voltage level monitor circuit ?

Hello, So for my application, i need to have a circuit that can monitor the input voltage until it reach 5V (usually from 0V ) then switch on and allow the 5V to flow into another circuit.  The problem is i have no idea where to start. Can anyone help me ?  Thank you very much

Topic by ChuongV1   |  last reply


Power Tool Corded to Cordless

Hi 'nstructables I'm building a hovercraft (see several tutorials on Instructables - the one with a leaf blower) and my leaf blower is corded. I don't want to buy 25 miles of Black and Decker High Power Extension Cabling so I'm planning to convert to cordless. Here's my idea: (in visual) Is there anything I need to add? And if so, how do I make the "12VDC-240VAC" inverter described? My blower is 1600 watt. Thanks for any help! (Black and Decker)

Topic by nitrojon   |  last reply


How to replace damaged LCD in iPhone 7

Yesterday while getting out of my car, my phone slipped out of my gym shorts and hit the sidewalk. I came to a complete halt and slowly but carefully picked up my phone. "Maybe it got a couple of scratches and that's it?" But when I flipped the phone over, I discovered that it had a bunch of spiderweb cracks. I would like to repair this myself, I found a good video guide: https://www.youtube.com/channel/UCxKlNJ577sGSnZAb5fLPD1g Should I follow this instuctions, I think it is pretty decent job, what is your opinion?

Topic by jerry9spinger1   |  last reply


Wireless Button Pusher

Hello all, I am trying to add/build a wireless button pusher to a grain management device on my farm. The device cannot be hacked into or tampered with, however, the button I am trying to push requires little force and does not need to be sustained. It only needs to hit the button when I hit a remote. Additionally, I cannot use a phone for this (my grandfather needs to be able to operate it as well and could not use a phone) So I would need to be able to connect two simple remotes.  Any and all suggestions welcome. 

Topic by larx   |  last reply


Not able to enter in the "Make It Move" contest

Hi there, I want to enter for the "Make it Move" contest with the instructable I posted a week ago, but the site doesn't show the option. I read the instructions and it says that you can enter with your previously published instructable. Please help. 

Topic by Mayur BK   |  last reply


Converting solar LED string lights to a wall wart adaptor.

Hi all I recently picked up some bargain priced solar string lights for room decoration and to provide a low level of light at night, I suffer from Meniere's disease and one of my triggers is moving around in complete darkness, unfortunately I also have problems going from darkness to light so simply turning on a light can also trigger an attack. I've tried all manner of different lighting but most were not suitable for a variety of reasons. A friend who is also a sufferer suggested LED string lights, the kind used at Christmas or to give some decorative lighting in gardens, he has similar problems with light and darkness to me and had been using them for several years he now has LED lights set into coving in every room of his house, I borrowed a loose string set of his he uses on some plants in a small conservatory while he was away on holiday and to use the same words I did to him on his return they were "Bang on perfect" bright enough to be able to move around comfortably (imagine a couple of candles in a bedroom) but not so bright that they keep me awake. I've had solar lights in the past and knew that the bargain price was probably because they had been in storage for some time so was not in the least surprised to find the batteries no longer take a full charge, I swapped out the old batteries for new ones but to be honest I bought them more for their look than the solar capability, I was originally seeking some mains ones but not wishing to have a hundred or more all I could find were solar or battery, I really don't want the hassle or expense of constantly replacing batteries and the solar ones come on automatically at night so it seemed a good compromise, unfortunately I'm still having problems, whether it's an issue of their not getting sufficient charge from the autumn sun to fully charge (the panels are stuck to my windows so are in full sun all day) or simply that the batteries are running down too soon they are just not lasting long enough for me to rely on them. What I would like to do is change the power to a mains wall wart, each string is powered by a singe AA 1.2v 600mAh battery and I'm hoping I can swap this out for a hard wired adaptor of suitable output. I'm not really an electronics/electrics guy, I can build wiring looms for motorcycles OK, I've made some simple additions to the circuits on my electric bike to power an alarm and installed 12v LED car bulbs into its lighting but that is all very simple low voltage stuff, I don't have much experience with converting from battery to mains. My questions are pretty straightforward and I'd like layman's answers, a whole lot of technical chatter about amps living in Ohms and suchlike will get me nowhere, all I want to know is is it a viable option and if possible where I could obtain the necessary adaptors suitable for UK 240v mains electrics online. These are the only tech specs I have on them that seem appropriate to my question are they are Solar Power: 2V 100mA If it's any help these are the lights in question. https://www.amazon.com/Finether-Festival-Celebration-Decoration-Commercial/dp/B01M6CLVQX Thanks in advance for any help ideas and suggestions. NG.

Topic by Nostalgic Guy   |  last reply


control the speed of the ac fan by pic with PWM

Hello I would like to know how to control the speed of the ac fan by pic with PWM I used optoisolator to protect the pic but the circuit does not work well is the optoisolator doing his duty ? is this circut working properly ? please help me  

Topic by MohamadK4 


DC motor regulation

I am planning to build a small gearbox that depends on a steady rpm from a 3V dc motor. I understand that the output rpms will change in correlation to the fluctuation of input power. My question is, if I used a regulator to regulate the input voltage from 5V to 3V, will that keep the motor rpms steady?

Topic by Tman179   |  last reply


Chips in smoke detectors

I have a bunch of smoke detector circuit boards all of which have IC chips. All of them have slightly to widely different numbers, some Motorola, a philips, etc.  The main question I have is what type of chips are these as far as function goes? I tried looking these up but so far nothing absolute. Some numbers I remember are 8506, 8605, 8502; other numbers are way different and I don't remember what they are.

Topic by eramsell   |  last reply


Low Gain in RF filter after the signal goes through the switch 2-18GHZ

Having trouble with an RF switch, getting low gain as it passes through the switch, I have x-ray the component, and all links are intact, no ESD damage that i can see, Does any one know what could be causing it to have low gain? possibly the RF track in the Switch? HEEELP?!?!!

Topic by SamuelG122 


How do I regulate voltage on a multi-amp battery charger.

I know very little about electronics. I have a car battery charger that outputs in 12 voltsDC. It is also "switch" selectible for 2 or 10 or 50 Amps. Once I select one of these choices 2/10/50, I would like to vary the voltage up and down from 1v to 12v. How do I build something that will vary the voltage at each of these amperage levels. Thanks- Steve

Topic by st600r   |  last reply


Rover: Tracks or Tyres?

Hi guys, I'm building an adaptable rover system which should be designed to go over rocky/muddy terrain (just imagine the basic farm environment). As i am doing this for an A level project, can you help me decide whether tracks or normal wheels would be better? Thanks!

Topic by DELETED_ThunderVolt99   |  last reply


Can an SD card port provide USB power?

I have a device that's designed to get its power from a USB port, but where it mounts there is no port available.  However, there is a fullsize SD card slot.  From what I can tell it *appears* I could rig up an adapter that delivers power to the device through that card slot, but am I reading this correctly?  And more importantly, would this deliver as much power as a USB port? Thanks!

Topic by Spunk-Monkey   |  last reply


Motion Sensor Mp3 Stereo PLayer

How would I would I go about making a Motion Sensor Mp3 player using my Stereo.  I want to have the ability to play an mp3 file using my Stereo when people pass nearby the sensor.  I want something loud and very realistic.  I am unsatisfied with the reviews of the below mentioned products.   I want to be able to play the mp3 file - motion sensor using my stereo player. https://www.amazon.com/dp/B071YFP2GG https://www.amazon.com/Mini-Motion-Activated-Audio-Player/dp/B019R07FR4/ref=sr_1_7?ie=UTF8&qid;=1505256883&sr;=8-7&keywords;=motion+sensor+mp3

Topic by WesleyK18   |  last reply


Frigidare / Electrolux FRT04L5DB0 Refrigerator

Anyone know how to get the freezer door apart to switch the hinge on this unit?

Topic by Red Gym   |  last reply


on attiny85 chip, how to control servo motor with IR sensor?

Hi i would like to know the coding which is to control servo motor for using IR sensor on attiny85 chip. i can do with arduino but attiny85 is not same as it. what i want to control is simple press button (0x01FE847B) to move servo motor 180 degree press button (0x01FE44BB)to move servo motor 0 degree https://photo.cloud.naver.com/v2/# please help me

Topic by kclook   |  last reply


how to control servo motor for using IR sensor on ATTINY85??

Hi i would like to know the coding which is to control servo motor for using IR sensor on attiny85 chip. i can do with arduino but attiny85 is not same as it. what i want to control is simple  press button (0x01FE847B) to move servo motor 180 degree press button (0x01FE44BB)to move servo motor 0 degree please help me  http://naver.me/GkO2S4ik

Topic by kclook 


Voltage regulator for trailer brakes

Im planning on building a motorized trailer dolly for my travel trailer, however i want to make a dead mans switch for the trailer brakes.  I was wondering if I took apart an old cordless drill if I could use the trigger as a voltage regulator to regulate the voltage to the trailer brake system.  Without getting into specifics of how it will connect to the regulator, I figure I would have like a bike brake handle that while applied the trailer brakes would be off, but if released that the trailer brakes would be applied incase the trailer started to roll away from you. Any suggestions other than "Go buy a trailer brake controller" would be appreciated! :)

Topic by Thunderbone   |  last reply


Arduino with multiple RGB LEDs

Hi, I am pretty knew into the Arduino world. My problem is trying to make multiple RGB leds (https://www.banggood.com/10pcs-5mm-RGB-LED-Common-Cathode-4-Pin-Tri-Color-Emitting-Diodes-F5-p-937475.html?p=DQ30066511122014069J&utm_campaign=educ8stv&utm_content=huangwenjie) work with the Arduino. Although it would be be easy enough to use a single RGB led, I want to use multiple RGB leds. My RGB led uses 3 digital pins with pwm but since i am using an arduino pro micro with 5 pwm pins, I can only use 1 led. I have found that the max current per pin is 40ma but shouldn't exceed 20ma so therefore you couldn't put 2 leds. So my question is, how would i power more than 1 RGB led? Any help will be appreciated. Thanks!

Topic by Isaac Emery   |  last reply


airborne Micro generator from nitro rc 40 motor / 400kv outrunner / smart charger / lipoly

Concept : design onboard lipoly charger system to extend flight time on giant scale electric plane.  1) if this is even a worth while project, the trade off of course is weight / power ,      can enough be created from a micro generator to make a differance, or would additionals 6 cell lipoy be more sensible ,  configuration =   OS max 40 nitro motor /  brushless 400 kv outrunner / ac / dc conversion rectifier / dc voltage regulator / 12v dc lipoly balance charger to main bank of lipoly batteries /  motors 2) I don't know how to build the rectifier bridge, so I would need some direction  Any suggestions or thoughts on this project are appreciated.  Jeff

Topic by JeffR135 


Hacking an audio greetings card - to prevent erasure of audio-clip

I bought an audio greetings card as I wanted the recording device to put in a craft project. I've recorded the 20 second audio clip and I want to prevent accidental erasure of said audio clip. I have 2 short questions... Which wire or wires do I cut in order to disable the record button?? Can I chop the (now redundant) mic out completely (as I'm trying to reduce the thickness of the sound module as much as poss) without affecting the sound clip, will it still play if the mic is no longer in the circuit? I've included a photo showing the record and mic buttons, and the wires going to and from them. Many thanks for any advice offered :o)

Topic by badrobot-uk   |  last reply


Control Garage Door with WeMo Help

Hi everyone, I am a beginner with anything that has to do with electric circuits and I need your help. Recently a WeMo light switch came to my hands and I thought it would be a good idea to use it as a wifi remote and as a regular switch, of course, for my garage door. I thought maybe someone on this forum could guide me to install the switch to the circuit board of the garage door. i have also attached some pictures of the garage door circuit and the switch. Thank you for your help

Topic by dark0mlks 


Manipulating temperature in garment steamer

 I have a garment steamer. As a school project, I need to do an innovation where I need to add temperature regulator features. I have read that irons use thermostat to control the temperature, how do i install a thermostat in the steamer or is there other ways to regulate the temperature. By the temperature regulator, i should be able to produce the right amount of steam at the right temperature for each fabric.

Topic by WafiqahK 


Can I use this motor for diy wind turbine project ?

Hello, I have this motor: SHINAKO TOKKI X7807-201V Single Phase Motor 230V same like this: http://www.ebay.com/itm/381696549483?rmvSB=true I am interested can I use for Wind Turbine ? Thank you

Topic by Chief.Wolfinjo   |  last reply


Need help building a scoreboard with arduino 101 and 12v LED strips

SOS HELPP! Im trying to build a scoreboard with 12v led strips, large digit drivers shift registers (TPIC6C596) and arduino 101 but im not sure how to build it. i have used this drivers before in a 4 digit  clock and the drivers based on another project i saw here in this page, but im not sure if i can use them for the scoreboard.This arduino 101 has a bluetooth componet integrated and im planning on using it to control the scoreboar via bluetooth but if can come out with an other idea it will be great, but i have very limited time and parts and im kind of new to arduino and the whole poject stuff. if you can help me with anything ill be very thankful.. here its the link for the drivers https://www.sparkfun.com/products/13279

Topic by kahboni   |  last reply


Connect multiple Reed Switches to one Raspberry pi

Hi, I was wondering if its possible to connect multiple reed switches to 1 Raspberry Pi so i can get notified whenever 1 or more switches gets triggerd. thank you.

Topic by archi0112   |  last reply


My Arduino board affected by opening or closing any key to open any lamp in my house

i am an Amateur in electrical engineering  i learned a few thing  about micro controllers and i mad a project this project about light switch trigger by laser the project Component of 1- Home made Arduino board 2-home made relay module 3- home made voltage regulator 4-tow 5V 1A adapters 5- laser 6- photo resistor   the voltage regulator  take the power form the first adapter to supply 4.8V to the voltage regulate to out 4.8V to the laser and the laser pointed to the photo resistor and the adrduino board take the power from the second 5V adapter  looping on when the photo resistor value less than 750 then switch the relay module to high and delay the code for 10000 M Seconds and then switch the relay to low and end that is the project    BUT........? when i installed this project to the real live on stairs fluorescent lamp .... first it takes a while to trigger the relay switch  and the biggest problem i do not know why  when i open any near by switch to open or closing any of my hows lamp its trigger the relay on and then the rest of the code  continue normally not this only also when i insert any near by plug its look like some how connected to electricity   I Rely Do not know the problem where  and the schismatic for adrduino board , relay module and voltage regulator attached cold any body please help me

Topic by i_sadek   |  last reply


Arduino + Stepper

Hi! I have an Arduino nano and a Minebea PM55L stepper motor and I have to connect these two together. I read the Arduino tutorials, and got a ULN2003 chip. The thing I am unsure of is the power supply and which wires of the motor do what or should be connected to what. There's 6 of them and I really don't want to fry anything if at all possible. Could somebody help out, please?

Topic by TashaDax   |  last reply


Arduino Mega with Sim900

Recently I bought Sim900a module and Arduino Mega 2560 to run my old code for sending sms and call, but now there is a problem as I am unable to send sms or either call, my code is attached below. #include SoftwareSerial gsm(2,3); void setup() { gsm.begin(9600); // Setting the baud rate of GSM Module Serial.begin(9600); // Setting the baud rate of Serial Monitor (Arduino) delay(100); } void loop() { if (Serial.available()>0) switch(Serial.read()) { case 's': Send(); break; case 'r': Recieve(); break; case 'S': Send(); break; case 'R': Recieve(); break; } if (gsm.available()>0) Serial.write(gsm.read()); } void Send() { Serial.print("Sending"); gsm.println("AT+CMGF=1"); delay(1000); gsm.println("AT+CMGS=\"+xxxxxxxxxxxx\"\r"); // Replace x with mobile number delay(1000); gsm.println("Hello I am GSM modem!!!");// The SMS text you want to send delay(100); gsm.println((char)26); // ASCII code of CTRL+Z delay(1000); } void Recieve() { Serial.print("Receiving"); gsm.println("AT+CNMI=2,2,0,0,0"); // AT Command to receive a live SMS delay(1000); }

Topic by vicky58911 


LVDS board with raspberry pi

Hi there, I recenlty purchased a M.NT68676.2A LVDS board and connected up to my raspberry pi. All of this is working fine however the setup at the moment looks like frankensteins attempt at a pc, so i was wondering what is the best way to go about building a box to contain my setup, bearing in mind i have no CAd or the like expereince and no access to a 3d printer (no small ask i know) I want the box to be able to support a 15" laptop screen and have the ports accessible on the outside. Look forward to some ideas. Thanks

Topic by RobertW292 


Kids Robotics

I want to work with my daughter to build a fun robot but it seems like there are some many choices out there for platforms, controllers, software etc. I think I'm leaning towards a platform from DFrobot. http://www.dfrobot.com/index.php?route=product/product&path;=37_111&product;_id=97#.VaL4sZNVhBc And an Arduino based controller like this, http://www.dfrobot.com/index.php?route=product/product&path;=35_104&product;_id=1176#.VaL45pNVhBc To control and make it move I'm thinking that Ardublock could be a good choice. http://blog.ardublock.com/ I'm curious if this community has any thoughts on my choices... or alternative ideas. Thanks, Phil

Topic by filthyPhil   |  last reply


how to write a program to control switch and LED

This program is based on How to Program Switch and LED Connected with PIC16F877A. http://www.kynix.com/BlogImage/9.4.7.png    The following code demonstrate, how to write a program that scan the switch status and turn on and off LED. The switch is connected at PORTE bit-0 and LED connected on PORTB bit-0. When switch is read as high state, the LED is turn-on and when switch state is low, LED is turn-off. The switch debouncing rate is 5msec. The code is written in “mikroC PRO for PIC v.5.6.1” IDE and simulation is done with Proteus 8.0 SP0.  PIC16F877A-I/L Datasheet Code in mikroC [code] // switch connected on porte #define SW_AT_PORT PORTE // debounce rate 5msec #define DBOUNCE_RATE 5 // direction signal sbit LED_dir at TRISB.B0; sbit SW_dir at TRISE.B0; // bit labels portb sbit LED at PORTB.B0; sbit SW at PORTE.B0; // old state save flag bit oldstate_one_to_zero; bit oldstate_zero_to_one; void main(void) { // set porta and porte as digital ADCON1 = 0x06; // set direction as output LED_dir = 0; // set direction as input SW_dir = 1; // init LED LED = 0; // init old state flag oldstate_one_to_zero = 0; oldstate_zero_to_one = 0; while(1) { // Detect logical one if(Button(&SW;_AT_PORT, 0, DBOUNCE_RATE, 1)) { // Update flag oldstate_one_to_zero = 1; } // Detect one-to-zero transition if (oldstate_one_to_zero && Button(&SW;_AT_PORT, 0, DBOUNCE_RATE, 0)) { // Update flag oldstate_one_to_zero = 0; // LED ON LED = SW; } // Detect logical zero if(Button(&SW;_AT_PORT, 0, DBOUNCE_RATE, 0)) { // Update flag oldstate_zero_to_one = 1; } // Detect zero-to-one transition if (oldstate_zero_to_one && Button(&SW;_AT_PORT, 0, DBOUNCE_RATE, 1)) { // Update flag oldstate_zero_to_one = 0; // LED OFF LED = SW; } }} [/code]

Topic by narne   |  last reply


using Smart TV board from dead TV to make standalone player

Hi everybody, recently I hired a new ISP company (italy) with a SO AWESOME VOD TV service, like netflix and also live tv, , the app works very great and with a good quality, the problem it's only available for LG and SAMSUNG smartTV, no way to watch it on PC; mobile, chromcast.... So... i have 2 more Sony TV and a 4k Projector and i don't find a dam solution to watch this app on rather than buy another 2 LG/SAM tvs and throw the projector (which is not an option hehe) So I wonder if I  can just buy a broken LG/SAM TV (even a new one) and use the smart TV board as player, I think, it's pretty easy to just unattach the board and put a power supply, but i wonder what kind of video interface this board uses, I will need any kind of magical WHATEVER to HDMI converter, and also it need to have audio aswell  I read most of the TV use proprietary interface / connector to send image to the panel, the app it's compatible with more than 200 models from LG and Samsung, maybe you guys know the exact model i shloud find to "hack" the board in most easy way Thanks! 

Topic by srcastor   |  last reply


PDA screen for Raspberry Pi

Does anyone know if I could use a Dell Axim x51 screen as a monitor for my a Raspberry Pi and if so how? Thanks Denny

Topic by Leviset 


Project Idea

Im sick of checking for mail throughout the day so i was hoping to setup some sort of motion sensor in my mailbox that trasmits to my home with a beep or light. Any ideas to achieve this cheaply?

Topic by andrewlapham2010   |  last reply


Batch Program ideas

Hey everyone! ive made only two batch programs, as you may or may not know. i need ideas, anything that you suggest, i can make!! (no moving games, cant do that) but anything else you want me to make, i can and WILL program it. its your chance to express yourselves, i need ideas!!      *dont give simple ideas, i like chalenges ;)

Topic by Country Boy 97   |  last reply


Which Stepper motor and which controller?

Hello, Still in research mode for my own CNC machine which will be Arduino based. But, as everyone is using different motors and controllers (drivers?), how do I choose the right one for me? My machine should be able to do soft materials like wood and plexi/acrylic but I als want to be able do mill/cut aluminum, as I am restoring an old car and parts are not easy to get hold off. For my board I was thinking of an Arduino UNO (like most) but then, which motor to go for? Uni or bipolar? 17, 23, 34? And which driver? gShield / CNC Shield V3 / Dual step driver? A4988? 1 board per motor or can I combine them? How to get a smoother run then 1/8 steps? (Found CNC Shield V3.0 + UNO R3 + 4pcs A4988 Driver for £15???) I have never soldered anything, but I am a fast learner. So far when it comes to electronics, I managed to hardwire a stereo without harness into my car, speakers, radiator fan circuit and some door controlled LED's. Far away from soldering of building a CNC, but I am up for the challenge. I know there are a lot of questions in this post, but I appreciate any explanation why someone chose one motor over the other etc.... Any information is highly appreciated. I rather research more then building something and then have to start over again. Kind regards, Red

Topic by redmarien   |  last reply


DIY Solder Pot

Just today, my brother offered to give me his old coffee maker that he had replaced with a newer one. He is well aware of my electronics hobby, which is why he offered to give it to me in the first place. Nothing is wrong with the coffee maker electronically - he just didn't use it for a long time in which it became moldy on the inside. He cleaned the inside properly, and as a precaution I did it a second time. Now that it is cleaned, I'm curious as to if I could turn it into a solder pot. Seeing plenty of DIY solder pots, I'm thinking I could use an empty soup can, cut to a reasonable size, and have it rest on the heating element of which the coffee pot would normally rest on. Would I be able to do just that or no? Any suggestions as to what to use for the "bath" or "pot" of which will hold the molten solder? Thanks in advance! P.S. This is a basic electric drip coffeemaker I'm wanting to salvage - just to clarify.

Topic by TXVisual   |  last reply


Ardupilot V2.5.1 vs. PiZero

Hello I have a PiZero and an ArduPilot and I want to know if I can use each components on separate projects or do I have to use both of them together? As you can probably tell I'm a noob to drone building and I'm trying to create my own intelligent Drone with a RoboCat Frame and Cover. Can Somebody Please explain to me the difference between these two components and some best practices for building this drone?   P.S. I'm trying to build a submarine drone as well  Cheers!

Topic by JasonT81 


How to Charge 7.4v Li-Ion Battery Pack with CCCV

For one of my project i need to use 7.4V Li-ion battery of 2200mAh, Now i need to charge this battery pack efficiently. I'm searching for a charging circuit for the same but what ever i'm getting is a 3.7v charger or a charger not following CCCV methord. as mentioned in following link Link: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Please suggest me a way to charge and discharge my battery in a better way.

Topic by ASHMILH 


wiring and charging 2 3s1p lipo batteries in series?

If i wire three 3s1p lipo battery packs in series, does it become a 6s2p battery and can I charger the 2\three batteries in that form(series). This is for a electronic long board battery. I would be using three zippy compact 5000mah 3s1p 11.1volt batteries.  Im want the total mah to be 5000 and output voltage to be 33.3. therefore the wirng like this would work but im not sure if i can charge it in series with 1 charger or if i have to charge them all seperatly if wired in series.  Thanks!

Topic by bluebox17   |  last reply


rc project

I decided to go for the rc car. I'm using the 1/5 scale  maxstone trying to combine it with the raspberry pi. I'm also using adafruit's pwm. I know this might be old to others but it is new to me. I am a beginner and I am very excited about it!    I am open to any suggestions, comments, feedback, links, anything would be great!

Topic by SMILEY4242   |  last reply


MPF102

Hi, I'm trying to build Ruby guitar amp for my brother, but my problem is that I can't find this MPF102 transistor or any of its equivalents where I live. and if I order it online it will cost me as much as a Marshall amp costs. I will appreciate any help or suggestions whether to replace the transistor or modifying the circuit.

Topic by soranblue   |  last reply


android app -> raspberry pi -> arduino !!!

Hey! I want to make a very simple android app with buttons... Each button has to be a "shortcut" for a specific command which will be sent from my phone to raspberry pi 3 with ssh.. These commands will simply power some arduino pins to give 5V ( like ser.write('3') which turns on pin 3 ). But I can't figure out the way to do what i describe with bold... Any help??

Topic by ΦώτηςΘ   |  last reply


programming help

First of all, I am new to this. But for my CEIS course project I decided to program an rc vehicle because I thought it would be COOL! Now I am knee deep into the project and I am needing guidance.  So I am going to attempt to stack raspberry pi hats. One adafruit pwm for servos and the other adafruit pwm for dc and stepper motors. The first thing I done wrong was solder the gpio headers on backwards. Since I'm not too professional with a soldering iron I ended up making the drives of no use and ordered more. Before I done that, I got my pi camera working! Still need to program the pan/tilt servos. I have battery power, wiring, almost everything as far as hardware. Just not sure if I am headed in the right direction. I tried different things with python and the i2c but now when I start up the Kernel Module fails.  Any help will be great!

Topic by SMILEY4242 


ESC,Battery,Motor selection for quadcoter

Hi, I am a beginner to build a quadcopter. so please help me in selecting ESCs , lipo Battery and Motor to make my own. I details of the parts are listed below : Brushless Motor : Brand: Racerstar Item name: BR2205 2600KV Brushless Motor RPM/V: 2600KV Height: 31.5mm Width: 27.9mm Shaft diameter: M5 Motor mount hole size: M3 Weight: 28 grams Voltage: 2-4S Battery: 2-4S lipo battery Max.current: 23.2A Max.power: 710W Internal resistance: Ω Usage: for 250 260 280 Multirotor Frame Kit Lipo Battery : Brand : Lion power  Configuration :  3S 11.1v Maximum continuous discharge rate : 30C Capacity : 4200MAH ESC : Sustaining Input Voltage: 6-12V BEC Output Current: 5V/3A Continuous Output Current: 30A Max Current: 35A/12s  I just tested a brushless motor mentioned above with the esc and battery while the motor is running for about 10 seconds the esc is burnt.So is to possible to build a quadcopter with the parts listed above please help. Thank You

Topic by rsudhar00123   |  last reply


Arduino 2:1.0.5 ide cant detect yun shield over wifi

Hello I'm setting up my Iduino yun shield for the first time and everything was running smoothly until I checked my serialPort option under the tools menu and I get no iduino wifi option, just the same regular old (USB0). do I need to do something with the firmware or what? the board pops up on the menu as Arduino uno --Iduino Yun but thats it. Also I'm running this off of a Raspberry Pi3. Thanks For Listening Any suggestions would be much appreciated

Topic by JasonT81 


How can I slow down my electric leaf blower?

I have a 18 volt battery powered leaf blower. It has two speeds. How difficult would it be to slow it down a bit so the battery lasts longer? Right now even on the slowest speed it blows way more air than what I need.

Topic by Qwerty1794   |  last reply


Need help with Led project (time sensitive)

Need help with Led project (time sensitive) Hello I am currently working on a project that has less than 3 weeks till the suspense date. One aspect of the project I will be adding some LEDS. I want these LEDs to flash. So I got the following stuff for this project: LED Flashing kit MK102 by Velleman from Fry’s Electronics 100 rectangular flat clear 2mmx5mmx7mm LEDs (DC 3V 20mA) 400 DiCUNO 3mm LED assorted colors Forward Voltage: R/Y 1.8-2.2V B/G/W 2.8-3.2V Max Current: 20mA The issue: Ok so I want to take the LED flasher kit and instead of using the two supplied red LEDs I want to run two series of LEDs. One series will have two flat clear LEDs and one clear 3mm LED. The second series would have one flat LED and one 3mm clear LED. I have other colors but I figure if I stick with the clear LEDs, it makes everything simple and I will simply paint the LEDs the color I want. I would like to use all the other circuitry that comes with the kit and simply add each series where you would normally add the two red supplied LEDs. This kit runs on a 9 volt battery. So, I am assuming that I can simply replace the supplied resistors that come with the kit with ones that account for the LEDs I want to use? I am attaching the diagram from the kit for clarity, I hope this is making sense. Any help you can offer would be appreciated.

Topic by 11b30b4 


How can I multiply/double (or just increase) voltage in a DV 5v curcuit ???

ok i have the following parts to ue for this: (all leftovers from former project..)  :) 1x mosfet IRF510 power transistor 5,6A 100V 9x 2N3904 amplifier transistors 40V 0,2 A .0.625 W ~16x 1uF capacitors 50V ~99x recifier diodes 1A 50V ~35x 2k resistors  0.25 W the idea is to charge a battery pack consisting of 4x 1,2-1,25V = 4,8-5V 3000mah AA nimh batteries using my 5v usb wall charger that has 1A output! i tried connecting the battery pack directly to + and - and 'i think' its starting to charge but after 1-2 hours at full rate (5v 1a) it should be at least 50% charged (3 hours would be full charge -> 5W x 3 = 15W), but if i connect them they last for about 2 -3 minutes and then empty again!! so after this im concerned that i might need at lest 6V-10V to achieve the desired effect !!  -> charge 15W NIMH batterpack with wall charger (nokia ac-60e.. 1-1,5A) i nless than 3 hours (as like a phone would need !!) therefore i need a cuirciut (ONLY DC) to double my 5V OUTPUT to 10V (yiou shouldnt apply more than twice the curent of a batter pack) or ideally 6-7 V but i dont know if thats possible without a swiching IC or more different resistors.. so just doubling would be nice at the moment!!  

Topic by sblocc10   |  last reply