Tachometer (RPM Meter) || DIY or Buy || How a 3€ sensor outdoes a 29€ product!

48 Comments

1. 

   Is the speed dropping in the tachometer since an external torque has to be applied to rotate the tachometer?

2. 

   Homemade products are the best, greetings from Mexico

3. 

   Just got mine to work : = )) Had to change the resistance pot some to get to start reading.

4. 

   I hate watching yr video. ? i realized how stupid i am. Thats nice. I can apply to count the rpm for my electric outboard motor
   Thank u so much

5. 

   I'm so going watch all your videos today.

   Forget about Marvel or Disney….thanks for great entertainment.

6. 

   ❓❔??❓❔Would this work on a push mower ??? I need an tachometer just never wanted to waste money ? ? on something I can use my ear to adjust it but should get one for my peace of mind ☮️☪️??✨?????

7. 

   The ATMega328 has an internal comparator that could be used instead of the other circuit board.

8. 

   What music do you use as a benchmark for your audio projects I couldn't find them on Shazam

9. 

   Great Scott, I am big fan of you and you never make mistakes but I am afraid this time you did using the tachometer attachment incorrectly to measure the RPM.
   The way you used the attachment measures the linear travelling not the RPM. To measure the RPM tachometer attachment must be coupled with the motor shaft, face to face, not the side by side.
   In your case change in shaft diameter would change the reading.

10. 

    Great video !! in the schematic of IR distance measuring sensor there is hystersis resistor connected between the output and the non inverting input are you sure this is not there or did you miss it ? Those square are just too perfect lol may be C1 is acting like a damping cap but still never seen such a beautiful square wave on any comparator without a hystersis or at least it is a good practice.
    Secondly at the beginning of the video would be nice if you mention the applied voltage to the motor and the current consumed by it at no-load so optically measuring the speed and current consumed when you probed it with the rotating shaft of the tachometer it is just for my interest thank you for your videos…

11. 

    Eminently useful video series – Thank You.

12. 

    $20. wow its cost too much. i thought it around $10

13. 

    Pls can u explain why u multiply by 120 not by 60 sec in the code?

14. 

    где скетч?

15. 

    Excelent! Could you make an RPM meter in a non invasive way to measure an combustion engine? Something like measuring the spark plug cable triggering in an inductive way… that would be great!

16. 

    Can anybody answer me if i can use Hall effect sensor to detect signal outside of spark plug wire in vehicle in order to count RPM. And if the LM2917N ic is required or not?

17. 

    Can I just replace the sensor with a 3144 hall effect sensor module?

18. 

    bei mir kommt es leider nicht mit hohen geschwindigkeiten klar 🙁
    400 gehen noch aber mein akkuschrauber mit 1400 geht leider nicht

19. 

    ☆Awesome☆ You are a real pro!

20. 

    Can l use pulsein() function?

21. 

    what about using motorcycle tachometer

22. 

    hi bro tks for sharing.
    i have a similar project , but a have problem for noise for interrupts 0 even when i don't impact to interrupts 0 it also happended interrupts , it causes signal disturbance that causes error calculation. have you encountered a similar situation. can u help me reduce noise interrupts?

23. 

    Most Arduino guys are hobbyists or students and not experienced enough to code using the register. It would be nice to see a sketch using the Arduino normal IDE commands that they typical Arduino guy can understand.

24. 

    Need more speed, how about 10K RPM?

25. 

    Thanks for reverse engineering the circuit of the module! I used your schematics to figure out how to add hysteresis (Schmitt trigger) to the circuit: You can easily add positive feedback to the comparator by adding a resistor between the output and the non-inverting input.
    I just soldered a 20k resistor between the OUT terminal and the anode of the Photodiode on the backside of the PCB.
    I did this because I had problems with false interrupt triggering on an ESP32 using this module. Apparently the ESP32 external interrupts need a quite fast rise time to trigger reliably. It would have been interesting to see how noisy the rising and falling edges of the signal in your setup are by zooming in on the DSO.
    The 20k might not work for all sensitivity settings of the trimmer pot. To change the hysteresis it might be a good idea to replace the resistor with another trimmer pot.

26. 

    Hello. Thank you for the great video. Just made a tach based on your hardware and code. Everything works excellent. EXCEPT my readings are doubled than they are in fact. Any suggestions? Thanks

27. 

    Yeah, watched the timing video, and still hard to follow. Can someone recommend any good source: video, reading or such, that goes a bit more slowly through the explanation?

28. 

    Hey Scott! Thanks for this great video. I'm also trying to build the same circuit with a few differences. But the problem is i'm using Pro mini 5v 16mhz. I think timers are messing up at this clock. I'm pretty new to these. What should i change in order to make this work with 16mhz pro min? Keep up the good work, thanks for the educative videos!

29. 

    3:12 Du soll test das Messteil nicht seitlich dranhalten, sondern direkt oben drauf, desswegen hat es eine Vertiefung an der Oberseite.??

30. 

    Really you did hard work, worthy to watch complete video . Excellent ?

31. 

    my arduino ide freezes wihle uploading your code unfortunalty i cant find the fehler

32. 

    It works as expected. Except it can not measure under some 150 RPM. Any idea how to make it do measurements of some 30 RPM?

33. 

    i suggest that you STICK with projects that do Not involve mechanical physics. googletranslate

34. 

    did one of those adapters have a rubber, CONCAVE end. if So, THAT should have been pressed against the END of the motor shaft.!!!!!!

35. 

    at :59, you are, clearly, short-on mechanical physics knowledge. this interaction of two Different RADII, results in a rpm CHANGE !!! eg., step-DOWN ! googletranslate

36. 

    since your testing methods were FLAWED, so too is your opinion of this tach.

37. 

    at 4:06, same On the motor SHAFT issue.

38. 

    at 3:38, this a GEARMOTOR, not a slow motor.

39. 

    at 3:00, just how unimaginative are you. PUT A ROUND something on the Shaft, so that the tach can more-readily detect individual return signals. googletranslate

40. 

    ummm. 'white tape' ???? REFLECTIVE tape !!!!

41. 

    Urmom

42. 

    Buy

43. 

    scott: SPONSORS JLCPCB BUT doesn't use their pcb but you can send the scematic as a gerber and order a pcb

44. 

    I think your video is great! I can tinker with Arduino. I draw with the elek. CAD and then I can order JLCPCB. Perfect! ???

45. 

    Can I suggest a CFM mod/attachment? Spin a fan of known diameter, use the tach on that? Then press a button to switch to that calculation?

46. 

    Why not take advantage of your full OLED screen? By offering a cool display? Three ideas come to mind:
    – a tachometer display (with a needle)
    – a graph (with values logged in the last 60 seconds)
    – a frequency display

47. 

    If you had bothered to read the instruction you would see that you need to use reflective tape for the rpm. meter to work proberly.

48. 

    2^16 = 65536