We all have projects from yesteryear that we wish had been documented better. [EjaadTech] is fighting back by creating a project page about a tachometer he built 3 years ago while in college. He’s done a great write-up documenting all the steps from bread-boarding to testing to finished project. All of the code necessary for this tachometer is available too, just in case you’d like to make one yourself.
At the heart of the project is an AVR ATMega8 chip that performs the calculations and controls the LCD output screen that displays both the immediate RPM as well as the average. To hold everything together, [EjaadTech] etched his own custom PCB board that we must say looks pretty good. In addition to holding all the necessary components, there is also an ISP connector for programming and re-programming.
There are two attachment options for sensing the RPM. One is a beam-break style where the IR emitter is on one side of the object and the receiver is on the other. This type of sensor would work well with something like a fan, where the blades would break the IR beam as they passed by. Then other attachment has the IR emitter and receiver on one board mounted next to each other. The emitter continually sends out a signal and the receiver counts how often it sees a reflection. This works for rotating objects such as shafts where there would not be a regular break in the IR beam. For this reflective-based setup to work there would have to be a small piece of reflective tape on the shaft providing a once-per-revolution reflection point. Notice the use of female headers to block any stray IR beams from causing an inaccurate reading… simple and effective.
8 thoughts on “Fantastic Tach Is Strangely Called Tachtastic”
What, not Fantastach? I am disappoint.
it would have sounded like Fanta….
and I was young back then… :)
I like how he has almost “filled” the pcb to the brim with tracks. It almost looks artful.
this is one of those PCBs I am still quite proud of and show to my juniors when telling em how to design/make PCBs… but is that wrong..?? filling the PCB up..?
wasn’t sure if hackaday would post the project…. I hope I will have the energy in the monring to upload another one.. I have a few working and many FAILs from my engineering days and even some from recent days…
Lots of projects and pics.
THANKS for posting this… encouraging me to post more
I suggest you do 2 things . 1/Load a picture that is focused of it counting revolutions. 2/ Move from a site that insists you register to post comments.
Reason being if you make something you must show it works .I didn’t see a rev count anywhere. With the signing up its just becoming a chore to join all these different sites as you surf and its not necessary at all , just a grab of time and data just to say “we made it” Look at Hackaday , they don’t demand it nor do they insist you log in with Google or some god awful invasive mob.
I never registered to post on this site. I use my WordPress account to post here.
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