Measuring Tachometer output on Zybo

[vishav]

Hi,

I am using a 4 wire fan and my task is to measure the speed of the fan using the tachometer output of the fan. The tachometer output produces 2 cycles per revolution of the fan. Hence it is a square wave whose frequency varies with the speed of the fan. I have read some posts that it can be done by calling interrupt at the rising or falling edge and hence counting the number of pulses.

Does anyone have an idea how can implement this on Zybo board? Where should I input the tachometer output on the board? Which interrupts should I call for this operation? Any help would be appreciated.

Thanks & Regards

Vishav

[jpeyron]

Hi @vishav,

Here is a forum thread that has a project made for the zybo with gpio interrupts. This might be a good place to start.

thank you,

Jon

[vishav]

Hi @jpeyron,

Thanks for the reply but I am not sure if this is what I am looking for. I was following a document which explains the frequency measurement. This document is from digilent. Here is the link:

https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0ahUKEwirwu7jxaXaAhVO-qQKHTRRCJgQFghRMAQ&url=http%3A%2F%2Fwww.mrc.uidaho.edu%2Fmrc%2Fpeople%2Fjff%2F340%2F341%2Flabs%2Flab10%2Fproject10.pdf&usg=AOvVaw3auqR4Z1s_W5GgNw5djsSY

I understand the concept for the measurement of frequency now but I don't know how can I implement on zybo board. It would be very helpful if you can give any assistance on this.

 

Thanks & Regards

Vishav

[jpeyron]

Hi @vishav,

The is a good guide for measuring frequency on a PIC32 microcontroller. The process can be converted to a fpga. Here is an article Measure the time period/Frequency of an input Pulse that shows how to do something simular in vhdl.

thank you,

Jon