High Speed Counter

Hardware
1

Hi
I am planning for my wind speed project. I need to read a pulse frequency from a rotation counter, but I have done some bench testing using a function generator & the node-red-contrib-frequency-meter node, and it seems to top out at about 20Hz. This seems to equate to approx 25-30mph, which isnt quite enough.

Any ideas as to what I could do instead ? Is there a HAT with a counter ?
Needs to be simple, I'm only an engineer :wink:
Cheers.

2

Node red isn't really designed for that sort of work (counting rapid pulses on an input). I think you need to use a hardware counter or frequency meter to do that, as you have suggested. This may not be the best place to ask about Pi add-ons, though someone may be able to suggest something.

3

Thanks Colin. Yes, I agree, I wasnt hugely surprised tbh but always worth a go ! I am thinking someone must have written something that does the counting outside of node red, in a faster envirinment, then presents it as figure to Node Red. All I can do it count the GPI as it is presented, then maths it. I would like to avoid a chip if poss as my electronics is a bit rusty !

4

Googling for pi hat counter gives lots of hits, though it would probably be much cheaper to use an ESP device or an Arduino or similar.

5

I actaully didnt have too much success looking for HATs. Would an Arduino counter have a high frequency ability then? How would I send data between the 2, could I do via MQTT, I just worked out how that works :slight_smile:

6

Wouldn't this do it?

I don't know about the capabilities of the devices to count, just making suggestions for research. I believe Arduino (which I havn't use) usually connect via serial and the ESP (which I have) via wifi and MQTT.

As I said this may not be the best place to ask about this unless someone here happens to have done something similar (a counter I mean).

7

Here's a link to an article on the ESP Easy forum. It sounds like someone has managed 65Hz using the Generic - Pulse counter within ESP Easy.

https://www.letscontrolit.com/forum/viewtopic.php?f=6&t=3476&p=18559&hilit=pulse+counter+speed#p18559

9

Thanks @dynamicdave for this, but it looks a little too involved for me, hoping to find something a bit simpler.

10

Thanks @Colin , I like the look of that & I have played with 1-wire also. Little steep on price tho.

11

The easy way is often not the cheapest.
There may be other options though, maybe try a Pi forum.

12

@Colin thanks. I will keep hunting, I may have to dig out an old Arduino, pretty sure I had one with a counter on, just not sure of the performance.

13

Maybe this Arduino library could do it? https://www.pjrc.com/teensy/td_libs_FreqCount.html

14

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