Arduino tachometer using interrupt. 16: 34285: May 6, 2021 Help with IR-based tachometer.

Arduino tachometer using interrupt The angle between 0 and 5000RPM is 265 degree. Output is to a LCD screen in RPM. The problem is that my displayed rpm is very erratic and not accurate at all. e when I calculate the RPM Manually using a stop watch- for lower speeds). So I get a bit stuck on how to fix this. The example shown here is just about the most basic case for using an interrupt - you can use them for reading an I2C device, sending or receiving wireless data, or even starting The PWM control part works fine, but the RPM readout is a bit erratic. I graduated more than 30 years back and have a background in Electronics Engg, so I know the basic concepts (V= IxR, etc. With the conclusion I mentioned earlier, we can easily read the signal with an Arduino. I am using pwm to do that using a circuit with a TIP120. Counting the RPM. I know the idle of my lawn mower is 1600 rpm but my tachometer displays between 800 and 2000 Hey, I'm trying to use the following code to measure the RPM using a KY-024 sensor on my Arduino UNO. Here's what The only difference is that instead of using 3. The motor takes a 20-100Hz PWM input and has a tachometer output. As always you can go through the external link for more details https://www. The components are the following: IR phototransistor: 3mm,SFH 309 FA-3/4 with 10k ohm resistor IR Hi all, I'm new here and am gradually getting my head around programming the Arduino. Instead of a slotted sensor , it has a reflection based sensor. I've set up several different versions based on projects found on the web, each with a caveat or two, so I'm seeking some input from anyone who has experience. My LCD monitor works great i guess. She is a Chemistry major and I want her to have multidimensional skills as she prepares to go out into the big bad world. The signal is a 12v squarewave signal, I need to convert this to a 5v squarewave signal, but im not sure on how to do this, I tryed using a Hi, I am still relatively new, and I still do not fully understand capacitors, but I'm thinking that is what I need in this circuit. The way my program works. By interfacing an IR sensor module with Arduino and using a 16*2 LCD display, we can monitor and display RPM with precision. I've a hall effect sensor stationed on the side of the machine and a magnet on the fly wheel for counting rpm's. h> #include <LCD. They appear to work well in some of the videos Hello, I work on a tachometer to a Fuelcontrol system for cars. How much would this ruin your lecture? Not very much. But, when the loop starts doing anything else, it misses the start of the incoming IR data, therefore reporting an unknown IR code. However, there must be some hidden problem in my sketch and I'm not able to find it. I'm looking at it as if the RPM's are 200+ Hi! I'm working with a laser tachometer using an Arduino Uno. Although you can use any Arduino board you want, but we are using Arduino Nano in this article. My thought is this: I have an old Smiths Tacho that is certified dead, but very tidy looking and I have a friend with a Mini we converted to Megaljolt ignition. This circuit is for a project in my car and I have seen this behavior there, but the easiest way to reproduce it is by touching the circuit with my finger. For example, in between 2 pulses of a signal say Z, The Arduino will be counting number of pulses from another signal "X". Arduino Hall Effect Sensor With Interrupts: Hi Everyone, Today I’ll show you how you can connect a hall effect sensor to an Arduino and use it with an interrupt. I try to count the number of interrupts (revolutions) in a 1000ms delay and calculate the RPM. This is my first time programming an Arduino so sorry if I am not able to explain further. h> #include <LiquidCrystal_I2C. I wanted to use a Magnet and a Reed Switch to meassure the RPM, for that i needed to debouce the Signal from the Reed Switch, since i couldn't find Hi everyone, I'm trying to get a RPM reading from a Hall effect sensor triggering an arduino input. This sensor uses an infrared LED on one side, and there is a Thankfully, using the “PinChange Interrupt” library, we can configure any pin on Arduino an interrupt pin. We started by understanding the basics of Hall Effect sensors and then introduced the A3144 Hall Effect sensor, which is Easy peasy reliable tachometer, that you can use to measure the rpm of tools, bicycle wheels, and robots using inexpensive parts. h> void setup() { Serial. When I logged the output from the serial bus, I find that when it jumps, Counter is nothing but a device or setup that can count any certain regular occurring event like passing of a dot in disc while in rotation. com/make-any-arduino This is a simple yet effective RPM tachometer using Arduino UNO and an IR sensor. I'd like to also know their RPM. Below is my code which I have edited and compiled from different sources. Our Fluorescent lights read 7200rpm on an optical tach. The whole program is Tachometer, interrupt and square wave Using Arduino. It seems that the progamme doesn't Newbie here so please correct me if I'm wrong, be it wrong post category or any other methodology/code errors described below. begin(115200); attachInterrupt(0, tachPulse, RISING); time = I kind of like using, for this kind of thing a user interrupt pin to detect the raising edge of the signal and in the interrupt ISR use either millis() or micros() to 'timestamp' the signal and set a flag with each new update, then in the main loop calculate the time between the newest reading 'timestamp' and the prior and calculate then Hello! This is my first project with an Arduino. I'm using a IR sensor and a IR emiter (I can use a LED for that purpose). Hi everybody! So recently i was working on a Project where i wanted to meassure the RPM of one of the Wheels on my Car, and from that calculate the Speed, keep track of the Driven distance etc. 19: 1808: May 5, 2021 Inaccurate Tachometer readings. A little project I've been working on is a RPM display for my drill press using a A3144 hall effect sensor, an arduino uno and a 16x2 lcd display, I'm having some trouble Hi there, I am trying to make a project using arduino UNO and some slot cars. Project Guidance. Use a Hello, I'm working on optical tachometer that measures a delay between two pulses and calculates rpm. A tachometer is a device that is used to measure the speed of rotation of any device. Sensors. The cable that leads to the hall effect sensor is Can I use different types of interrupts (RISING, FALLING etc) for two different functions of code to run different scenarios on a single interrupt pin. Now I've stripped some code to get to the core but still can't figure out what's going on. Hi guys, I'm new to Arduino programming and am having a "make" using a Nano I've had for a while - I'm bored with just dimming an LED now. Putting a 50ms delay allows only one pass of LOW though at least every 50 ms. Arduino Uno, which uses a less precise oscillator, would drift a lot more. This page is also (photo-interrupter) trying to catch a coin drop. I've hooked it up to my lcd to view the RPM and the RPM difference. But the problem is the monitor always shows 0 rpm. Arduino 2009, with using a crystal for 16 MHz, has a drift of many seconds at day. The chipper gets jammed up when too much scrap wood tries to go all at once. It has a downward sloped ramp that goes into the chipper that vibrates the scrap wood into the chipper (called the shaker). Here's what I've tried and learned: I tried every capacitor I have and they all had no Arduino tachometer used to calculate the rotational motion of a part. So I tried to control some PWM fans using Arduino. The issue I am having with my code is that I cannot get an accurate RPM value. rpm keeps fluctuating between cca 2000 to several Hey all i am trying to make a tach that i can read the cars RPM's. I am looking at making a tachometer that uses the Switec X25 motor and a squarewave input which is 66Hz at 100RPM with a max RPM of 5000RPM. Oh, I also changed to Arduino power to a 5 volt cell phone charger and added a ground wire to the mains wiring ground. Materials : arduino mega2560 ,IR sensor TCRT5000 Infrared Sensor Module - Line Track, LCD screen 16x2 , SD module MicroSD Module with SPI interface (for Arduino) and a couple of buttons. I need the system active when "speedPin" reads over 433counts/hz? and the system deactivated when "speedPin" reads less than 433. Using interrupts is very appropriate in this application. I had to use the prescaler on TCCR2 to get to the lower Hi there! Completely new to Arduino. I am trying to make a tachometer to constantly monitor the RPMs of the propellor shaft in a friend's 80 year old boat. IR transmits IR rays which reflect back to the IR receiver and then IR Module generates an output or pulse which is detected by the Arduino controller when we press the start button. I need some help. 1. In all of these situations, using an interrupt can free the microcontroller to get some other work done while not missing the input. In this project, we will show you how to create a device that measures the RPM (revolutions per minute) of rotating objects like motors or fans. How can I improve this for more accuracy at lower RPM? Thanks // IR Hi, I was trying to sample a tachometer using interrupts but got strange results. 16: 34285: May 6, 2021 Help with IR-based tachometer. Maybe an orange thrown in there 😃 The "redline" will only be 4500-5000 RPM. I checked the actual PRMs with a tachometer and it is about 20 to 30 rpm from the readings given by Arduino Forum Controlling 12V PWM fan & reading speed (tach readout issues) Must be an interrupt capable pin (2 or 3 on Arduino Uno) #define DEBOUNCE 0 //0 is fine for Building a tachometer using Arduino is a rewarding project that allows you to delve into the world of electronics, programming, and sensor technology. 15: Hello all, I am attempting to write code to program an Arduino to calculate the RPM of a rotating disk. Are you looking for a way to measure the speed of a rotating object using your Arduino? Building a tachometer with an Arduino is a fun and rewarding project. The speed of the motor can be also controlled using the same circuit. The easiest way to build a tachometer is using a transmitter and receiver. Initially the counters were built using the mechanical arrangement and linkages like gears, ratchets, springs etc. Simple design : 40 LEDs for RPM indication and a 16x2 LCD display for useful info. I've calculated the time it takes my other functions This article is about a contactless digital tachometer using arduino. My car (from the 1960's) does not have a tachometer (REV counter). If you were going to determine rpm by counting the time between falling edges of the spark pulse you should be using interrupts. Here, in this column, we’ll describe the making of a digital tachometer and let me tell you that it works on 2. I use the most common strategy for this, using interrupt to count revolutions over time. ben999 September 14, 2014, 8:12pm 1. This is my plan's vague outline so far: Use a transformer from a wall adapter to step down the generator's output voltage. Unfortunately, you were not Hi, i want to make a speed tachometer for my bike with a hall effect sensor For testing im using a arduino uno and a 16x2 lcd with i2c. Tachometer is usually used to measure the rpm of Basically, I am finding the rpm and speed outputs (interrupt timing pulse widths) to jump from time to time. As a result the This is a basic Tachometer, it uses a Hall effect sensor to detect a magnet on the shaft of the device you are measuring the speed of. Maker Updates. Still errors. RISING, FALLING, and CHANGE events aren't registered when the Arduino is asleep, which is the only situation where use of LOW makes sense. And I have problem with the stability on the tachometer. When the link between them is broken, you know that something is spinning and can execute some code that calculates the current RPM of whatever is spinning to break the The circuit diagram of the digital tachometer using Arduino is shown below. This interrupt is timing the interval between two pulses On D3 I have a wire connected to D9 that generates Here we are going to design an Arduino-based digital tachometer using an IR sensor module to detect objects for count rotation of any rotating body. I'm using an ISR to read the PWM tachometer signal on D2 and Timer/Counter2 to output a ~30Hz on D9 (OC2A). And a bunch of LEDs for indications such as neutral, low fuel and I need help with programming an ISR with the one and only external interrupt on the ATtiny85. So far, I have completed the TPS section where the Arduino reads i have a shaft that is turning at a constant rpm connected to the shaft are 4 magnets, the magnets tigger a square wave signal to the arduino using a active sensor the rpm transmitted is quite unstable - it jumps about quite a bit code here volatile int tachCount = 0; long time; long rpm = 0; void setup() { Serial. brainy-bits. begin(9600); attachInterrupt(0,timestamp, FALLING); } void loop() { } void timestamp() { Serial. Consider the code below const byte PIN_TACH = 2; // Tachometer pin const unsigned long T_SAMPLE = 200; // Sample period volatile byte counter = 0; // Counter to be increased in interrupt void setup() { Interrupts have a "natural call priority" in that lower numbered pending interrupts will be called in preference to higher numbered ones, however that doesn't mean that they can interrupt each other. When it's the only thing in the main loop, it works fine. Further voltage-divide the transformer output for use as a tachometer input to the Arduino's comparator. Using interrupts not "interruptions" is essential to the voltage its less than a volt. Interfacing. I have tried MANY things and nothing works. However, this RPM doesn't match with my manual calculation (i. ) To test the code I use an PWM pin (uptime Hello I have a routine that detects incoming IR (IRremote library). I followed all the process that who made before. This produces a clean square wave as can be seen on the oscilloscope (see photo or Hi, I'm trying to use Arduino in order to calculate RPM. Before we start, we should understand how this sensor works. Now I am attempting to add a "anti-stall" function. I am only looking for the chip to see what the RPM's are and not display it out to the user. TACH with in 4 rpm at 1025 rpm ! , I had some work to do but thats fine I am learning A-LOT from you Dog ! In fact Its called Cattledog Tach in my file names LOL . Someone can give me a little bit of light about it? #include <avr/interrupt. The idea is to keep the engine of a generator at 3600 RPM regardless of load. I configured the input signal to count on both fronts, and added a I'm trying to use an Arduino Nano to control a micropump motor. I have been working on an automatic magnetic coil pickup winding machine the last while. On D2 I have a pin connected to an IR obstacle avoidance sensor to measure the RPM of a wheel. I expect their frequencies to stay in a range from Usually, calculating RPM via program involves using timers, counters and interrupts. I'll show the code what I used. It counts the revolutions of a rotating object using interrupts and displays the RPM on an OLED screen. h library and that one I cant use with an ESP32. So one of my latest projects is to make a digital tachometer. I am using the code given below inorder to caluculate the RPM of the DC motor. I needed to build a I plan to use the code below to make a tachometer (24 led, each led is 250RPM) The idea is that a square wave triggers an interrupt, the time between two of these is logged and subtracted to get the time between pulses to determine the RPM. The start time and the last interrupt time is recorded in micros(). This program basically monitors the IR sensor's value The Arduino programming language Reference, organized into Functions, Variable and Constant, and Structure keywords. My objetive is make a simple tachometer with arduino, but I don't be able to to entry in the interrupt. It counts Hello All, I'm trying to measure the time between two pulses with a ESP32 Wroom with interrupts. You need to check if the elapsed time is negative I added a low pass filter to the input and still got the bad interrupt count on occasion. The interrupt mode, which determines what pin action triggers an interrupt. Read about the latest maker projects, skills, tool reviews and more. 3. Menu; Greenwaykitchen. This adaptable tool is useful for controlling and Emitter of the photo transistor is connected to the Interrupt 0 (digital pin 2) of the Arduino. I changed the interrupt from falling to rising. The only thing it gives me is how to set up the registers, which I have done below. Using Arduino. Now, let’s see how to use Interrupts in Arduino, which functions are associated with interrupts in Arduino, IRQ pins, trigger modes, and much more. This Instructable will show you how to make a Portable Digital Optical Tachometer using an Arduino Uno. If the interrupt is triggered in the mean time, that can cause the lsB to roll over possibly corrupting the total value. I'd like to gut the Tacho and use a RC servo to swing the Im trying to make my arduino read engine speed. I have been trying to test some code using a nano but the first problem I have found is that if I apply the 12V from my old instrument to the VIN on the nano Hi, i am new programming Arduino and I'm trying to make a meter taco using an infrared receiver and an infrared LED, the code I found on a page and upload it to the Arduino, and connect all the cables and had to change the location of some wire because they were wrong in the diagram, but when the arduino is connected rpm begins to show on the LCD when I want to build a simple LED bar graph tachometer. The Hi everyone, merry xmas and happy new year. I tested it up to 30,000 rpm ! I get good loads and temps at that speed , I still need to check the SD card Arduino Tachometer - Using a Hall Effect Sensor (A3144) to Measure Rotations from a Fan. I am building an optical tachometer using an IR sensor. Using the analog voltage reading property of an arduino, this can be easily implemented using the appropriate parts. The chinese digital tachometers don't really fit the analog gauges in the dashboard, and are hard to read when the sun is shining on them. Arduino doesn't calculate rpm correctly. I am making an automotive project and would like to combine several items to produce a display on a 5 inch screen or possibly multiple smaller screens to show my cars AFR, RPM, TPS and MAP sensor inputs. I have at my disposal an IR phototransistor and IR LEDs. 3v I'm using 5V so I can use the same power source (a usb-powerbank for now) for the display, the arduino and the optocoupler. Wiring A very simple way to make a tachometer where the result is displayed on an OLED display in the form of an RPM number and a progress bar Arduino Tachometer (RPM meter) with IR sensor module Apr 22, 2023 Hello Everyone, I have read multiple posts dealing with using interrupts for the determination of RPM of a motor or propeller, with or without a Hall Sensor, IR sensor, etc. I have read through the ATtiny85 datasheet about 700 times. If your sensor give a signal like 0 V to 1 V, well get a comparator ( LM339 ) Vcc of 5 V for the comparator, use / set a voltage divider of one of the op-amp input, and place the signal at the other op-amp input. I'm wondering if it would be better to reattach If you are getting a clean digital output from your breadboard to the interrupt pin, there is no need to change the sensor from reflected ir to Hall. I want to create a circuit so when the rpm's drop at a designated number, it will cut off the shaker. I get a reading on my serial Monitor. I've got an AC sewing machine motor with speed being controlled by a 5v servo whose shaft is mechanically coupled to a potentiometer on a variac. I am back into my project of building a dashboard for my racetrack motorbike. Last possible problem had to be the rotating sensor part. I want to get the signal from my exisiting tacho signal used to drive my tacho in the dash. It shows "TACHOMETER" , "0 RPM" as the codes mentioned. The code works "as is" without the interrupt function. Here is a hello, I am trying to count reluctor teeth with a hall effect sensor. Any help is appreciated. The first one worked fairly well using an IR transmitter/receiver through a Schmitt trigger to Uno's Welcome to our guide on building a Digital Tachometer using an IR Sensor with Arduino. ). Hi all. Learn. It is the voltage signal from your sensors ? No good for a digital pin. Get hands-on with kits, books, and more from the Maker Shed The easiest way to build a tachometer is using a transmitter and receiver . We will try to read every time the signal from the sensor is falling or changing from HIGH to LOW. The tacho works on an Arduino R3 board but I would like to use a pro-micro clone instead, the version I have is 5V 16MHz: I'm using the Arduino IDE with the arduino-pico core and I'm trying to get pin interrupts working for a rotary encoder application. I have used one hardware counter and two interrupts in this project. I am Hi, I have been trying to create a system that will count the number of pulses read on a pin in between pulses of another signal using interrupts. I will describe my program the problem. However, when the interrupt is called, the 'delay(1000)' step (in the loop section!) seems to be skipped and I get erratic results. h> #define Hi all, I am new to interrupts and struggling with the interrupts. Although writing Arduino program for calculating RPM is not hard and though sketches for Tachometers can be found readily on the Internet, still comparatively it is bit faster and saver to use the Simulink Tachometer sensor block(it uses interrupt service I'm just wondering why with this simple code without using interrupt method, I have clear values on the serial monitor, without these kind of noises? Pulse reading circuit (tachometer) for arduino. Programming Questions. I've been tinkering with practice code making led's blink and stay lit plus some sequencing so the hardware side won't be much At a sawmill we have a chipper which runs off of a ac motor. The circuit diagram of the digital tachometer using arduino is shown below. Like this: #include <Time. Books & Kits. Search for use a high-resolution rotary encoder, calibrate the tachometer carefully, and consider using a timer interrupt to measure the time between pulses more Hi: I'm using this to read RPM from electric motors. I found the sensor works properly with light blinked when I did some movements in front of the sensor. I am using a tachometer to change the motor speed of the cars. Based on Noctua, Sanyo Denki, and Nidec (sorry the Nidec link being NOT sourced from Nidec but rather some third-party vendors), I believe that I am using a quadrature encoder (ppr=400) and Arduino Uno for this purpose. I have seen some examples but all use the TomerOne. with an Arduino. ( as every interrupt count is rougly 15 steps ) even with steady input frequency. Ive written the code using interrupts, only problem is the hardware side. The interrupt occurs with a frequency from 1 Hz up to 130Hz Here is my code. Perhaps 1000rpm= 2 lit, 2000rpm= 3 lit, 2500rpm= 4 lit, etc. I've taken a Arduino beginners course a while ago and have made some useful (and some not so useful) projects since I've finished the course. Write some simple test Hello Forumees, I've read through the forums a lot regarding a Tachometer plan WITHOUT using an interrupt function, but I couldn't find one. Previously I did the same with a MEGA with some help here on the forum but with the MEGA I used a pin read to see which pin had Hi, I am a student during my Internship and I am trying to create a tachometer using an IR sensor. Of the Hi, This is my first post here. Tachometers read out revolutions per minute (RPM), which tells the user how often a rotating part completes one full rotation. I can't find any tutorials on how to do this except for a couple people have done a Hi all, I've been working with the idea of building a tachometer to be fitted on my older Kubota tractor. 60Hz AC from the wall (120 half cycles 60 going above the zero volt line on the scope and 60 going below the zero volt line) so 120pps times Topics such as microcontrollers including Arduino and Raspberry Pi, Drones and 3D Printing, and more. Hello everyone, I recently started programming with Arduino and and currently I'm making a project to read RPM and Speed of my car using Arduino Uno. println(millis()); } The serial port is monitored by a Matlab script which Hello all from a mechanical guy who knows just enough about Arduino to adjust others code to my needs. RPM readings are used in the Article is about RPM Tachometer with Arduino, After reading article you will able to check speed of dc motor or any kind of rotational device. Then But, with the up-gradation of technology, now, the tachometer can be made digital and contactless by using Arduino. There is no such restriction on most common types of Arduino because interrupt circuits and timer circuits are independent parts of the MCU chip. I am pretty sure it works accurately, but my question is to what rpm (or interupt per second) I can expect reliable readings? This is my code: #include <Wire. Emitter of the photo transistor is connected to the Interrupt 0 (digital pin 2) of the Arduino. You can use your newly acquired skills to create custom speed-measuring devices for a wide range of applications, from automotive projects to industrial automation and beyond. Tachometers have a variety of applications, including measuring the speed of dc motors in order to ensure they are running according to specifications. I'd like to output a control signal while reading the RPM. The screen brightness can be adjusted with the potentiometer. I'm a complete noob so any assistance much Using Interrupts in Arduino. h> //Global constants const int pin_motor=2; //Pin interrupt 0 //Global Variables// I am looking at making a tachometer that uses the Switec X25 motor and a squarewave input which is 66Hz at 100RPM with a max RPM of 5000RPM. My project is a home made reliable tachometer that is easy to make. . So the sensor is interfaced correctly and I'm getting a reading (for example when I'm trying with the line put under Arduino Tachometer Code. Arduino is used for counting the RPM and displaying it on the LCD screen. As a result the will be an interrupt for every upward shoot in the In this tutorial, we have learned how to build a tachometer using a Hall Effect sensor and an Arduino. A tachometer is a useful tool for counting the RPM (rotations per minute) of a wheel or basically anything that spins. So far I got everything working but the speed value does not show properly. 12: 13222: May 5, 2021 Use arduino to measure and record engine RPM. My problem is that I have multiple codes in one Arduino, and using an Interrupt function to get the RPM every time a magnet passes by would greatly disrupt my other functions. Here are the squematics : I'm using external dc 12V . The idea is to use the signal from the negative side of the ignition Cattledog, Thank you for your help man! Turns out the tachometer acts very different on the engine vs a perfect Arduino spark emulator. (Same results as using the basic serial feedback. The RPM and all the other informations are displayed on a 16×2 LCD screen. The Arduino interrupt is configured to be rising edge triggered. Maybe 10-12 LED's, green, yellow and red. So, I need to add an interrupt to catch any incoming IR, but I just cannot get the code correct. It seems to work but the accuracy is +/-60 as I count pulses per second. I am pulling up input pin D2 and using a transistor to drain it to ground to trigger a falling interrupt Ok I got it working , so far so good ! I get RPM to the single digit ( not 60 ) and it matches my test/ref. I have read and viewed video's about this subject for days, but I have a hard time making it work. ApexM0Eng September 17, 2015, 10:05pm 21. There is no fixed value for the frequency of these signals. But now we are using counter having more sophisticated and highly We will learn how to use an optocoupler sensor module as an RPM counter or Tachometer. I tried reading every 100 millis but then when I multiply by 600 it gives even worse results. I added a reed switch that goes to digital pin2 and gnd. The function name of the interrupt service routine - this determines the code that gets run when the interrupt condition is met. The result gets scaled down to 250RPM increments and shifted out to 24 leds. Timer 1 on pin 5 - Count pulses from car's ECU to calculate speed. Speaking of the dedicated IRQ pins (external interrupt pins) in Arduino, they are different from one Arduino board to another. I've draw up how i think it should be hooked up but I'm still now 100% sure. RPM´s will be measured using interruptions, and the tachometer will be driven using the "tone" library, which is very easy to use. General Guidance. About Interrupt Service Hello. When i connect the hall effect sensors output to the arduino, the closer i get to the bike while its idling the more it "interferes" with it, (it reads 40kmh when the bike is standing still). Toggle navigation A not accurate approach is to use micros() instead of millis(). So I calculate rpm with the reed switch, and depending the Even tachometer() and the function that updates millis() are called from an interrupt, so even it would "break" your code. Circuit diagram. Or Hi! I have built a tachometer using an IR led and receiver. I am trying to do a project with my 22-year old daughter to get her interested in basic electronics and coding. The reflection of the LED on whatever is being measured triggers an interrupt via the IR receiver. Here is the code: #define ROTA 6 // GPIO6 rotary encoder A #define ROTB 7 // GPIO7 rotary encoder B // rotary encoder pin change interrupt handler void readEncoder() { encoder_state = (encoder_state << 4) | (digitalRead(ROTB) << Hi, I'm trying to create a tacho for my lathe spindle, I'm using the the design/code from linky The LCD will display text and if I amend the code to use the serial monitor on pin 2 I can see the IR logic changes state when something passes through the IR beam but the RPM on the LCD never displays anything other than 0. CrossRoads October 25, 2014, 4:16pm 10. When the laser is blocked, digital input 0 reads low, and an interrupt records the time. FYI I'm using an Atmega328 on a circuit board where pins 2 and 3(for ISR) are already in use. I built a tachometer for my riding lawn mower but it's not working correctly and I need some help. The more I research frequency counting/pulse counting, the farther I Arduino Tachometer Problem. 24: 25092: May 6, 2021 Home ; Categories ; Hi all. So the method is to disable interrupts, copy the 16-bit value into another one, reset the counter, and re-enable interrupts and Hello guys!! I am new with arduino. The problem here is that the servo library uses a timer (and its associated interrupt) to generate the waveform. It basically does but the delay doesn't correspond to the incoming signal. No Interrupt Tachometer. In this article we are explaining how to create a tachometer using Arduino. Arduino Interrupt Pins. I am using the LM2907 chip and tapping into the tach wire from the ECU of the car. Programming.