supply. My problem is that the power supply board (which supplies the AT power) has other functions, and there's no way to be replaced (by an ATX PSU). I already bought the motherboard: http://www.ibase.com.tw/2009/MB970.html , with INTEL core i5 CPU  Cry Cry. I can't risk my power supply board in attempting to operate the new parts (motherboard, CPU, 4 Gb RAM, CPU fan, SATA harddisk, and DVD), I believe it won't stand that kind of power consumption. I know you'll say this won't work at all -I know, but I was thinking about using voltage regulators to generate the 3.3 v rail from the same AT power lines. OMG I really need help about: How I can connect the AT and ATX power supplies to this motherboard (and to the other parts), ensuring that I am not risking my AT power board at all?. Another headache is that the AT power board has to work at the same time with the motherboard. And in order for the system to work the AT power board has to work (you know that a feedback circuit should be completed) that's why it should be connected to the motherboard.   This really became a challenge for me. I can't stop thinking, planning, and dreaming about it. If you have any idea or any experience about this, I would like and hope to hear from you...

Question by muhammad.shamut.7   |  last reply


Arduino Multiplexing Code Issue

I'm trying to select a pattern for 12 multiplexed leds (2x6) using the input from a pot. The different patterns are stored in arrays. To complicate matters two of the states include a blinking led, the first, redShift attempts to blink a single led, 1, using a for loop to step through an array. The other holds on leds 2-11 and flashes 12 using the same method. The input from the pot is diveded into 12 sections and a switch case is supposed to select the proper arrays to read from. Here is the code: //LED TEST 2 w/ 74HC595 //by Bwrussell 2013 //https://www.instructables.com/id/ /* Program Flow/Intent: Hardware: a 2 rows by 6 columns LED matrix running through a 595 shift register, arranged in a single line, and a potentiometer. The pot's input is divided into 12 ranges. These ranges correspond to incrementing LED patterns. There are 3 different types of pattern, the first blinks only the first, red, LED, the second covers 9 ranges and each one turns on an additional led, keeping those behind it on, the final type has all but the first LED on and blinks the final one. */ /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ //pin connections- the #define tag will replace all instances of "latchPin" in your code with A1 (and so on) #define latchPin A1 #define clockPin A0 #define dataPin A2 #define potPin A5 // analog pin for reading the pot's input. //looping variables byte i; byte j; //LED state storage arrays byte firstStates[] = {2,6,14,30,62,62,62,62,62,62}; //first row, non flashing, states byte secondStates[] = {0,0,0,0,0,1,3,7,15,31}; //second row, non flashing, states byte redFlashO[] = {1,1,1,0,0,0}; //row 1 states for red flashing byte redFlashT[] = {0,0,0,0,0,0}; //row 2 states for red flashing byte greenFlashO[] = {62,62,62,62,62,62}; //row 1 states for green flashing byte greenFlashT[] = {63,63,63,31,31,31}; //row 2 states for green flashing //Function variables byte dataToSend; //used in standardShift function byte redSend; //used in redShift function byte greenSend; //used in greenShift function //Storage variable byte normalState; //holds the array position for non flashing states byte redFlashingState; byte greenFlashingState; int rowOne; //passes the non flashing state of the first row int rowTwo; //passes the non flashing state of the second row int position; //holds the output from the potRead function void setup() { //set pins as output pinMode(latchPin, OUTPUT); pinMode(clockPin, OUTPUT); pinMode(dataPin, OUTPUT); Serial.begin(9600); } void loop() { position = potRead(); //read the current knob position switch (position) { case 0: //blink red led redShift(); break; case 11: // blink green led code here greenShift(); break; default: normalState = position--; rowOne = firstStates[normalState]; rowTwo = secondStates[normalState]; standardShift (rowOne, rowTwo) ; } } void standardShift (int firstRow, int secondRow) { byte stdArray[] = {firstRow, secondRow} ; for (i=0;i<2;i++){ //send data from ledData to each row, one at a time byte stdData = (1 << (i+6)) | (63 & ~stdArray[i]); // setlatch pin low so the LEDs don't change while sending in bits digitalWrite(latchPin, LOW); // shift out the bits of dataToSend to the 74HC595 shiftOut(dataPin, clockPin, LSBFIRST, dataToSend); //set latch pin high- this sends data to outputs so the LEDs will light up digitalWrite(latchPin, HIGH); } } int potRead () { int potRaw = analogRead(potPin); int potPosition = potRaw / 93; //returns a value 0-11 return potPosition ; } void redShift() { for (i=0; i<6; i++) { byte redArray[] = {redFlashO[i], redFlashT[i]} ; for (j=0; j<2; j++) { byte redData = (1 << (j+6)) | (63 & ~redArray[j]); // setlatch pin low so the LEDs don't change while sending in bits digitalWrite(latchPin, LOW); // shift out the bits of dataToSend to the 74HC595 shiftOut(dataPin, clockPin, LSBFIRST, dataToSend); //set latch pin high- this sends data to outputs so the LEDs will light up digitalWrite(latchPin, HIGH); } } } void greenShift() { for (i=0; i<6; i++) { byte greenArray[] = {redFlashO[i], greenFlashT[i]} ; for (j=0; j<2; j++) { byte greenData = (1 << (j+6)) | (63 & ~greenArray[j]); // setlatch pin low so the LEDs don't change while sending in bits digitalWrite(latchPin, LOW); // shift out the bits of dataToSend to the 74HC595 shiftOut(dataPin, clockPin, LSBFIRST, dataToSend); //set latch pin high- this sends data to outputs so the LEDs will light up digitalWrite(latchPin, HIGH); } } } I'm having two issues. First, the switch case doesn't appear to be working. I've monitored the pot input but there is no response from the LEDs. The second is with the for loops that are suppose to run the blinking. I know the loop on the inside will hold a pattern but in test code, without the pot, but adding the outside loop to step through the pattern array breaks it and the LEDs don't respond. Is the for loop running to fast to respond but not fast enough for POV? do I need a third loop that repeats each position but wouldn't that break the POV for the other LEDs? Or is there some stupid error I'm missing?

Question by bwrussell   |  last reply


Fabric cover for flash modifier - what's your idea?

After doing extensive web searches it is clear that no one makes a flash modifier / photo light reflector that meets my needs. The unit I have in mind would be the general shape of a small photo umbrella (about 16" in diameter), but it would function like a beauty dish. I want it to be collapsible and compact, yet durable enough to withstand many location shooting sessions. I have used the following basic frame construction technique on other projects and know that it will work for this one - I will solder together a reinforced (beauty dish shaped) frame structure that will be made out of small diameter brass welding rod and then add connection bracketing that will allow the photo reflector to be dismantled for transport. During my initial planning stages I thought I would just sew up a fabric cover (white on the inside, black on the outside) so that it would wrap around the frame on both sides. But then I realized that this was a very complex sewing job and that an easier method of covering this dish shaped frame might be to use heat shrinkable RC aircraft covering fabric. When I researched these materials on the web I discovered that they were very thin (just what you would want on a small airplane) and really wouldn't take any degree of wear and tear like you might expect during a photo shoot. So here's the question - what kind of fabric covering would be ideal for this photo reflector? It needs to be strong, lightweight, very flexible so that it can be molded around the contours of the reflectors frame and it should be paintable - white on the inside and black on the outside. Thanks for your suggestions

Topic by jmantze   |  last reply


wemos d1 mini blynk? display temperature&humidity?

this is my code and it works to display c&% on display and blynk app and it notifies me when it starts and run time, is there a way to display runtime/uptime on the display and should i remove anything? maybe add in code to send email when offline for more than 5 minutes? why does the screen go black when it updates? what other data can i display on the screen? it will be used to monitor server room temperature, thanks #include #include #include #include "Adafruit_SSD1306.h" #include #include #include #define OLED_RESET 0  // GPIO0 Adafruit_SSD1306 display(OLED_RESET); #define BLYNK_PRINT Serial #define DHTPIN D4 #define DHTTYPE DHT22  DHT dht(DHTPIN, DHTTYPE); // You should get Auth Token in the Blynk App. // Go to the Project Settings (nut icon). char auth[] = ""; // Your WiFi credentials. // Set password to "" for open networks. char ssid[] = ""; char pass[] = ""; BlynkTimer timer; void notifyUptime() {   long uptime = millis() / 60000L;   // Actually send the message.   // Note:   //   We allow 1 notification per 15 seconds for now.   Blynk.notify(String("Running for ") + uptime + " minutes."); } void sendSensor() {   float h = dht.readHumidity();   float t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit   if (isnan(h) || isnan(t)) {     Serial.println("where is my DHT sensor!");     return;   }   // You can send any value at any time.   // Please don't send more that 10 values per second.   Blynk.virtualWrite(V5, h);   Blynk.virtualWrite(V6, t); } void setup() {   // Debug console   Serial.begin(9600);   Blynk.begin(auth, ssid, pass);   // You can also specify server:   //Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 8442);   //Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8442);   dht.begin();   // Notify immediately on startup   Blynk.notify("Device started");   // Setup a function to be called every minute   timer.setInterval(60000L, notifyUptime);     // Setup a function to be called every second   timer.setInterval(1000L, sendSensor); } void loop() {   Blynk.run();   timer.run();   Serial.begin(115200);   dht.begin();   // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)   display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3C (for the 64x48)   display.display();   delay(5000);   // Efface l'écran et positionne le curseur dans le coin supérieur gauche - clear display and set cursor on the top left corner   display.clearDisplay();   display.setTextSize(2);   display.setTextColor(WHITE);   display.setCursor(0,0);   float h = dht.readHumidity();   float t = dht.readTemperature();   float f = dht.readTemperature(true);   float bat = ESP.getVcc();// / 1024;   // Check if any reads failed and exit early (to try again).   if (isnan(h) || isnan(t) || isnan(f)) {     Serial.println("where is DHT sensor!");     return;   }     // Température en Celcius - Temperature in Celcius // display.println("Temp.");   display.print(t);   display.println(" c");   // Humidité en % - Humidity in % // display.println("Humidity"); //display.setTextSize(1);   display.print(h);   display.print(" %");   display.display(); }

Question by turbiny 


Distance between two electronic systems sensor for the Arduino

Hello. I've been thinking about this for months and haven't figured out how to do it... Don't be frightened by the wall of text, it's a VERY entertaining read! You'll fall down laughing! ______________ The basics: Imagine two systems: A and B. Both A and B use the Arduino as their "heart". I want A and B to know, at all times, the distance between them. The distance is 3-dimensional, ie, it doesn't matter if A is in front of B, if A is on top of B, etc. The distance ranges from about 10cm to 2m. It's not that strict, though. Something around that... The final project (which is not the sensor; the sensor is just a piece of it, just like the Arduino or an LED or a resistor) is a gift, so it has to be 'good-looking'. Because of that, the sensor has to be as inconspicuous as possible. Problem 1: Linear solutions can't be used, like Infrared LEDs or Ultrasonds. Besides being too linear (which makes sensing in 3 dimensions too hard and expensive because of the use of arrays of LEDs or sound generators), the only way (that I came up with) they could be used is this (because it can't be based on reflections): 1- A emits signal (IR modulation or Ultrasonic frequence) and starts timer (microcontroller function). 2- B receives signal. B waits 2 milliseconds. B emits signal (different from the signal emitted by A, so they don't get messed up). 3- A receives signal and stops the timer. A then calculates the distance through a simple formula. That's how A would know the distance between itself and B. B would do exactly the same thing to know the distance between itself and A, but with signals different from those used by A (so they wouldn't get messed up). This is infeasible because: Using IR, every millisecond (the smallest unit of time a general microcontroller can measure) is equivalent to 30,000,000cm (or 300,000km or 186,400 miles). Using sound, every millisecond is equivalent to 34cm (or 13.4 inches). With such a short distance range (10cm to 2m), 34cm is too much, which makes the sensor incredibly inaccurate. Problem 2: Using the sensor with the Arduino The sensor would have to output something to let the Arduino know the distance so that I could then do stuff like: If distance is between 0 and 20cm, do this. If distance is between 21 and 50cm, do that. If distance is 51 and 200cm, do that. Else do nothing. etc. :) Problem 3: It has to be simple (and cheap) I'm no programmer nor do I know a lot about electronics. I'm a simple hobbyist with the dream to finish this project, so it can't be overly complex. :) So, after reading this wall of text, what do you think I could use? Do you know any wireless technology that lets me do this? Oh, sorry about claiming it would be a fun read.. It was the only way I found to make you ACTUALLY read this. :p THANK YOU! :D

Question by pedrotome   |  last reply


Peltier-element: Limiting its heat by tapping the power?

Hi I have a question based upon logics and the function of a peltier-element. we all know, that you can supply power to a peltier-element to raise the temperature on it one side and lowering it on the other. So it increases the differential. Now: If we heat the "cool" side and try to radiate the heat off the hot side (eg cooling it a bit), we can get a small amount of energy off the peltier as electrical current. The current depends on the temperature-differential: The bigger the more. OK so far. Nothing new. But what made me think was the fact, that you have 2 opposite states: Heat Side C and cool side H --> Get energy out in proportion of heat-differential. Put energy in --> Side C gets cooler and side H gets hotter in proportion of energy supplyed. By getting energy OFF the peltier, you in some way, redirect some parts of the heating-energy to the electrical-output. Also that is nothing new and we all know that since energy cannot be generated but only converted (in our case from thermal energy to electrical energy). Now what puzzles me is: Does it actually affect the temperature (-differential) of the peltier, if you get energy off it? Lets imagine the following experiment: - You build something like in https://www.instructables.com/id/Candle-Powered-Electric-Candle/ - Now you disconnect the load (lamp) and measure the temperature on the upper side (Away from the candle). - Wait for a steady-state when the upper side doesn't get hotter - Now turn on the lamp thus redirecting a bit of energy away from the peltier. - measure the temperature again on the upper side. Does it lower the upper temperature a bit? of course it wont be lower than the unheated state. But lets say the steady state was 55°C. Would it be like 50°C if i switch on the lamp?

Topic by Orngrimm   |  last reply