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

13. 09. 2020
227 679 zhlédnutí

$2 for 2Layer, 5pcs & $5 for 4Layer, 5pcs: jlcpcb.com
Previous video: csworld.info/mem/video/Y5imgoFk3I5ko5k.html
uC Timer video: csworld.info/mem/video/fMeBaJORrGuGZ6U.html
Facebook: facebook.com/greatscottlab
Twitter: twitter.com/GreatScottLab
Support me for more videos: www.patreon.com/GreatScott?ty=h
More project information (schematic, code,....) on Instructables: www.instructables.com/id/DIY-Tachometer-RPM-Meter/
Parts list (affiliate links):
1x Arduino Pro Mini: s.click.aliexpress.com/e/_dTWuuYz
1x IR Distance Sensor: s.click.aliexpress.com/e/_dXlui7F
1x 128x64 OLED: s.click.aliexpress.com/e/_dXOYM8H
1x TP4056 Charge Protect Board: s.click.aliexpress.com/e/_d697XPJ
1x LiPo Battery: s.click.aliexpress.com/e/_dUE2A0V
1x Toggle Switch: s.click.aliexpress.com/e/_dZ19w21
In this episode of DIY or Buy we will be having a closer look at a commercial tachometer (RPM Meter) and test it in order to find out that it is pretty much unusable. Afterwards I will show you how a 3€ IR distance sensor works and how we can use it to build a proper DIY tachometer that functions properly. Let's get started!
Thanks to JLCPCB for sponsoring this video
Visit jlcpcb.com to get professional PCBs for low prices.
2011 Lookalike by Bartlebeats
Killing Time, Kevin MacLeod

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

    chinh nguyenchinh nguyenPřed 19 hodinami
  • Pls can u explain why u multiply by 120 not by 60 sec in the code?

    Ahmed AlaaAhmed AlaaPřed 5 dny
  • где скетч?

    Валентин СелинВалентин СелинPřed 12 dny
  • 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!

    Daniel PontorieroDaniel PontorieroPřed 13 dny
  • 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?

    Дуриндер СингхДуриндер СингхPřed 17 dny
  • Can I just replace the sensor with a 3144 hall effect sensor module?

    Soroush HeidarySoroush HeidaryPřed měsícem
  • bei mir kommt es leider nicht mit hohen geschwindigkeiten klar :( 400 gehen noch aber mein akkuschrauber mit 1400 geht leider nicht

    MilanMilanPřed měsícem
  • ☆Awesome☆ You are a real pro!

    Trent JacksonTrent JacksonPřed měsícem
  • Can l use pulsein() function?

    Sefali BhakatSefali BhakatPřed 2 měsíci
  • what about using motorcycle tachometer

    john dale anthony gonzalesjohn dale anthony gonzalesPřed 2 měsíci
  • 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?

    Dinh Tan LoiDinh Tan LoiPřed 2 měsíci
  • 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.

    Eric The RedEric The RedPřed 2 měsíci
  • Need more speed, how about 10K RPM?

    S ToS ToPřed 3 měsíci
  • 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.

    Lenni ZeppelinLenni ZeppelinPřed 3 měsíci
  • 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

    Sci-DIYSci-DIYPřed 4 měsíci
    • @gorak9000 thank you. I tried both ways around (16 and 8 MHz) - same results. Finally (desperately) I've changed value in rpm formula from 120 to 60. And now I have correct readings. Does someone understand why there was 120 in first place?

      Sci-DIYSci-DIYPřed 4 měsíci
    • If you're using the same hardware and the same code, the thing I'd check is the board clock setting in Arduino - make sure it actually matches the crystal on the Arduino board. After you pick Arduino Pro Mini from the board selection in Arduino, the next item on the menu Processor, you have to select whether you have a 16MHz or 8MHz board (and 3.3V or 5V board) - you have 16MHz selected in the software when you actually have an 8MHz board, so the code thinks each tick of the timer is half as long as it actually is, which is why you get 2x the speed. Change that setting, re-upload the sketch, should work!

      gorak9000gorak9000Před 4 měsíci
  • 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?

    karl haxthausenkarl haxthausenPřed 4 měsíci
  • 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!

    Abdullah KırmızıyüzAbdullah KırmızıyüzPřed 4 měsíci
  • 3:12 Du soll test das Messteil nicht seitlich dranhalten, sondern direkt oben drauf, desswegen hat es eine Vertiefung an der Oberseite.😂😂

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

    Khuddam e Mah'di ATFSKhuddam e Mah'di ATFSPřed 4 měsíci
  • my arduino ide freezes wihle uploading your code unfortunalty i cant find the fehler

    MilanMilanPřed 4 měsíci
  • 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?

    Dejan PetrovićDejan PetrovićPřed 4 měsíci
  • i suggest that you STICK with projects that do Not involve mechanical physics. googletranslate

    David DavidsDavid DavidsPřed 4 měsíci
  • did one of those adapters have a rubber, CONCAVE end. if So, THAT should have been pressed against the END of the motor shaft.!!!!!!

    David DavidsDavid DavidsPřed 4 měsíci
  • 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

    David DavidsDavid DavidsPřed 4 měsíci
  • since your testing methods were FLAWED, so too is your opinion of this tach.

    David DavidsDavid DavidsPřed 4 měsíci
  • at 4:06, same On the motor SHAFT issue.

    David DavidsDavid DavidsPřed 4 měsíci
  • at 3:38, this a GEARMOTOR, not a slow motor.

    David DavidsDavid DavidsPřed 4 měsíci
  • 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

    David DavidsDavid DavidsPřed 4 měsíci
  • ummm. 'white tape' ???? REFLECTIVE tape !!!!

    David DavidsDavid DavidsPřed 4 měsíci
  • Urmom

    hoobly dooblyhoobly dooblyPřed 5 měsíci
  • Buy

    Ismael Dos SantosIsmael Dos SantosPřed 5 měsíci
  • scott: SPONSORS JLCPCB BUT doesn't use their pcb but you can send the scematic as a gerber and order a pcb

    mango- guymango- guyPřed 5 měsíci
  • I think your video is great! I can tinker with Arduino. I draw with the elek. CAD and then I can order JLCPCB. Perfect! 👍😉😊

    Krah Basteln HobbyKrah Basteln HobbyPřed 5 měsíci
  • 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?

    WolfinWolfinPřed 5 měsíci
  • 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

    Nick's StuffNick's StuffPřed 5 měsíci
  • 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.

    JTLJTLPřed 5 měsíci
    • Tried it. Did not work

      GreatScott!GreatScott!Před 5 měsíci
  • 2^16 = 65536

    John USPJohn USPPřed 5 měsíci
  • Simple is best

    Vignesh RVignesh RPřed 5 měsíci
  • You put more than $9 of labor into it though. You may not count the price of tools needed, but labor is valuable.

    joblessalexjoblessalexPřed 5 měsíci
  • DLY OR buy Arduino

    popattarapopattaraPřed 5 měsíci
  • I guessed your brushless rpm was 240 rpm.

    Algomarble racerAlgomarble racerPřed 5 měsíci
  • My ear is an rpm detector for high speeds.

    Algomarble racerAlgomarble racerPřed 5 měsíci
  • Next on DIY or Buy: The differential probe Would be nice to see GreatScott attempt to build one :)

    Hetchelle Tomikkō-nHetchelle Tomikkō-nPřed 6 měsíci
  • Question about the calculation - you wrote your divisor as "25 * 4", which is presumably 100fps video recording? But WHY '25 x 4' instead of just writing 100? (As every math teacher everywhere is fond of saying... show you work!)

    Canadian RocketboyCanadian RocketboyPřed 6 měsíci
  • DT-2234C, less than 9 €, works perfectly for me. Cheers !

    brainfornothingbrainfornothingPřed 6 měsíci
  • Thanks for the video and the tachometer project. I was doing experiments with PC-fans. And i wanted to know how to measure RPM correctly. And see if these sensors from AliExpress could do the job. So I bought a few of them, put one sticker on one of the blades of my 12 cm fan. The result was very dissapointing, the cheap sensor could not read this signal quick enough. Even not below a few hundred RPM (checked on scope via 3rd sensor wire). So these sensors are surely way to slow for this kind of RPM measurements. I bought a proper one (Voltcraft DT-10L laser tachometer, for about 62 euro's). This tachometer can measure up to 99999 RPM and works fine and precisely.

    Barend Jan van EijkBarend Jan van EijkPřed 6 měsíci
  • Not even 1 min in, so salty about the purchase it's obvious that DIY is better xD

    SpikeTheSpikerSpikeTheSpikerPřed 6 měsíci
  • I enjoy watching your videos and I don't argue with your project being more accurate than the HoldPeak, but I have to comment that the *title* is a bit misleading since you are comparing a single 3€ component, which requires a bunch of other parts adding up to about 20€, to a finished 29€ product ready to use.

    tornadokattornadokatPřed 6 měsíci
  • I wonder if there's something wrong with the timing circuit on the 29€ unit? Would be neat to do a follow-up with diagnostics if you can get inside the thing, shouldn't be too complicated since all it does is compare pulses to a clock. (Unless you returned it for some reason.)

    pauljs75pauljs75Před 6 měsíci
  • I used a Hall sensor to make my RPM counter it also works flawlessly

    Q RQ RPřed 6 měsíci
  • "Pretty much the same thing, just way more complicated." Basicly middle school to high school.

    stormy sauce!: byuutanestormy sauce!: byuutanePřed 6 měsíci
  • Putting a load on the motor with the physical tachometer will slow it down and reduce the reading...

    Nicholas RehmNicholas RehmPřed 6 měsíci
  • Very clever 🙏 thanks

    白兔阿白兔阿Před 6 měsíci
  • spell tachometer 5 times fast the fifth time : tacometer

    Jeffs HereJeffs HerePřed 6 měsíci
  • Hello @great Scott is it possible to make a vedio about *battery desulfater* is it a myth or fact

    neil Gneil GPřed 6 měsíci
  • why don't you make a li ion battery powered computer ups

    Unknown PersonUnknown PersonPřed 6 měsíci
  • Can you talk "reading power line communication"

    Tari OgoungaTari OgoungaPřed 6 měsíci
  • Make a video on making audio interface for XLR microphones,It difficult to make a good low noise phantom power with a good gain,make sure to try it out

    Unknown PersonUnknown PersonPřed 6 měsíci
  • 0:05 Wenn Deutsch kickt :D

    Mega FlohMega FlohPřed 6 měsíci
  • Can you make a video about how to use VGA output.

    GD TheuTrichGD TheuTrichPřed 6 měsíci
  • You know, I'm subscribed to your channel but I rarely see your videos anymore. Checking notifications. Right now I'm trying to figure out where is the best place to order computer components, M.boards, Processors, Where do you get best prices for AMD for example?

    Bad AliceBad AlicePřed 6 měsíci
  • Please make adjustable reng non contact tester

    Nikhil GadhariNikhil GadhariPřed 6 měsíci
  • Can you do AAA x4 battery replacement with li ion battery?

    william aquicewilliam aquicePřed 6 měsíci
  • can it be modified in any way and used as a Speedometer for my bicycle??

    MANISHMANISHPřed 6 měsíci
  • As always, great video! Short suggestion: Since you use the international language, you might want to also put out the (est.) dollar value for the viewers when mentioning a euro value? Keep up the good work! Weiter so!

    Jo NoybJo NoybPřed 6 měsíci
  • ADH Amplifier how it's work

    Technical Vigyan IndiaTechnical Vigyan IndiaPřed 6 měsíci
  • please tell me the battery specs you have used as the link is not working.

    Embedded GuruEmbedded GuruPřed 6 měsíci
  • Oh my god he is left-handed.... Mutant! :D

    xn0xn0Před 6 měsíci
  • It's surprising how many favorite CSworldrs of mine are from Germany. I'd really like to visit there some day.

    grovermaticgrovermaticPřed 6 měsíci
  • I love GreatScott Works...........by the way I want to measure engine rpm from my bike...how do I do it using arduino or any other solution?

    menuka udeshanamenuka udeshanaPřed 6 měsíci
  • why don't you try making different type of transistors

    Unknown PersonUnknown PersonPřed 6 měsíci
  • Hi can you convert a smart phone into drone flight controller

    Bittu Kumar Thakur{14}Bittu Kumar Thakur{14}Před 6 měsíci
    • Quite a few drones already have software/app remote controls, and some of them are app control only, no physical remotes

      bin chicken boibin chicken boiPřed 6 měsíci
  • You are using the Tachometer wrong... Thats why there are different values...

    VerärgertesSpielenVerärgertesSpielenPřed 6 měsíci
  • Please make a spy cemara

    Jatinder SinghJatinder SinghPřed 6 měsíci
  • Bro please make mobile signal jammer

  • how does your perfboard bridge so easily? it is very hard to bridge mine when i want to bridge

    MaxMaxPřed 6 měsíci
  • I wish i know how to code 😭

    John PhillipJohn PhillipPřed 6 měsíci
  • You are great, I will try this :)

    Mehmet uğurluMehmet uğurluPřed 6 měsíci
  • A year ago I had a similar project. I had quite the Problem with the accurate counting, because the Arduino was too fast and produced overcounting because the interrupt was triggered several times at the edge of the tape. I had to use a delay of some us to avoid double counting of rotations. I am rather surprised that your setup worked so well for you.

    Electricaly ChalangedElectricaly ChalangedPřed 6 měsíci
    • Hi, i'm currently working on the same kind of tachometer (using mega8 uC, LCD, and the same IR sensor). By inaccurate counting i assume its external interrupt triggers several times while the object passes only 1 time? while testing the IR sensor, i realized after i tried to wave my hand 1 time in front of the sensor, the interrupt count suddenly increments by 4! (and sometimes even 6 lol) this led me to assume that the output of the IR sensor itself is bouncing. (and i dont have oscilloscope to check this since i'm still a student) this issue is solved after adding some RC network to debounce it, and the IR sensor triggers the ext interrupt now correctly (for example i waved my hand 5 times in a fast manner, and the count increments exactly 5 counts) Hope this helps and I'm happy to accept any advice too, thanks~

      Yeyee _Gabriel_S_Yeyee _Gabriel_S_Před 5 měsíci
  • I want to make multi port usb charger which will take input from the laptop charger how I get start regarding a basic circuit

    Salman SayyedSalman SayyedPřed 6 měsíci
  • I just noticed he's left handed

    Make it easyMake it easyPřed 6 měsíci
  • Can you make episode: DIY or Buy voltage detector

    AvdićkoAvdićkoPřed 6 měsíci
  • Please make a 12v battery capacity tester with explaination

    Yameen AnsariYameen AnsariPřed 6 měsíci
  • I hope you read this. Please consider making a 3D printed 8th order bandpass speaker with a (hidden) 4.5 inch driver to 250-300Hz with port on same side as a 2.5 inch driver for the rest of frequency range and design a proper crossover for that design. We all learn about crossover eventually and now you can be authority and overcome previous mistake. We love your videos and your excellent efforts.

    Mr. Box ManMr. Box ManPřed 6 měsíci
  • Excellent video keep it up .

    Explore GadgetsExplore GadgetsPřed 6 měsíci
  • you use the contact thing completely wrong. no wonder you get such smoky reading

    Manus HolmManus HolmPřed 6 měsíci
  • First of all, Great video. Can You also make one for Mobile Signal Boosters please ?

    Thought ProcessThought ProcessPřed 6 měsíci
  • taco meter

    varun sreedharanvarun sreedharanPřed 6 měsíci
  • Its not turning, its executing.

    Panther PlatformPanther PlatformPřed 6 měsíci
  • Parabéns amigo

    Sobrevivente AlphaSobrevivente AlphaPřed 6 měsíci
  • 2^16 is 65536 ;)

    Róbert ÁgostonRóbert ÁgostonPřed 6 měsíci
  • Is good to use regulated 5v Transformer less power supply for microcontroller like AtTinyXx or same so..??

    GujaratiKanudo - (ગુજરાતી કાનુડો)GujaratiKanudo - (ગુજરાતી કાનુડો)Před 6 měsíci
  • can this ir sensor be used for higher rpms say over 3000??

    Gautham RaviGautham RaviPřed 6 měsíci
  • whats the programming language that you used!?

    acsel Ramirezacsel RamirezPřed 6 měsíci
  • where did you study electrics?

    xZuhnxZuhnPřed 6 měsíci
  • LoL it's good for education purpose but that sensor is in my cheap android phone(the sensor which turnoff the screen on call when it's near head) I'm gonna make an app and will send you in your mail

    Rahul GhoshRahul GhoshPřed 6 měsíci
    • Guess what play store already has such kind of rpm meter apps lol......cheers

      Rahul GhoshRahul GhoshPřed 6 měsíci
  • sincerely I got excited about this idea cause I think is the only one y can make without getting any extra parts.

    Kenneth LazoKenneth LazoPřed 6 měsíci
  • não da pra ajustar esses baratinhos que são vendidos ?

    Paulo HenriquePaulo HenriquePřed 6 měsíci
  • I have always loved your constructive approach to electronics and making things in general. you inspire me alot. keep up the great work Mr. Scott

    DelaliDelaliPřed 6 měsíci
  • "Хуле не уле" мне послышалось в речи :))))

    -SB--SB-Před 6 měsíci