can relate lol

Hello You can reply me

I have need it's

It seems a simple software calculation in the program can mulitiply a predetermined volume per revolution × revolutions per minute or per second.

I don't know why this guy using float to count revolutions which is in integers, and using volatile is better practice to avoid errors in shared variable due to asynchronous read writes to it between interrupt routine and normal code. I am not an expert but you can get accurate result by calculating exact time between 2 pulses using micros() function inside interrupt routine to get exact time when interrupt occurred.

@@balkrushnakadam7082 something to look into so far the best one I've seen is this one kzfaq.info/get/bejne/q5ilfbB7vNnKo5s.html but I don't have that display and for me the code is difficult to follow, it's a over my skill level

@@patrickmclaughlin6013 maybe I can help you with that if you want I have written simple code to measure rpm accurately upto 60000 rpm you can try this by yourself. volatile unsigned long pulseTime1=0,pulseTime2=0; volatile boolean flag1=false, flag2=false; unsigned int rpm=0; int pulsesPerRev=1; //you can change if you have more pulses per revolution void isr() { if(flag1 && !flag2) { pulseTime2=millis(); flag2=true; } if(!flag1) { pulseTime1=millis(); flag1=true; } } void setup() { Serial.begin(9600); while(!Serial) { } attachInterrupt(0,isr,RISING); } void loop() { if(flag2) { noInterrupts(); rpm=((double)60000/pulsesPerRev)/(pulseTime2-pulseTime1); flag1=flag2=false; interrupts(); Serial.print("RPM :"); Serial.println(rpm); } } For more stable results just take multiple samples of rpm values each iteration and try to find median. If you have way more pulses per revolution then results would be less accurate at higher speed if time between 2 pulses gets below 1 ms, to correct it you have to use micros() function instead of millis() inside isr() and use this formula instead of above one rpm=((double)60000*1000/pulsesPerRev)/(pulseTime2-pulseTime1);

@@balkrushnakadam7082 Thank You for the example code. I'll have to put it up on a sketch and give it a try.

Lank Asif use 555 based circuit and its app to calculate Frequency

stroboscopes have limited applications and require known strobe pulse rate, which defeats the purpose in the example shown. Strobes can be programmed at the emitting pulse width, so why would you need to analyze it? Strobes were often used to detect a stationary point of a rotating object and that's about it. That's easy to do and hackster.io has several examples. There's even an app for android for a strobe app - play.google.com/store/apps/details?id=com.ape.apps.strobe&hl=en

X-TREME Diy Thank you but I am looking for a reliable stroboscope setup that can be used to drive a large LED array (for an exhibit of sorts). I am not attempting to determine a rate at which an object is rotating or oscolating, I was requesting help in the form of an example of how to build a stroboscope in a way similar to how you demonstrated how to build this tachometer. I live in a third world country so finding a stroboscope is difficult and expensive. Thank you again for taking the time to respond to my message.

Doug Hanchard X-TREME Diy Thank you but I am looking for a reliable stroboscope setup that can be used to drive a large LED array (for an exhibit of sorts). I have been warned that a 555 timer build is not reliably accurate when dealing with rates as fast as 50 or 60 Hz. I am not attempting to determine a rate at which an object is rotating or oscolating, I was requesting help in the form of an example of how to build a stroboscope in a way similar to how you demonstrated how to build this tachometer. I live in a third world country so finding a stroboscope is difficult and expensive. Thank you again for taking the time to respond to my message.

Circuit diagram totally out of wack with the board layout and values vary too!

It will not drop voltage , it just sense the voltage. Its better to call it IR sensor not a normal Led.

@@SAYANDALAL Look at ATmega168/328 datasheet, Input HIGH is 0.6Vcc and if Vcc is 3.3V then the minimum input voltage is 1.98V It may work of course, but working on the edge is not recommended and also can trigger false results. Why not simply connect the signal from op amp trough pull-up resistor to arduino digital pin with no LEDs inculuded ? That way you asure the input level voltage.

@@mindaugask6160 i make that same tachometer in simple way. Using ir sensor. You can see in my channel. 20 types of dc motor rpm shows there. Its working really fine.

@@mindaugask6160 I'd skip the comparator. And instead use the analog inputs directly, and compare the two inputs in software. I'd also get rid of the display diode and use the display screen. The potentiometer is helpful for dialing in the right reference voltage to compare against various light sensing diodes. But maybe you make a point on color. Maybe blue LED sensor might have trouble sensing infrared light.

Md. Abdur Rahman Wahid Go to the links provided.

First led transmit ir then that is reflected by white surface than received by ir photo sensor , so when it rotate in case if paper are not present their then singnel will be low otherwise when present sing will be High so this high low signals act as variable revolution or as Frequency that is measured by naino , you can also try for this by Stroblight Method instead this , it's non - programmable and easy as well as cheap :)

White color reflects ir light so basicially an ir switch

Solar cells and rectifying diodes and Light editing diodes use an NP junction. All NP junctions either emit light at a certain freqency when you pass a current through it, or absorb light at certain freqency and elevates electrons to a higher energy state pushing them through a circuit. The comparator compares the photo diode output against a reference voltage dialed in by the potentiometer, and digitizes the comparator's output to on or off.

With in a week

So yeah, I'm like why don't you use the analog inputs and do a software comparison. And get rid of the LM and display diode and use the screen for a display.

After adjusting the potentiometer for a given setup, i'd trust it over short distance like this. One might shade the disk from external light sources to add assurance other light sourced don't interfere with measurements.

www.mediafire.com/file/n6xwp1oc6wl4oys/game_grbl.rar

Thank you for the prompt response but I think you sent a game layout and not the Tacho layout.

extremely sorry www.mediafire.com/file/dai45xoabmt60a0/tachometer.rar

Thanks, I have ordered the boards successfully.

This small motor has that much rpm. And it can be more than 10000 Rpm for many motors of 3 or 6 volt even 12 volt. YOU can check 20 different types of dc motor rpm in my channel.

8000 rpm is very reasonable on small motors. For one, they don't have a large diameter and high forces to condend with. It's only 133.3 revolutions per second. That is just slightly faster than twice the speed of much larger synchronous AC motors in the US that spin at 60 revolutions a second.

NAMBI RAJAN I’ve test this RPM meter and in my case it works only with 1 type of IR sensor! See vid. : kzfaq.info/get/bejne/kLyibLqmpqmviWg.html

Print it in the setup function and a few seconds delay after

@@3dmixer552 i tried but it show my name for 1 second as i set it to 1000 ms but it is continiosly doing it

@@a.manan.s846 clear the screen after the delay. lcd.clear();

@@3dmixer552 ohh thanks

@@a.manan.s846 No problem

It is what the software does. It can keep a count, or it can ceep a count over a period of time and convert that to rpm. Or it could do both if you wanted to program that in.