Calibrate Compass

I have compass cmps-12 and i want to use it or calibrate it with my raspberry pi 3 using python. I already check on website but im not find it how to make it work. Please anyone knows how to calibrate compass cmps using python on raspi3 i need your help. :(

Topic by alharis   |  last reply

LDR Calibration ?

I am planning to build a lumenmeter but I am not getting how to calibirate the LDR and do not have any lumen meter so if could tell the estimate lumens out of a 5w CFL or any other device might help

Question by Bot1398   |  last reply

calibrate a monitor with a web cam?

Good day be possible to calibrate a PC monitor with a webcam?

Topic by Hidalgo1977   |  last reply

Thermocouple calibration - How to

Hello,I have a few questions about the thermocouple calibration.I want to use three type R thermocouples to measure the temperature during a 3d printing process using an Arduino Uno and the max31856 amplifiers. Right now I am doing tests with K type thermocouples before we buy the R-types. It seems to work fine, it measures a room temperature of 22ºC more or less and reacts reasonably in my opinion but I would like to know if the measured temperature is the actual temperature.1. Is a calibration needed? I know the amplifiers (max31856) do some corrections automatically, but maybe an extra calibration is needed.2. If such a calibration was needed, how would I do it? For example, I will put copper in an oven and heat it and measure the temperature with my thermocouples and with a bolometer. If my thermocouples measure something different, how do I correct it? Theoretically my program transforms (via amplifiers) the measured tension difference into temperature, correcting it at the junction. How would I tell it now that it has to measure differently?3. If no calibration is needed and, as I explained in 2, my thermocouples measure something different as the bolometer, which one is the accurate? Thank you very much for your help.

Question by DiegoH57   |  last reply

Knex gun calibre!

For a while people have been calling their guns white rod shooting guns, blue rod shooting guns ect...  Which in my opinion sounds rather poor so I am starting a calibre system. Here it is...                                                                        Green rods= 1cal             White rods= 3cal             Blue rods= 6cal             Yellow rods= 12cal             Red rods= 24cal             Grey rods= 48cal                    The calibre is based on how many connectors the rods can hold.                    If this has been made before I apologise. Please tell me and I will remove it.

Topic by PotatoCoffee   |  last reply

what is meant by ESCs calibration?

I know how to calibrate ESCs on the quad-copter. Howver, I dnt understand the concept of calibration. What is meant by ESC callibrarion? what happens when we calibrate the ESCs? is it so they move synchronously or so the PWM signal reaches each ESC at the same time?

Question by Bam Boy   |  last reply

stepper motor calibration issue?

Hi, I am building a CNC using Mach3 to control it. the steppers were running fine, but then i tried to calibrate one axis. After calibration the motor no longer hauls, and instead issues a beeping sound for the duration of the run. Does anyone know what happened? Any fixes?

Question by jg156   |  last reply

there a way to calibrate an autoranging multimeter?

Hello community, I have a little problem with auto ranging multimeter Techman brand TM-107 the question is that I would like to calibrate and mark certain ranges wrong, I have intermediate level knowledge of electronics, the question is whether by changing parts that do not make their specific value would fix the problem or would have to make other method?

Question by jediknightgeorge   |  last reply

Position of gyro and iPhone during calibration?

I have a gyro and using an app on the iPhone (tilt meter).  My question may be basic. But does the gyro sit ontop of the phone, while the phone is standing up (see attached) or is the iPhone laying flat (display up) while the gyro is ontop of the phone?

Question by nmsr1196   |  last reply

Should half inch thick, high-strenth chip board stop a .177 calibre pellet?

Should half inch thick high strenth chip board stop a .177 calibre pellet with a force of 8 ft pounds and travelling at 600ft a second? I have recently made a pellet trap it is a box with a high strenth chip board guard to stope stray pellets (as seen in the pic) the box is ok but i am worried about the guard. My air rifle is a BSA metour mk6?

Question by oscarthompson   |  last reply

Roger Boisjoly dies at 73; engineer tried to halt Challenger launch

The death of an Engineer of the highest calibre.,0,2248999.story

Topic by steveastrouk   |  last reply



Question by orangeroom-1957   |  last reply

How do i attach a scope to a gun?

The scope is the back thing besides the pump and it needs to go on to of the PVC somewhat lifted, whats the best way to do it. Some minor adjustablity would be nice so I could calibrate it time to time.

Topic by sleepwalker0   |  last reply


Hi, i a video in youtube that explains how to make a multitouch screen with a wii remote and i was wondering if you can make the same but with an ir webcam/video camera. [and i have a probably stupid question but how to make a 4 point calibration in windows vista...} {Sorry for the bad english but I'm portuguese}

Topic by TTSDA   |  last reply

assemble a ultimaker for me please

Hello guys  I am looking for someone who can assemble and calibrate a ultimaker 3d printer for me  living in canada  i am willing to pay for the service  please contact me at  if you are interested to take this project up  Thanks for looking and have a great day ahead! Yours Respectfully Avi

Topic by avinash3ds 

Dmm model no. MAS830L not accurate

I bought multi meter on line recently. But it I think cannot measure electronic component accurately. Specification as below 1.model no. MAS830L 2.Brand.MASTECH I measure new battery of 9 V with thus multi meter. But reading is 10.76 V which not correct. So what can I do with this dmm.? 0r how can we calibrate it.

Question by SangpoSangpo   |  last reply

Xaxxon Oculus Prime

I have bought and built a OculusPrime, While the unit is sound i have had problems with LIPO batteries charging wrong even though it has a balance feature , I have also had calibration and program (python) issues where it will work for a day or two then out of nowhere it stops working Does anyone know or have one of these units that could send some much needed help?

Topic by cybersarg 

Testing a Cheap Multimeter

It's been years since I had an expensive meter. These days, I have meters in the $5 to $20 range. Usually they're accurate enough for my purposes, but what if I want to be really certain? Is there a way without a pricey meter to test em?  Perhaps calibrate the meter by checking v  coming out of a v regultor. Would that be accurate? Perhaps the 7805 regulator which is supposed to output 5v.  y?n? M?

Topic by Toga_Dan   |  last reply

Why is my quadcopter toppling when i try to fly it?

I built a quad copter. I have done all the calibrations correctly (accel, compass, rc, esc). When I arm the drone, motors and propellers are spinning. But when i give more throttle to try to hover it, it doesnt fly upward steadily. Instead it lifts backwards and falls. Why is this happening? Should I change some PID setting?

Question by prash319   |  last reply

Help for realising a linefollower tankbot

Hello, I want to realize a linefollowing tank bot. I got this following parts: - Arduino Mega 2560 - Arduino MotorShield Rev03 - Pololu QTR-8RC Array - Pololu RP5 Tankchassis (6V DC Motors) Now all parts are together and the code must be completed. Therefore I found a really nice PID-based tutorial for linefollower: I create a program, but after calibrating the sensors, the bot doesn't drive on the line. It makes no sense were it drives. Most time it do 90° turns and so on. Do you find a better solution for my code? [code] #include #include   /////////////////////////// // define constants   // /////////////////////////// #define AUTO_CALIB  false      // Autokalibrierung aktivieren #define DEBUG_ENABLE   true               // false=keine Serial Ausgaben #define NUM_SENSORS    8                  // Anzahl der verwendeten Sensoren #define TIMEOUT        2500               // waits for 2500 microseconds for sensor outputs to go low #define EMITTER_PIN    QTR_NO_EMITTER_PIN         // Default: kein Emitterpin definiert #define MOTOR_SPEED    100               // PWM Signal 0-255 (Basismotorgeschwindigkeit) #define MOTOR_MAX_SPEED 255       // PWM Signal für Maximalgeschwindigkeit #define KP     0.2                    // KP-Wert für PID Regler #define KD     5                     // KD-Wert für PID Regler ( Beachte: Kp < Kd) #define SERVO_PIN1  11       // PWM Ausgang für Servo1 #define SERVO_PIN2  12       // PWM Ausgang für Servo2 #define CALIB_LED   13       // LED Ausgang für Kalibrierungsphase ////////////////////////// // define variables     // ////////////////////////// // Zuweisung der Sensoren 0-7 an die digitalen IO's 22-29 QTRSensorsRC qtrrc((unsigned char[]) {22, 23, 24, 25, 26, 27, 28, 29}, NUM_SENSORS, TIMEOUT, EMITTER_PIN); unsigned int sensorValues[NUM_SENSORS]; int MotorLeftSpeed=3;                  // PWM pin for speed control left int MotorRightSpeed=11;                // PWM pin for speed control right int MotorLeftDirection=12;            // digital pin for direction control left int MotorRightDirection=13;            // digital pin for direction control right int MotorLeftBrake=9;                  // digital pin for brake control left int MotorRightBrake=8;                 // digital pin for brake control right int lastError = 0; ///////////////////// // Initialisierung // ///////////////////// void setup() {     // Initialisierung verschiedner IOs   pinMode(CALIB_LED, OUTPUT);    // Definiert LED Ausgang für Kalibierungsphase       // Initialisierung linker Motor   pinMode(MotorLeftDirection, OUTPUT);      // Definiert Ausgang für den linken Motor   pinMode(MotorLeftBrake, OUTPUT);          // Definiert Bremse für den linken Motor   pinMode(MotorLeftSpeed, OUTPUT);   // Definiert Geschwindigkeitsausgang für linken Motor   // Initialisierung rechter Motor   pinMode(MotorRightDirection, OUTPUT);     // Definiert Ausgang für den rechten Motor   pinMode(MotorRightBrake, OUTPUT);         // Definiert Bremse für den rechten Motor     // Initialisierung Servo Motoren   servo1.attach(SERVO_PIN1);     // Zuweisung PWM PIN für Servo1   servo2.attach(SERVO_PIN2);     // Zuweisung PWM PIN für Servo2   if (DEBUG_ENABLE)   {    Serial.begin(9600);    Serial.print("Debug Modus aktiviert:\n");     }     delay(500);     digitalWrite(CALIB_LED, HIGH);    // turn on Arduino's LED to indicate we are in calibration mode   for (int i = 0; i < 400; i++)   // make the calibration take about 10 seconds   {     qtrrc.calibrate();           // reads all sensors 10 times at 2500 us per read (i.e. ~25 ms per call)   } delay(20);      // The 20 ms delay in the calibration code is intended to make the routine take a reasonable amount of time.     digitalWrite(CALIB_LED, LOW);     // turn off Arduino's LED to indicate we are through with calibration       if (DEBUG_ENABLE)    {    // print the calibration minimum values measured when emitters were on       for (int i = 0; i < NUM_SENSORS; i++)    {   Serial.print(qtrrc.calibratedMinimumOn[i]);   Serial.print(' ');    }    Serial.println();       // print the calibration maximum values measured when emitters were on    for (int i = 0; i < NUM_SENSORS; i++)    {   Serial.print(qtrrc.calibratedMaximumOn[i]);   Serial.print(' ');    }    Serial.println();    Serial.println();   }   delay(1000);   } /////////////////// // Main Program  // /////////////////// void loop() {   // read calibrated sensor values and obtain a measure of the line position from 0 to 5000 // To get raw sensor values, call: //; instead of unsigned int position = qtrrc.readLine(sensorValues); // Variable positon zeigt die genaue Position (0-7000) an   unsigned int position = qtrrc.readLine(sensorValues); // get calibrated readings along with the line position, refer to the QTR Sensors Arduino Library for more details on line position. int error = position - 3500;  // 3500 is the desired position   if (DEBUG_ENABLE)   {    // print the sensor values as numbers from 0 to 1000, where 0 means maximum reflectance and    // 1000 means minimum reflectance, followed by the line position    for (unsigned char i = 0; i < NUM_SENSORS; i++)    {     Serial.print(sensorValues[i]);     Serial.print('\t');    }    Serial.print(position);    // comment this line out if you are using raw values   } int motorSpeed = KP * error + KD * (error - lastError); lastError = error; int rightMotorSpeed = MOTOR_SPEED + motorSpeed; int leftMotorSpeed  = MOTOR_SPEED - motorSpeed;     if (rightMotorSpeed > MOTOR_MAX_SPEED ) rightMotorSpeed = MOTOR_MAX_SPEED;    // Verhindert dass die Maximalgeschwindigkeit überschritten wird if (leftMotorSpeed > MOTOR_MAX_SPEED ) leftMotorSpeed  = MOTOR_MAX_SPEED;    // Verhindert dass die Maximalgeschwindigkeit überschritten wird if (rightMotorSpeed < 0) rightMotorSpeed  = 0;          // Verhindert einen negativen Geschwindigkeitswert if (leftMotorSpeed < 0) leftMotorSpeed   = 0;          // Verhindert einen negativen Geschwindigkeitswert   {   // Ansteuerung der Motoren durch PID Berechnung   digitalWrite(MotorRightBrake, LOW);     // Motorbremse rechts deaktivieren   digitalWrite(MotorLeftBrake, LOW);     // Motorbremse links deaktivieren   digitalWrite(MotorRightDirection, HIGH);   // Motor rechts im Uhrzeigersinn  --> fährt vorwärts   digitalWrite(MotorLeftDirection, LOW);    // Motor links gegen den Uhrzeigersinn  --> fährt vorwärts   analogWrite(MotorRightSpeed, rightMotorSpeed);  // Motorgeschwindigkeit rechts in Abhängigkeit des PID Reglers   analogWrite(MotorLeftSpeed, leftMotorSpeed);  // Motorgeschwindigkeit links in Abhängigkeit des PID Reglers }           } [/code]

Topic by julianpe   |  last reply

Does anybody know of a Potentiometer that can be set digitaly but operate passively?

I wonder if this technology exists. Imagine the following situation: During setup/calibration I can power the circuit and "tune" my potentiometer using some type of digital interface. (e.g. I2C) However, during operation the device is fully passive and will not have a source of power. Thus, the potentiometer would need to "remember" the settings and operate passively. Currently I use standard potentiometers, but tuning them manually is way too cumbersome and not practical. Ideas?

Question by Kapiau   |  last reply


OOOOK!! So here i am with another question... My wife bought me a kindle fire three days ago. i have been tinkering around with it to see what i can do with it naturally...i then got to thinkin i wanted to put all my 'Ibles e-book downloads on it...but heres the hitch...i downloaded Calibre to convert the documents, and i am having a number of problems... Problem 1:  After converting the pdf to MOBI, and then syncing it to my Fire, i disconnect the device and test to see wether it was a successful sync (to see if technology was telling the truth as it is often fickle). Well, success it downloaded...but thats not the problem...when i look for the new e-book i just converted, i would expect to see the book's cover as it is on the 'ibles website (ie: go to the e-books page and look for the guide to paracord). what i see is not that but what you see when you click the download button on the download page (it has the cover, and the intro description of the e-book). I want to figure out how to get Calibre to convert the book to have the real cover...not the description page. Problem 2:  I want to try to download the e-pub of the guide to paracord...but when it asks to save it...i save it and then it downloads. after that i go to the file its sitting in, and magically the file is a zip file...i have NO idea what i am supposed to do with this!!! i extracted the file, and low and behold...there is a gazillion files within files (not really...its more like 50+ folders haha). i then proceeded to move the files to my Kindle Fire and then disconnected the device and BOOOM!!! nothing!! Problem 3:  when i did the conversion to MOBI in Calibre and then did the test on my Fire, i touched one of the direct links in the TOC and it zapped me straight to the beginning of the book... If anyone knows whats giong on, PLEASE HELP ME!!! And before anyone asks...*i have read the instructions to the software*

Topic by sokamiwohali   |  last reply

Need AVR debugging/help

Here's my setup, I'm building an electronic car that needs to go a predetermined distance for a contest. We get the distance right before the challenge, and then my team is going to program it into the avr. We get distance feedback via an encoder wheel and a phototransistor with IR LED. The phototransistor pulls the pin (PB0) up. Do I need a pulldown resistor? The code powers a motor through a transistor via PB4. There is a calabrate function so that we can enter the distance on top, the calabrate function will turn it into a useful number, and then the code will run. The motor runs until the calabrated number is reached. Unfortuanteley the code doesn't work. Any help, please? I'm probably not specific enough in this little paragraph, so please leave a comment if this doesn't make any sense.The target uController is the attiny13/attiny13acode (this is one of the first AVR codes i've made, with the help of other team members):#include #include #include #define mmDistance 5 // the required distance in millimeters // For the aTTiny13a/*pinout:1) PB5, RESET2) PB3, CLK3) PB44) GND5) PB0 MOSI6) PB1 MISO7) PB2 SCK8) VCC*/ // Input from encoder wheel is PB0 (physical pin 5) // Output to motor is PB4 (physical pin 3)int Calibrate(int x) // Calibrate converts distance to set{ int y; y = x+3; return y;}int main(void){ int clickDistance, setDistance, on = 0; clickDistance = 0; // clickDistance is the distance travelled so far DDRB = 0b00001000; // setting outputs and inputs 00001000 setDistance = Calibrate(mmDistance); // setDistance is set distance in clicks PORTB = 0b00001000; // turn on motor on = 1; //on tells if previous sense had button on or off while(clickDistance < setDistance) { // while loop if(PINB == 0b00000000 && on == 1) // button off, previous true { clickDistance = clickDistance+1; // increments clickDistance by 1 on = 0; } if(PINB == 0b00001000) { on = 1; } } PORTB = 0b00000000; // turn off motor _delay_ms(5000); return (0);}

Topic by guyfrom7up   |  last reply

What could I use for a depth sensor in a SeaPerch ROV? Answered

I am in the process of building a SeaPerch ROV, and I want to add a few sensors with an Arduino. I have the other ones figured out, but I can't figure out what I could use for a depth sensor. I've thought about using a pressure sensor and calibrating it to give me a rough estimate of how deep it is, but I don't think that'll work too well. So if someone has some ideas for what I could do for this, that would be quite helpful. Thanks.

Question by mbudde   |  last reply

How to convert analog MQ4 sensor output to ppm

Hi everyone,  My final year engineering involves a rover that can sense methane gas. Initially the idea was to just detect the gas as digital input but now i wanna do a bit more. I've searched all over the internet on how to convert the analog values to ppm, but couldn't understand any of it. I'd be really great-full if someone could give me the formula or the code to do this.  I don't intend on calibrating the sensor to find precise answers, just a rough picture of the ppm values is enough to begin with. Thanks a lot in advance. 

Topic by ZeeshanA27   |  last reply


Ok I've got an idea of a aarcade like gun that could be used for your everyday PC \lappy. I was thinkin that people could probably use the arcade gun for a mouse.   Instead of using it just for game etc it could used to play FPS game and even for FPS creator so instead of using your mouse it could be as if you were the character and the one who is aiming!!! I even noticed that the newer or older? guns with a slide would be cooler.

Topic by kenexinator   |  last reply

IOT Pollution monitoring HELP!?

Im torn between the two- Should I used Pi or Arduino for outdoor pollution monitoring? I have roughly a budget of $120 USD per node.  Can I use both of them together? - If pi. What do you do about battery conservation? Pushing data to a webpage recomendations? Uploading data? What sensors should I use? Ive seen someone trying to sell a single CO2 sensor for $50 USD?!? CO2, NO, CO, NO2 sensor suggestions? Ive been looking at grove Some will be battery powered. others by the mains. im going to try 3D print a case for weatherproofing.

Topic by LukeM5 

What is the advantage of PWM vs supplying variable voltage?

Friend and I are very new to electronics and we were dimming LEDs in completely different ways I think. We both defended the way we had learned to do it without really knowing why :) Any thoughts? Also, with a servo, can you do both methods as well? And is there a way to tell a servo to go to a specific "spot" on its turning radius, or is it all relative, like supply a low voltage and it will turn a little? Do you just sort of calibrate it, so you can figure out how much voltage at how much time goes a constant radial turn? Blah

Question by prismspecs   |  last reply

Can't even find link to download ebooks

I became a pro member yesterday, and the membership appears to be working correctly -- I can download full instructables including pdfs. But I'm having trouble with ebooks. When I click on "Download the ebook" I'm taken to a page that allows me to download Adobe Reader, Calibre, and the iBooks app. But I don't see links anywhere to download the actual book. (PDF is my preferred format.) I can see from this forum that many others are having similar problems, so this is clearly a frequently asked question. But I don't see a hint of an answer anywhere. Can someone please help?

Topic by rcfinn   |  last reply

Temperature sensor using LTC2984

Dear Sir, I am using following device to measure temperature accurately, According to datasheet, the eval board can show a virtual temperature output using built in thermocouple thermister, RTD etc in ADC mode ., I need to measure real temperature which they apply in Heat bath or temperature calibration set up. I dont have such set up now, could you kindly give me a way out that without those set up I could manage Thermistor ? Kindly go through the page 43-47 in this datasheet, Thanks in advance.

Topic by Hasan2015 

Arduino code not working. Super basic but I'm stuck. Help is appreciated. Answered

     So I have wrote an Arduino code for a simple Aquarium dosing pump controlled by Android and Arduino. I have a button on pin 8 and I want the button to just be a physical trigger for the dosing for calibration purposes. for whatever reason i cant seem to figure out how to do this and help would be greatly appreciated. Thanks a bunch (: (Warning: I'm far from an expert at Arduino I'm sure there is lots of ways this could be improved) //Objective: Dose aquarium with chemicals daily via bluetooth app. with the amount dosed set by potentiometer int pumpPin = 10; //to relay int ledpin = 13; //for test purposes int state = 0; int flag = 0; int Dtime = 0; //value for how long to dose int Mval = 0; //Variable that holds the value of dosing time int PumpCalPin = A0; //pin the potentiometer goes to int pumpTestPin = 8; //button to set off pump for calibration purposes int buttonPower = 9; //source of power for the button because I'm out of voltage pins void setup() {   pinMode(pumpPin, OUTPUT);   pinMode(buttonPower, OUTPUT);   digitalWrite(buttonPower, HIGH);   pinMode(pumpTestPin, INPUT);   pinMode(ledpin, OUTPUT);   digitalWrite(pumpPin, LOW);   digitalWrite(ledpin, LOW);   Serial.begin(9600); } void loop() {   int testPinVal = digitalRead(pumpTestPin);   if (testPinVal == 1) {     state = 1;     flag = 0;   }   if (Serial.available() > 0) {     state =;     flag = 0;     Mval = analogRead(PumpCalPin);     Dtime = map(Mval, 0, 990, 1000, 5000); //map the potentiometer input from 1 to 5 seconds   }   if (state == '1') {     digitalWrite(pumpPin, HIGH);     digitalWrite(ledpin, HIGH);     delay(Dtime);     digitalWrite(pumpPin, LOW);     digitalWrite(ledpin, LOW);     if (flag == 0) {       state = 0;       flag = 1;     }   } }

Question by harry88   |  last reply

How can I re-align the screen on a TI-85?

I obtained a secondhand TI-85 for a dollar today. It didn't power on, so I removed all the batteries and put a jumper across the contacts for the memory backup, which cleared the memory and reset everything to default. HOWEVER, The LCD seems to be calibrated 4 pixels off. When anything is entered into the base screen, the left four pixels are off the display, leaving the fifth column of the character to be nudged up against the left side of the display. When I graph something, however, the display is centered. Any ideas what could be causing this? A second "Reset All" didn't help. I'm a TI-83 user, so I'm not familiar with the TI-85 interface.

Question by CameronSS   |  last reply

Featured I'ble not showing on front page or withthe snazzy banner?

Hullo all... I received the email telling me that I am awesome... and indeed that my I'ble on Trebuchets is also of the same calibre... BUT... It doesnt appear to be showing up on the home page... nor does it have the little white diagonal banner that says 'Featured'... that my other featured I'bles have... I assumed that it was just due to updates and filters and such... but the time stamp on the email shows that I was featured at: 17 April 2010 00:17:43GMT   I show up in this link: Decided to take this to the forum as I was unsure who to email... or If its part of the new site re-vamp? Let me know Jay did no one ever learn that its not wise to mess with the person holding the siege weapon??? ;)

Topic by Biggsy   |  last reply

remote code for curtis tv?

I have a curtis LEDVD1975A-2 tv that I got for christmas. I have it hooked up with my comcast digital converter and the little remote with it. I am trying to calibrate it or whatever so I can control the power and volume of the tv with the comcast remote. The instructions for my remote say to hold the set button until the light blinks twice, then enter the 5 digit code. Well, the code the manual for the tv says is 2295. Only 4 digits. It doesnt work. Comcast does have a thing that gives you codes other people have used but none of them have worked for me yet. They say 11326 and 11531. Here is the link to the thing I am trying to use to get codes.

Question by TOCO   |  last reply

using TSOP4838 in anti-collision line follower

i want to use IR sensors with emitter part ( IR led ) - calibrated with an IC timer to give 38KHZ IR signal - mounted side by side - not face to face like the counter module - to the receiver part ( TSOP4838 ) which will turn on once something reflect the IR signal back to the receiver. [ the default is that IR signals will go straight forever without being seen by the receiver ]. I've followed the steps of a circuit using IR sensor in an object counter module it included transistors to be triggered instantly as described the problem is that it gives an instant pulse to trigger the 7-segment display. but in here i don't need it to be instant. how could i implement it to make the LED bright as long as i block the path [ not instantly ]. and to be off whenever there's no object in front of the robot

Question by superdz 

How do I wire up an arduino, keypad, display to a stepper motor?

I know the basics of how stepper motors work and I'm learning about arduino boards work. How do I connect an arduino board, number pad, and digital display to control distance a nema 23 motor travels on a geared rack? I would like to be able to enter a number on the keypad, such as 12.5, have it show up on the display and then rotate the stepper the appropriate number of steps to equal 12.5". I would assume it would require some sort of calibrate function. I'd also like to be able to use metric as an option. I want to buy some parts to get started, but there is so many different types of boards, keypads and displays, I don't know where to begin.

Question by d-porscheguy   |  last reply

Observing &quot;weather&quot; (stratospheric temp.) with cosmic rays

An article in New Scientist reports on an analysis of cosmic ray muon data from the MINOS underground detector, which correlates with "sudden" (24-hour timescale) temperature changes in the stratosphere. The original article in Geophysical Research Letters gives you a good flavor for how this kind of analysis is actually done, and written up for publication. The figure below (Figure 3 of the article) shows the beautiful correlation between the temperature (5-day running average in blue) as measured by sounding balloons, and the muon rate in MINOS (also 5-day running average, red band with uncertainties). The alignment of the two curves is obviously not known a priori. The exact numerical calibration between muon counts (red, right scale) and temperature (blue, left scale) is a fitted output of the analysis, not an input.To me, it's just kind of neat that particle physics can relate so sharply to some "real world" large-scale properties.

Topic by kelseymh   |  last reply

Arduino Code?? Answered

I have created a code for the arduino breathalyzer and I wat to confirm that will it work properly so please someone who's good with this can do this for me.And yes the code compiles successfully but will it work as expexted.It should light up some of the 7 LEDs according to how much you drink.It also has a pot to calibrate the sensor and i will be using a MQ-3 alcohol sensor. here is the code: const int analogPin = 0;    // the pin that the potentiometer is attached to const int ledCount = 7;    // the number of LEDs in the bar graph int ledPins[] = { 7,6,5,4,3,2,1 // Here we have the number of LEDs to use in the BarGraph   };   void setup() {   for (int thisLed = 0; thisLed < ledCount; thisLed++) {     pinMode(ledPins[thisLed], OUTPUT);   }} void loop() {   //This is the code to light up LED's   int sensorReading = analogRead(analogPin);   int ledLevel = map(sensorReading, 500, 1023, 0, ledCount);   for (int thisLed = 0; thisLed < ledCount; thisLed++) {     if (thisLed < ledLevel) {       digitalWrite(ledPins[thisLed], HIGH);     }     else {       digitalWrite(ledPins[thisLed], LOW);     }  }}

Question by Bot1398   |  last reply

PIC24 programming troubles?

Hi, I have been working on a board with a PIC24FJ32GA002. The board had the correct voltages on the PIC's power pins (3V). I was able to program the pic one time successfully with my PICkit3, but every subsequent attempt has resulted in the following error message: Connecting to MPLAB PICkit 3... Firmware Suite Version.....01.29.33 Firmware type..............dsPIC33F/24F/24H Target detected Device ID Revision = 3046 The following memory area(s) will be programmed: program memory: start address = 0x0, end address = 0x2bff Programming... EEData memory Address: 0 Expected Value: 0 Received Value: 0 Calibration memory Address: 0 Expected Value: 0 Received Value: 0 Failed to program device I don't think the chip is fried since it still reads the device ID, but I have no idea what's going on with the EEData error. If anyone knows anything about this, that would be greatly appreciated. Thanks in advanced.

Question by Higgs Boson   |  last reply

EyeTracking (with Wii )... !! possible?

For those who are thinking to themselves "Jonny Chung beat you to it long time ago".... Don't jump to conclusion. I'm here to use his idea and give it a little twist. (if its possible that is) So let me know if this is worth pursuing... because i'm sure someone must have thought of this already... I'm also nowhere close to being a developer... with that said lets jump into what i want to call Basically i want to use our EYES to reflect Infrared to the wiimote to calibrate the movement ... and capture it and do something cool with it...    -  steer a car in a racing game...  -  look around in a 3d environment  just by moving ur head...  -  maybe even use it as a mouse and Wink with one eye to click? im waiting for a friend of mine to find time to build me that IR LED board Jonny Chung used in one of his videos. IF anyone thinks this is something to look into, I would like to be notified.

Question by solidkundi   |  last reply

Voltage Regulator

EDIT: Anyone Interested please check below posts, this is one is obsoleteHello!I need a voltage smoother and regulator on my circuit(attached below)it is a modified shunt charge controller circuit.It converts the Tri phase alternating current to DC and feeds it into the circuit.The regulator will have to be attachable to the BATTERIES wire in the circuit.It should not consume more than 1v power on its own.My Vout to the battery currently is fluctuating.I will need the to be a stable 12v to charge the batteries. A potentiometer will have to adjust current.I will calibrate current according to my battery bank needs.Led 1 indicates 'charging' Led 2 indicates 'Dump'And Please forgive my circuit diagram design(it looks like crap)but works like gold.Also do NOT suggest huge changes to my controller for the regulator to work. Small suggestions to make it more effective,useful like change the zener diode power rating will be welcome.P.S- Its for my hydro project.Check it out at

Topic by mhkabir   |  last reply

Why my quadcopter is oscillating and crashing after taking off?

Hi guys, I am new to this multirotor domain. We are strugling with our first F450 quad. Below are the specs: 1. F450 quadcopter chassis 2. KK2.1 Flight controller. 3. FLYSKY CT6B --- 6 channel radio transmitter 4. 1400 KV Brushless motor 5. 30 amps ESC 6. Lipo battery Firstly the quad was not taking off properly. More over, after activating self level mode also, the quad is not at all stable. If we max up the throttle, then it flips in one side and crashes. Otherwise, it takes off from the ground upto 1-2 feet if we slowly increase the throttle and then oscillates and to avoid crash, we then decrease the throttle. Please see the video HERE for more reference. Please guys, really need your help in this matter. We are not able to understand exactly what is wrong with our quad. We have already calibrated our ESC's and the Accelarometer but no luck. Please help guys.

Question by RohitR66   |  last reply

Quadcopter build help? multiwii is causing motors to twitch when throttle is applied

I have been working on a large X525 quadcopter kit/ w/ multiwii SE v2.5 from amazon, and have had success with configuring the multiwii for the quadX configuration, however, when I arm it and try to take off, all 4 motors ramp up to speed but then cut out and continue ramping up, particularly one motor, whichever is the lowest. Balancing the quad on 2 legs, the quad seems to want to stabilize, but keeps tetering violently since the motors keep randomly cutting out. I have tried to calibrate the ESCs by connecting them individually directly to the CH3 (throttle) receiver, powering up the Tx with the throttle high,plugging in the LiPo battery, and after hearing the jingle, lowering the throttle back down to the lowest position and waiting for the first few beeps before I unplug the LiPo battery and moving on the the next ESC. I was looking at the multiwii outputs through the software and they were in fact jumping around like crazy but after taking the props off the amount of twitching did go down a little, but still about 10-20% deviation in the bars of the software readouts. I've also tried dismounting the multiwii from the quad to eliminate the possibility of vibration from the motors from causing the multiwii to attempt corrections to the motor. though it seems to have the same for as long as I could tell because by the time I tested this, the multiwii board touched the power distribution board causing magical smoke to be released. Oops! Now the multiwii is completely dead all but the green power light which is directly connected to power Vin. The board and all the chips appear completely fine with no damage, and there is voltage to the main ATmega328, I don't know if I should try desoldering the ATmega and buying a replacement, or suck it up and buy a new $30 board. For all I can tell, I do not see how other sensors could have failed since the the exposed through-hole headers that likely touched the distribution board are directly connected to the multiwii's analog/digital input/output pins, I suspect that is all that went bad is the ATmega chip, even though if shows no sign of burning and does not overheat with power applied. Anyway while I wait, I thought I will ask about this problem to see if it is something simple like sensors calibration. (w/o motors operating, the output appears as it should!!!)

Question by -max-   |  last reply

Connect camera to NXT?

A friend and I are currently developing a turret that has a stationary camera attached to it, and two servo motors that move the actual gun part of the turret up/down and left/right. I am using software already developed for the program, and I plan to use my NXT to run the software and act as the driver for the servo motors using some modified cables. My only problem is that since I am running the software on the NXT, I need to be able to set up the USB webcam I have so that it inputs it's data into the NXT unit. The problem is, I have no idea how to do this. I was thinking of using the standard cable the NXT comes with that has a USB end, and connecting it to the USB end of my camera with a double female USB adaptor, but I'm not entirely sure that it will read this as an input. Also, I need that port available for when I calibrate the system on the computer. Does anywone know how I can modify the male USB connector of the camera so that I can plug it into one fo the NXT's input ports? Any help would be great. Thanks!

Question by pyrorower   |  last reply

Can I change the distance the axis move per motor turn on a homemade CNC machine? Answered

Currently, I really want to make my own CNC plotter. I want to try a different approach so instead of using pulleys or threaded slider to move the axis, I'm planning to use 3D printed rack and pinion to move the platform. I will limit the movement by using drawer slides. However, the thing that bothers me the most is that can I calibrate the movement of the stepper motor to move exactly a distance I want? I mean if the gear's perimeter is 2cm, then 1 turn on the motor will make the axis move 2cm, definitely different than using pulleys. Also, can I convert PCB prints from eagle to Gcode to control the plotter? (my goal is to make a plotter that can make PCB) I'm sorry for the lack of picture. I want to make sure that my project is possible before I start doing it. P.S.: Is this a good idea? Or is it much better to mod my 3D printer into a plotter? I'm planning to buy a Monoprice mini printer fyi. 

Question by Shizen   |  last reply

Modifications to LED Bar Graph Volt Meter for 12volt batteries(and Battery banks) Answered

Hi I found this LED bar graph voltmeter at want to understand how to build this voltmeter.But please read the solorb website page before posting, for more info.1. What is an offset resistor???2. What is a 'span'(see pic notes)2. For 12v operation,short J2 and J5,but what to do to all the other unconnectd 'J 'wires, just join the wires or what?3.To use without the Blue LEDs, just remove the two LEDs or any other connection/shorting is required????4.What is switch S1 used for ???, I do NOT want to manually push switches while the meter is in operation.5.How to stop the blink-LED mode, I want the constant display mode always.6.There is also two arrows shorting two pins on the IC with words 'Adjust for 12v'?????????7.How to calibrate the circuit accurately???PS:- If you want to know more about a larger part of this project,visit

Question by mhkabir   |  last reply

Wiring 2 pots together?

Ok, so I am in the hobby of hobby grade rc. I am currently working on modding a ps2 racing wheel and foot pedals to work with a spare 2.4ghz remote I have for my cars. I got the steering wired up fine and it works good. Now for the somewhat tricky part. The foot pedals each have a potentiometer in them. They share ground and power, and have separate signal outputs. I have the right one wired in for the throttle just fine. On my micro car it was easy enough, just switch the throttle reverse switch and push the pedal and it goes in reverse. But most escs wont calibrate to that. How would I go about wiring them together? essentially I want to turn 2 pots into one big pot. So when I push the right one down it sends the signal for forward. When I take off the right one and push the left one down, it signals reverse. I could bring my micro controller into the mix, but I really dont want to for something that seems so simple. Plus it is on a serb right now. Any help?  Thanks

Question by TOCO   |  last reply

Creating a more inexpensive sous vide controller ($27)

While i was at home depot the other day, i noticed that a thermostat from an electronic water heater could possibly used for (almost precise) sous vide. Temperature regulation (it goes from 120 F to 150 F). The question is, i need your minds to help me in collaborating on a circuit setup which makes this possible. Thermostat: Costs: $14 Plug to plug your slow cooker in: $3 Pump to circulate water: $10 Total Cost: (without cooker): $27 *Future Instructable Contents* -As the thermostat works through surface contact, Place the Thermostat  near the top of the metal vessel. -In order to better stabilize temperatures, make sure the heater is near   the bottom of the vessel. (we'll just use a heat plate or something like that) -Use a pump to stabilize the temperature better. -The knob just really requires better calibration. Hystersis: 18 Degrees. The million dollar question Just say i set it at 150 and the hystersis is 18 degrees, that means it will turn back on at 132. Especially with sous vide, Is all that matters is that the food stay at the top temperature, (say 150) and it can go to 132 as long as the solution as a  whole never goes above 150? In theory, this setup will just require more time to to heat evenly and correctly. Sources question:

Topic by compatta   |  last reply