Led light

I'm struggling understanding what im really needing and could use some guidance... I'm tring to build a underwater fishing light that has 36 3watt green leds.  I'm going to only be powering them when the engine is off and the batteries aren't being charges... it will run off a standard 12volt marine battery... the led specs are ' green (510-530nm):DC Forward Voltage:3.4V~3.8V Forward Current: 700mA'.  what would be the best way to power these leds... im assuming that I need to power in series groups of 3. but with such a wide voltage of 3.4 to 3.8... do I just shoot for the middle? do I use 12v in my calculation or do u use like a 12.5 or 13 like it sometimes checks.... Can I get by powering it with just resistors or do I need a led driver? I have entered my data in some of the calculaters online and it says I need a 2.2 resister but gives warnings... and doesn't say what watt resistor... does it matter... first project ... confussed to say the least thanks

Topic by laltec   |  last reply


Instructable on electroplated circuit boards?

I managed to plate a copper trace onto piece of acryllic today, to test out a process for easily and cheaply making (and possibly editing/repairing) custom PCBs. The adhesion appears to be good for surface preparation used so far, and a nice thick track has formed. So, would it be worth uploading an instructable once the process has been refined a little (or enough to make simple boards properly)? Any questions, feedback or comments would be appreciated.

Topic by The Skinnerz   |  last reply


Arduino Bluetooth to Visual Forms

Hey folks I hav a problem: I am trying to make a GUI in visual forms which displays Data received from an Arduino via Arduino sent with a HC-06 Blutooth module, the data is a 10 cell integer array which should be displayed in 10 textboxes. my problem is how do I retrieve the data from the computer's bluetooth in Visual Forms/Studio. thank you for your help

Topic by Red-Fox   |  last reply


Arduino Bluetooth to Visual Forms

He folks I have a problem I am trying to send data with my arduino via a hc-06 bluetooth module to my pc and display the data with visal forms, my problem is how do I get the data into Visual studio/forms? the data is a 10 cell integer array wich should be displayed as 10 textboxes. or is there a better software to create a GUI thank you in advance

Topic by Red-Fox   |  last reply


i need line follow code .it work for 5 sensor

I am mechlogy . i need code for arduino i am using 5 sensor code . please provide me workable code.i need code for ln987n and 5 sensor strip

Topic by ShaidK   |  last reply


Battery powered 120V light bulb

I'm trying to build a steam-punk costume and wanted to use a motorcycle battery to power several edison squirrel cage style bulbs. Fortunately these blubs look better if they are dimmed, but what I'm having a problem with is a schematic and what type of transformer to use.

Topic by Deepeyes   |  last reply


Photos

I recently had a laminate photo collage placemat made. I want to add another photo. How can it be done? Should I laminate the new photo and glue it? What kind of glue? Can I glue the photo and re-laminate the whole thing again? Thanks

Topic by impaula 


Arduino multiple if statements

Hi, Thank you in advance for any feedback for my question. I made a XY plotter machine that I want to control with a joystick. The joystick has 4 momentary pushbuttons. One for up, down, left, right. I want the up and down to control one motor (or x axis), forward and backwards, and the left and right to control the second motor (y axis), forwards and backwards. I am using an Arduino UNO with Motor shield. I have all of the wiring part sorted out, but I am having trouble with my code. The problem is when I push forwards, the motor keeps going forward even when I stop pushing the button. I would like it to stop when I stop pushing the button. I am not too familiar with programming. Here is the code I am using: //Channel A or X Axis int upPinX = 2; int downPinX = 4; int forwardX = 0; int reverseX = 0; //Channel B or Y Axis int upPinY = 5; int downPinY = 6; int forwardY = 0; int reverseY = 0; void setup() {     //Setup Channel A or X Axis pinMode(12, OUTPUT); //Initiates Motor Channel A pin pinMode(9, OUTPUT); //Initiates Brake Channel A pin pinMode(upPinX, INPUT); //Motor A forward pushbutton pinMode(downPinX, INPUT); //Motor A backward pushbutton //Setup Channel B or Y Axis pinMode(13, OUTPUT); //Initiates Motor Channel A pin pinMode(8, OUTPUT); //Initiates Brake Channel A pin pinMode(upPinY, INPUT); //Motor A forward pushbutton pinMode(downPinY, INPUT); //Motor A backward pushbutton } void loop(){ forwardX = digitalRead(upPinX); reverseX = digitalRead(downPinX); forwardY = digitalRead(upPinY); reverseY = digitalRead(downPinY); if (forwardX == LOW) { digitalWrite(12, HIGH); //Establishes forward direction of Channel A digitalWrite(9, LOW); //Disengage the Brake for Channel A analogWrite(3, 1023); //Spins the motor on Channel A at full speed } if (reverseX == LOW) {   digitalWrite(12, LOW); //Establishes forward direction of Channel A digitalWrite(9, LOW); //Disengage the Brake for Channel A analogWrite(3, 1023); //Spins the motor on Channel A at full speed } if (forwardY == LOW) { digitalWrite(13, HIGH); //Establishes forward direction of Channel A digitalWrite(8, LOW); //Disengage the Brake for Channel A analogWrite(11, 1023); //Spins the motor on Channel A at full speed } if (reverseY == LOW) {   digitalWrite(13, LOW); //Establishes forward direction of Channel A digitalWrite(8, LOW); //Disengage the Brake for Channel A analogWrite(11, 1023); //Spins the motor on Channel A at full speed } else {   digitalWrite(9, HIGH); //Eengage the Brake for Channel A digitalWrite(8, HIGH); //Engage the break for Channel B } } - Also perhaps someone could let me know how I can insert code in one of those code boxes? Thanks,

Topic by toedip   |  last reply


Can Forums and Answers sections of site be added to mobile apps?

I frequent Instructuables daily through android app on phone and tablet.  Would it be possible to add links to the Answers and Forums areas of the site to the app?  Hate that I need to tether myself to a desktop browser or struggle through a phone browser to use these great features of the site.

Topic by DiyWaterDog   |  last reply


How to connect a physical pushbutton to a display to trigger an animation.

I'm trying to figure out how I would set up a physical pushbutton so as to trigger an animation once pushed.  The programming language I'm using is processing, and the content would be played on a 32" screen.  So I'm trying to figure out what type of hardware I would need (circuit boards, pushbuttons..etc) in order for this to work.  Thank you in advance to anyone that offers some advice.  P.S. I also have little knowledge in programming this is a project so I can become more familiar with it. Thanks!! 

Topic by SarahinaB   |  last reply


Arduino servos move to music

Hi, so I'm new to arduino and I'm wanting to link arduino to processing. I then want to be able to make servos move to the beat of music that i have loaded on to processing using the computer as a network but I can't seem to find much info anywhere else and was hoping that someone could enlighten me on the process that i should be taking or able to help in anyway would be much appreciated. Thanks  

Topic by TianL4   |  last reply


Mobile charger from wind/air like windmill

Hi All, I want to make mobile charger with wind power like when i am bike/car/public transport at 60km/hr, i should able to charge my mobile. power genrated should be 5 volt at 2 amp. Could you provide me idea to construct one?

Topic by vindude5   |  last reply


Dielectric

Hello, For research purposes I need dielectric material with dielectric strength of a few tens or hundreds of voltages per millimeter and dielectric constant > 10 or > 100. I found on Internet information for a few really good materials: Material Dielectric Constant (K) BaSrTiO3 (BST)   800-1,000 Pb(Mg,Nb)O3 (PMN)  3,000 LiSiNiO (LSNO) 12,000 PbFeNO3 (PFN) 9,000-40,000 BaTiO3 (BTO) 2,000-300,000 CaCu3Ti4O12 (CCTO)   700-1,000,000 I tried to find manufacturers or suppliers of such materials but it turns out this to be very difficult. Can anyone help me with some information? Thanks!

Topic by paveltashev   |  last reply


which IC does sonic screwdriver's circuit use?

I want make a screwdriver but dont want spand 10 pounds to buy a new one and take it apart for a circuit, i want make it under 2$, which IC does they use in the toy? 555 timer? can provide organial circuit desgin? thanks alot

Topic by EthanY   |  last reply


Sound wave heart beat detection

I love to graph things. Everything from outside temperature to server room temperature to the number of users on the network to my weight.I just read an article in Make magazine about DIY ECGs, and it got me thinking.. i want to graph more things about my body :)Would a microphone embedded in the bed be able to pick up the heart beats and calculate the BPM? This way I could graph development in resting heart rate over time. The microphone would pick up lots of noise from the person moving around etc.. but that doesn't mather. It only needs to get a few clean heart beats in order to calculate the bpm, right?What hardware and software would be suitable to create something like this?Any ideas?Yeah, of course there are other more traditional ways of measuring heart beat.. but I'm to lazy to do that.. I'd rather spend some time making a fully automagickal system.

Topic by chr   |  last reply


Bluetooth adapter for car audio

Dear all, I have a Skoda audio system integrated into my Skoda which has a cd reader plus a cd changer, but  only a CD button(no AUX available). I would like to stick inside the audio system a Bluetooth receiver so I can listen to music stored in my phone. The goal is to solder a Bluetooth receiver to the audio system without loosing the cd functionality. On top of that I would like to be able to change from one source to the other without having to use an external button like a 3PDT switch. Thanks in advance, Pedro

Topic by pcardoso73 


How would I make a sensor sense motion coming at me from behind while I'm moving forward?

I'm trying to make a small sensor that would detect a large object coming at me from behind at about 60mph while I'm moving forward at around 7mph. What kind of sensor would I use? I looked up the different types and I found Passive/active infrared, optic-based, piezoelectric, and ultrasonic. I tried to figure it out myself and my best guess is ultrasonic? Like what cars use to detect deer, they use "ultrasonic airflow sensors". Ideally the sensor would beep and get louder or faster as the object approaches. Would I use an arduino? I'm very new at this :/ Thanks for any help!

Topic by arrowstation   |  last reply


Arduino capacitive touch sensor help

So I have been messing around with the Arduino Capsense library with the immensely helpful guide; https://www.instructables.com/id/How-To-Use-Touch-Sensors-With-Arduino/  (many thanks to DangerousTim!)   using the code provided, i managed to get a relay to operate with a sensor.  It worked great and I was able to adjust the distance and sensitivity.  But when i tried adding another sensor and relay, it stopped working.  I've been trying to isolate the problem for a while now and have gotten nowhere.  I'm hoping someone can help me, here's the original code for the single sensor and relay; #include #include                                           //change '42' to any desired pin... long time = 0; int state = HIGH; boolean yes; boolean previous = false; int debounce = 200; CapacitiveSensor   cs_4_2 = CapacitiveSensor(4,2);  // To add more sensors... //CapacitiveSensor   cs_4_6 = CapacitiveSensor(4,6);        // 10M resistor between pins 4 & 6, pin 6 is sensor pin, add a wire and or foil //CapacitiveSensor   cs_4_8 = CapacitiveSensor(4,8);        // 10M resistor between pins 4 & 8, pin 8 is sensor pin, add a wire and or foil void setup()                    {    cs_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF);    pinMode(13, OUTPUT);   } void loop()                    {     long total1 =  cs_4_2.capacitiveSensor(30);            if (total1 > 60){yes = true;}     else {yes = false;}            // to toggle the state of state         if(yes == true && previous  == false && millis() - time>debounce){              if(state == LOW){          state = HIGH; }     else state = LOW;     time = millis();     }                     digitalWrite(13, state);            previous = yes;                 delay(10); } and here's the code for the two sensors and relays #include int led = 13;     int led2 = 12;    long time = 0; int state = HIGH; long time2 = 0; int state2 = HIGH; boolean yes; boolean previous = false; boolean yes2; boolean previous2 = false; int debounce = 200; CapacitiveSensor   cs_4_2 = CapacitiveSensor(4,2);        // 10M resistor between pins 4 & 2, pin 2 is sensor pin, add a wire and or foil if desired CapacitiveSensor   cs_5_7 = CapacitiveSensor(4,6);        void setup()                    {    cs_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF);    cs_5_7.set_CS_AutocaL_Millis(0xFFFFFFFF);  //Calibrate the sensor...    pinMode(led, OUTPUT);    pinMode(led2, OUTPUT); } void loop()                    {     int total1 =  cs_4_2.capacitiveSensor(30);     Serial.println(total1);     int total2 =  cs_5_7.capacitiveSensor(30);                     if (total1 > 60){yes = true;}     else {yes = false;}    if (total2 > 60){yes2 = true;}     else {yes2 = false;}           // to toggle the state of state     if(yes == true && previous  == false && millis() - time>debounce){                    if(state == LOW){          state = HIGH;        }        else          state = LOW;          time = millis();      }                          if(yes2 == true && previous2  == false && millis() - time2>debounce){                   if(state2 == LOW){          state2 = HIGH;        }        else          state2 = LOW;            time2 = millis();            }                 digitalWrite(led, state);       previous = yes;       digitalWrite(led2, state2);       previous2 = yes2;                  delay(10); } Any suggestions are always helpful.

Topic by dudes   |  last reply


Build a capacitor (proper dielectric)

Hi there, I need dielectric with very high "Dielectric Strength" (a few 10s or 100s of kilo volts per mm) and also high "Dielectric Constant". Can anyone suggest me one? I would like to build a compact capacitor with high capacity and I need advice how to do it. I would be happy if someone can help me and for that purpose I will describe what I need: - The capacitor must be "Parallel Plate Capacitor". - The capacitor must be very thin with small distance between the two plates. - The dielectric must have very high "Dielectric Strength" (a few 10s or 100s of kilo volts per mm) and also high "Dielectric Constant". - The capacitor will be connected to a DC current circuit which purpose is to charge the capacitor and to keep its charge sustainable in time. - The capacity of the capacitor must be a few micro Farads. Taking into account the above, there a few important questions (correct me if I am wrong): - What dielectric to use and where can I buy it? - Is the building of such capacitor achievable in home environment or there are manufacturers who can do it for me? - Is there anything important for the building of the capacitor which I have missed to mention? Thanks a lot! ;)

Topic by paveltashev   |  last reply


5x7 dot matrix display

Hi, I have a lot of dot matrix display 5x7 model LTP-2157AE i want use it but i don't know how do it, the product is this: http://datasheet.octopart.com/LTP-2157AE-Lite-On-datasheet-7274635.pdf Can youhelp me??

Topic by PDF laboratory   |  last reply


use a landline telephone, speakers, a mic, and a computer to go online with dial-up

Would it be possible to use a landline telephone, a computer with speakers and a microphone, and a software program to connect to the internet with dial-up? there are multiple free dial-up numbers available, so if I called with the phone, and used the computer to emulate an analog modem and listen to the response with the microphone, would I be able to get online? if so, does anything like this already exist?

Topic by tyeverett4949   |  last reply


Reading a 16x2 LCD screen

Dear Techfreaks, I have a rather technical question for you guys. I have a big, company-suited coffee machine which I'd like to mod, to be internet connected. My idea is to read the LCD screen of the machine, by intercepting the wires, and interpreting the signals with a microcontroller. I'd need to read the data, and convert it into ASCII, so I can drop them on a website, and in fact have a (sort of live) view of the LCD.  The used LCD is a standard 16x2, 16-pin LCD. Does anyone have any experience with doing this? Or any tips? I couldn't find a project online which wanted to do the same thing as I did. Thanks in Advance, Willem. 

Topic by WillemB14   |  last reply


Multiple LED Bar Scoreboard

Hi everyone, Me and a friend of mine would to make a scoreboard which can display the score of around 70 different people. The way we would like to do this is by making 70 individual led strips which represents a person. Each strip has to contain about 100 leds (so the maximum score is 100). We would like to be able to set each persons score individually from anywhere between 0-100. Preferably with as little knobs as possible.  What do you guys think is the easiest and cheapest way of doing this?  We were thinking about a system with a arduino or some kind of controller and a chain of LED Bar Graphs as shown in the link below. http://i01.i.aliimg.com/photo/v57/241783705/LED_bar_graph_display.jpg We are not that experienced with electrical components so we would like to have some help with that!   Looking forward to hear some of your ideas! 

Topic by TDDG   |  last reply


Circuit Design Help

Trying to build a simple circuit to power a small pump while the sun is out. Here are the specifics: Solar Panel (60 cell mono panel) Open circuit voltage 36.4V DC, Short circuit current 7.96A. Pump 12 V DC, 9A max Using E=IR ,  R=E/I, (36.4-12)/7.96 =  3 ohms Power = V(sq)/R = 24.4/3 =198 watts  I purchased a resistor that meets these requirements and hooked everything in series. (Solar panel lead to resistor, resistor to pump, and pump to other solar panel lead. The pump does not turn on when the panel is in the sunlight. I measure the voltage coming out of the panel and it is within specification. I also tested the pump by hooking it up to a car battery and it works fine. Any ideas what I am doing wrong? thanks!

Topic by OMGIMDUMB   |  last reply


High Voltage Flyback Transformer Pinout HELP!

I pulled out a flyback HV transformer from a CRT television set (I DO know of the dangers involved, and I'm VERY careful to discharge all caps and to short out the flyback).  But the problems is, I have a FB Samsung C31113D.  Very hard to find schematics or specs on.  Rather than fiddling with which pins do what (via battery and multimeter-which I guess I could do), does anyone know of a site that offers pintout schematics for different manufacturers?  I'm anxious to begin my project on building a Jacob's Ladder.  But without knowing which pins do what, I refuse to tinker.  My life is just too important. Is there anyone who may be able to help me out here?  Perhaps checking each pin with a battery is the only way to go, but I would like to avoid that if possible.  Also, what waveform does the FB  Transformer put out?  I've heard square wave, and I've heard D.C.  The only thing I have definitely heard is that sine waves tend to result in smoke from the FB. Thank you!

Topic by huck alexander   |  last reply


Reading Electric Meter with Raspberry Pi

We have a meter outside of a building which displays how much energy the building produces (Solar Power) and pumps back onto the grid, how much the building uses from the grid, and the difference. Every day we record these numbers, and enter them into an excel spreadsheet, so we know exactly what the efficiency is of said building. The issue is, is that this building is empty for most of the week, and driving to and from the building costs time and money. So, the idea is that we have a Raspberry Pi connected to a camera photograph these numbers, and send them to us via email. How would you have the Pi take pictures? Specifically, what camera would you use? The screen is a ~3cm x 12cm LCD display (Similar to an alarm clock display, no colors) The clearance inside the box is about 10-15cm from the screen. The box itself is transparent, but we'd like to keep the camera inside the box, as the plastic isn't 100% clear (weathering), and it would also look more professional.  The box is waterproof, but not moisture proof, so it would need to be outdoor rated. Or is there some type of device we can put over the screen, and then have it copy what the screen displays? The screen/meter itself cannot be tampered with, as it belongs to the electric company.  This camera/device needs to be able to be sourced in Europe, and would be nice if it wasn't too expensive. Semi off topic: Would it be possible for the Pi to somehow analyse the images, and convert the numbers in the pictures to text?  Taking it one step further, would it be possible to have it automatically enter these numbers into a spreadsheet? This display cycles through about 10 different "screens", of which only 3 are needed. Could the camera be used as a motion detector, and when the numbers change, it takes a picture? This would be repeated 10 times, so that every screen would be captured, and then the needed images would then be sorted out, manually or automatically. If any more information is needed, just ask. Thanks!

Topic by RocketPenguin   |  last reply


Tp4056 and 18650 build

​I'm planing to build a battery pack this summer and i was wondering if this setup could work. The tp4056 boards are really cheap and I've got a few lipos around I want to make a use of it. My goal is 3s2p or 4s2p with one board per lipo cell (even  7p is of interest, but that is another build). Now I was thinking wiring from Vout on the board to a motherboard connector (something with a lot of connectors)  so that I can disconnect the entire bank for charging. Take a look at the picture, it is supposed to be a 3s pack, but I'm not sure if it will work. When charging =NO load and when load = no charging. Tp4056 have a built in protection circuit why I would like to use those. I would appreciate your help on this. What I know about the board is that Batt+ and Vout+ are same, but Batt- and Vout- are separated by a mossfet that protects the battery. And of course 3s lipos batteries do not sum up to 12V exactly, that is not the issue here. Question is if this setup would work, i.e. When charged, I can connect them in series and the output is ~12V or I fry the circuit/batteries/both!?

Topic by GoranM6 


arduino about IR sensor source code

Hi, i have no idea how to program the source code, which is when IR sensor detected something, step or dc motor would spin forward, and stop.     detected it again, the motor would back spin.   please help me

Topic by 승주권 


solar garden light

I would like to make a 3w solar led garden light to illuminate small tree. I was going to use an 18V 5W solar panel (Peak Voltage: 17.2V Peak current: 0.29A Open circuit voltage: 21.6V Short circuit current: 0.33A) to charge a 12v battery (Capacity : 4800mAh Rechargeable Li-on battery Input voltage : 12.6V Output voltage : 10.8~12.6 DC Output current : 1 - 2.4A) . I have found a charge controller which I think will do what I want (3A 6v/12v PWM solar panel light controller battery charge regulator http://www.banggood.com/3A-6V-12V-P...ry-Charge-Regulator-Intelligent-p-997571.html) The led I was going to use is 3W Voltage: 3.4-3.6V current: 600MA. I know I will need a voltage regulator to get me to the led forward voltage, but other than that does this look possible? Would an led driver be required? If there are any parts which someone would advise changing I am very happy to take advice, any help very gratefully appreciated.

Topic by earton   |  last reply


Automatic Blind Opener Advice

Hi, I am thinking of putting together something that will able to automatically open and close my blinds as the darkness outside dictates. Ideally, I am hoping to attach the opening/closing pole to a DC Motor, which would be controlled by a light sensor. I was also toying with the idea of powering the system with a rechargeable 9V battery that could be topped up with a small solar panel attached to the window. Is this idea doable and, if so, any advice on parts and putting it together would be very much appreciated.

Topic by elsmandino   |  last reply


bluetooth 4 transmitter to headphone latency reduction

Hey everyone! i'm seeking some advice about a system i've been trying to work out - a bluetooth audio headset from a PA system for vocal monitoring during band rehearsals. currently i'm running microphone -> PA -> bluetooth 4.0 AD2P compatible audio transmitter -> powerbeats bluetooth 4.2 headphones the connection is working fine, the only issue is latency between microphone and headphones (approximately half a second), which makes it very difficult to use as a monitor as i require very minimal latency to hear my voice in synchronisation with the rest of the band. a few questions; does bluetooth simply have an unavoidable lag due to data compression? is it possible for me to hack the bluetooth transmitter in some way to increase the rate of compression/transmission? what would you recommend as a cheap substitute in the event that nothing can be done? thanks very in much in advance, Austin

Topic by totemgoat 


sensors microcontrollers

Hiya guys is there anyone that can guide me to finding an instructable that deals with interaction in remote places using a micro-controller. For instance people in 2 different locations in the world, want to engage or enhance social bond or interaction by using a motion or proximity sensor and internet of things for instance triggering a sound or an led light that can be sensed in a remote location. So one location motion is detected and the other location this detection can also be seen, if that makes sense? For instance similar to this kind of project  http://goodnightlamp.com/ Could this be done? Thanks

Topic by Snowcoat   |  last reply


Hollow shafted potentiometer?

Hi everyone,  I have a project I'm working on which has two halves that are connected using a potentiometer as the axis, resulting in the two being able to twist, changing the resistance of the potentiometer.  The problem I have is that the battery is in one half and the circuit is in the other half.  I have to somehow get the power to the circuit, but still have the pieces still be able to rotate.  I can't have the wires just sticking out of the side because it has to twist, and that would look horrible.  My first thought was to drill a small hole through the shaft of the potentiometer, so that I could run the wires through that, but when I tried to do that, it turned out to be a lot harder than I expected and I now have a busted potentiometer.  I would really like to avoid slip rings of any kind, as they would be exposed to the elements.  Does anyone have any ideas, or any advice on how to drill a nice hole through a steel rod lengthwise?  Ideally I would drill the hole, but if that's too difficult, I'll try whatever. Thanks ~Dudes

Topic by dudes   |  last reply


Mass Produced Ideas

My CNC machine is almost done and a vacuum form machine should be really easy to make (1 or 2 days). I've always wanted to mass produce something, so does anybody have any ideas for a cool electronics device that they would want to buy? I'm going to make everything surface mounted. If anybody has any really good ideas then PM or post here, maybe we can even reach a percentage agreement.

Topic by guyfrom7up   |  last reply


measuring my cat's activity

Hi guys, I'm trying to create a little gadget to measure my cat's activity throughout the day by measuring its steps and sleep. I can attach a regular fitness band around its neck but I've got no clue as to the algorithm to go along with it since cats obviously don't move the same way our wrist or arm would. Any ideas? Thanks for the help!

Topic by Juan FelipeT   |  last reply


Help needed circuit components with different voltage

Hey, I have a circuit with different voltage components. How would I make all the components run on one battery?

Topic by xpalix   |  last reply


I want to make a power factor meter using arduino which can also show Real,Apparent and reactive power.

I want to make a power factor meter using arduino which can also show Real,Apparent and reactive power.

Topic by KaroonjharN 


Hacking famous brand devices

Hi, I have spend a lot of time hacking some scanner CCD sensor from different brand of scanner on the last few weeks to build a touch screen. My idea was to make a database on the different PIN of the CCD of several brand of scanner to help people building their own. It's not always  that easy to play with an oscilloscope to reverse engineer those. But I was a bit hesitating on posting brand name like HP or CANON and explain how to crack the sensors. I wasn't sure if I could have some problem... Any ideas? Thanks

Topic by jeanotP1314   |  last reply


3v Relay Module and PIR sensor circuit troubleshoot

​Looking for help on my project.  See image.  Testing before connecting to high voltage device.  Using a 3v relay triiggered by the PIR signal.  As you see wired now, There is no ground wire coming from PIR.  The circuit would not trigger relay with a ground wire to the PIR.  When this does trigger I noticed on the relay that the LED would not go completely off.  So I check to find that when relay turns "off"  the PIR is still sending 2.8 volts to the relay.  Not enough to trigger the relay, but enough to show power through the LED.  Obviously something wrong here where the PIR or Relay are still drawing power.  Can you help?

Topic by DiyWaterDog   |  last reply


Identify easily Russian letters (on vintage electronic tubes for instance) and a lot of other letters

((I wanted to post that as an instructable but indeed it's not really a project so as seamster said, it belongs to the forum, I hope it will be useful ;) )) I like symbols and letters and alphabets a lot ! [bla bla bla if you want to read all the stuff I was saying: https://www.zerobin.net/?94233ecec289eaf1#h/8pT8cAlxplvQJNn3ql9K8T8PBa36e13btxF40yu/Q=] When I'm a bit lost understanding something (might be a word, an acronym or some letters I'd like to understand how they sound). I go to translate.google.com (I think and hope there are others services, if you know some alternatives, please post, I'd love to see the alternatives) and I choose the language I'd like to see the keyboard of. Then I press the virtual keyboard button on the base of the input box to make a virtual keyboard appear, this virtual keyboard contains the disposition and letters from the language I chose, may it be Russian, Greek, Yiddish, Khmer (Cambodge), Corean or other. Sadly there is no available Japanese or Chinese keyboards available now, which is a shame :'( That's all for today/night and I hope it might be useful to some people PS: If you have any ideas on what I could do out of those фэу-35 scintillator tubes, please post ;)

Topic by nazmo76 


Seat belt fastened circuit

I have designed a circuit the intent of which is to control the seat belt fastened light on the dash.  There are two switches.  1. A pressure switch that closes when someone is in the seat.  2. A Reed switch that closes when the seat belt latch is latched.   Each works correctly separately.  I am using a standard 12V automotive relay to control the light, as below.  Let's just look at one side. 1. When the ignition on the 12V wire connects to the two leads, i.e., the pressure switch and the reed switch. 2. When someone sits in the seat the pressure switch closes and the dash light, which is connected to the relay at 30 and 87A comes on (relay not activated).  3. When the seat belt is latched, the reed switch closes, the relay switches and the current between 30 and 87A turns off. Diodes are introduced in the circuit as shown in the diagram.  The problem is that is does not work correctly.  Sit in the seat and the light comes on.  Buckle the latch but the light does not go off. There is still 12V between 87A and 30, but I don't know why.  I also tried putting a diode between 85 and 86 (pointing towards 86) but that did not help.  Suggestions please.

Topic by DaleR18 


Batch File Help...

Hi guys, i think this might be a bit of a nooby question but here goes: I have made a batch file that lets you add a password to a file, here is the problem, i would like to make the password so when you type it, it will show "****" or something to use to hide the password.Is there anyway of doing this,if so can you please tell me. Thanks :P Oh and here is the link to the source code: http://pastebin.com/EAiNvzz5

Topic by Petzl11   |  last reply


The electronics for powering a pump via solar power

So I've been tossing around the idea of making a automated garden that uses solar panels, much inspired by a vermiponics instructable I saw but I have some questions of theory and practice I'd like help with before I go into it. I've worked with simple electronics and have a fairly good grasp on the theory but nothing quite this complex or with components I'm not familiar with, so I'm looking for advice. 1) Solar panels must need something like a capacitor or battery to store the energy for the motor to use, and how would I get this reservoir to trigger at a high enough voltage so that the motor can actually spin and I don't just end up with a motor charging a battery that is discharging across a motor at a low enough current that it doesn't spin. 2) preventing the battery from discharging back into the panel, I assume one would use a diode for this but I'm curious if there's anything additional that is required 3) If I wanted to try adding further automation by adding an arduino with a mess of sensors, would powering the arduino from an additional battery charged by the same panel work (I assume this would slow down the charging of the motor's battery). 4)  Safety features to implement so I don't do things like overcharge the batteries/ suggestions encouraged. The arduino is currently gravy for the project, worst comes to worst I can set up some simple level switches.

Topic by squirrelchaser   |  last reply


Turn circuit on when another is broken?

I am having a delema on how I should have my preamp that I am assembling turn on. I don't want to use a toggle switch or anything, because I always forget to turn it off, and I end up draining the battery. So, I was thinking of having some sort of system that involves turning the preamp on when a 1/4 audio cable is plugged into the jack. However, I don't want to use the common method, having ground and the second pin shorted by the barrel of the audio cable (jack plug switch is the only name I can find associated with it...) Thing is, some of the cables that will be plugged into it aren't mono, so it wouldn't work. In fact, if I plugged my headphones into it, it would run 9v through one of the drivers... Don't want to do that. I noticed the jack I purchased has six pins. Three for audio, and three that connect to the other three ONLY WHEN NOTHING IS PLUGGED IN. When something is plugged in, the three metal contacts are lifted off of the other three pins. Since this device will only be mono, I was planning on connecting the left and the right together. This would mean, that when nothing is plugged in, the other set of pins (that aren't connected to anything when something is plugged in) would be connected, but when something is plugged in, the circuit would be broken. So, is it possible to use those two pins as a switch? Thing is, I need it the other way around: when the circuit is closed, the amp is off. When the circuit is open, the amp is on. How would I invert it? And what gate is it called? Thanks! EDIT: A NOT gate is what I am looking for. Is there any simple way of making one, for such a situation? The power supply is 9v, and it would be switching it on and off.

Topic by RocketPenguin   |  last reply


Reading 12 rows of data from an SD card every minute and storing the data into Arrays using Gboard pro Arduino

Hi, I am working on a project that measures temperature and current, store it on an SD card (csv file) and send them to a website. I decided to sample the signals every 5 seconds and store the data to the SD card using time interrupt (TimerOne). My plan is to sample and store data for 1 minute and then read the sampled data from the SD card and store them into 2 Arrays i.e Array1 for temperature and Array2 for the current and send the data to the website. Thus far I have managed to sample and store the data using the time interrupt. I also included a count variable in the interrupt subroutine so as to know how many times the interrupt has occurred. Since I am sampling and storing the data every 5 seconds and I want to read the data stored in the SD card every minute, so when count = 12 I would like to read  the last 12 readings (24 since its current and temperature ) and store them into 2 Arrays.   The problem I have is that I do not know how to read the data from the SD card and store them into two Arrays and would like your help. Note: the Reading of the SD card will not be in the Interrupt subroutine Any help or suggestions will be highly appreciated. Thanks Muundu

Topic by muundu   |  last reply


Creating a Cell Phone (Kangaroo PC + 4G LTE module + LCD Touchscreen)

Good afternoon, all! As the title sums up, I am looking at the Kangaroo PC [1], which is a $99 battery-powered pocket PC, about the size of a cell-phone, with a tablet processor and a full Windows 10 OS, and I'm asking myself one question. Why is this not a cell phone yet?! Basically, I want to install an LCD touchscreen, a 4G LTE module, and some software. This project is similar to Raspberry Pi cell phones, in the sense that it will be DIY, and the new Microsoft Lumia, in the sense that it hooks up to a monitor for desktop. Does anybody have any advice, or know what direction to point me in? I am specifically asking for help with the 4G LTE module and maybe the LCD Touchscreen. I'm not sure what to get, where to get them, or how to install them. (I've searched and found miniPCIe and m.2 modules, so far.) Thank you!! [1]: (Newegg) http://www.newegg.com/Product/Product.aspx?Item=N82E16883722001

Topic by jrs91 


Is there a difference between a 1/4 inch x 20 bolt and 1/4x2 bolt?

I'm trying to make a camera neck strap using parcord and one of these bolts.

Topic by LAPIII   |  last reply


Need Advice: Push a Button Get an Alert on Mobile Phone

Hi all, I'm attempting something "techy" for the first time and need a bit of help getting started, or deciding if this is possible. I'm trying to create something that will send an alert to a mobile phone if a button on another device is pushed. I'm fairly confident this is possible, but not sure what technology I could use to achieve this. I bought an Amazon Dash button to play with but not sure if that makes sense.  A rough idea of what I'm trying to achieve: If the Amazon Dash button is pushed and HELD for more than 5 seconds, the phone it's linked to would display an alert message or sound (preferably until the button is released). The button and the phone would be located in the same room. Does that sound feasible? What are some components/skills I would need to gather/learn for this project? Massive thanks for the help!

Topic by CoughCough   |  last reply


Need component advice/help for a instructable

I wanted to build this instructable, but it requires STM32F051 micro controller. However there's different types of 'STM32F051' micro controllers such as a T8, K8, C8, R8, V8, K6 C6, R6, etc. So does it matter which kind variant i use or will they all work the same? If it does matter, what kind do i use? Or is there an alternate micro controller that will work? Source Instructable : https://www.instructables.com/id/Market-Minder/

Topic by acadena2   |  last reply


RPi2: OSMC Terminal Issue

I am trying to make some changes to OSMC through the terminal, but there is an issue with the login portion of it. When I quit OSMC, and wait for the boot screen, I hit Esc, and it goes into the terminal. Next, the login. I enter "osmc", then its to the password. But, it refuses to let me type anything in when I get to this stage. If I hit enter, it tells me that my password is wrong and then it goes back to prompting me to login. After about 15 seconds, it just continues to boot into OSMC. Why on earth will it not let me enter a password, and how do I fix it?

Topic by Dashing Rainbow Dash