ESP32 Pulse Counter

This video shows off a new pulsecnt module for the ESP32 NodeMCU firmware. The pulsecnt library handles sophisticated and automatic pulse counting using the built-in hardware on ESP32. The pulsecnt library gives you a means to not rely on GPIO triggers to do your pulse counting and instead offload the work to independent hardware. You gain the ability to count pulses up to 80Mhz (speed of APB clock).
You can get a callback to Lua when different counting thresholds are reached, or when upper or lower counting limits are hit. You can count pulses on all GPIO ports. There is also a way to provide a control GPIO for ignoring or decrementing pulses when the control signal is high or low.
The Github repo for the pulsecnt library is at github.com/chi...
Example code for different types of pulse counter implementations is available as Gists on Github.
Example Pulse Counter for 1 channel with no control gpio
gist.github.co...
Example Pulse Counter for hall effect sensor plus 1 push button to control direction of count
gist.github.co...
Example Pulse Counter for 1 channel for polling pulse count (no callback)
gist.github.co...

[@browaruspierogus2182]

Hardware pulse counter comes with esp-idf examples. Very easy to use

[@JohnLauerGplus]

I found it was confusing how there was one unit, two channels, four gpio ports (2 pulse in, 2 control), and a high/low limit for each channel, but in the callback you could never know which channel's high/low limit triggered the callback, rather all you know is that a high/low limit was triggered. You can ultimately deduce that info so not a big deal, but took a bit to wrap my head around their approach.

[@ivorypei3649]

Great video, John Lauer!

[@dalvrzx]

Hi! Thanks for the video. How many pulse counters can you use at the same time?

[@JohnLauerGplus]

nodemcu.readthedocs.io/en/dev-esp32/modules/pulsecnt/ are the docs now published into the main esp32 repo. You'll see the docs for pulsecnt.create(unit, callbackOnEvents) and that unit can be 0 thru 7.

[@dalvrzx]

@@JohnLauerGplus great! thank you for such a quick reply!

[@fransmulder9877]

Hi John, Yes it is confusing with 4GPIO pins for one channel. I couldn't finf which GPIO pins allocate to which Unit or alternatively how to allocate a Unit to a set of GPIO pins. Can you give a hint where to find this? Frans

[@JohnLauerGplus]

This library is now in the NodeMCU ESP32 docs, so I suggest you go to that as I created tons of example code.

[@CHEFDEPARIS]

Hi, Greatings from Paris! How big do you think 3D printing is gonna be?

[@jak_k]

I really think you need to get rid of the handheld camera. Otherwise nice vid.

[@JohnLauerGplus]

Yeah, it's hard to find the time to make these videos though, so I side on showing good content over spending a bunch of time on the setup like a camera holder, otherwise I'd just never publish niche stuff like this. There's not very many people looking to understand the ESP32 pulse counter hardware.

[@jak_k]

@@JohnLauerGplus Yeah I imagine editing would take 3-4 times longer than a video runs, but "if you build it they will come". anyway thanks for taking the trouble to share what you have learnt.

[@jak_k]

Which onscreen oscilloscope do you use? Thanks

[@JohnLauerGplus]

It's the MSO-28 scope. It's super handy to not be tied to your main work desk to scope stuff up. Not as cheap as I think a USB scope should be, but I gotta believe there's cheaper stuff out there these days.

[@aragornale]

Where can I get de source code. Thank you

[@JohnLauerGplus]

It's built into the NodeMCU ESP32 firmware now. Just make sure when you build the firmware you include the pulsecnt module.

[@aragornale]

@@JohnLauerGplus Thanks....i was talking abaout the source code. But i have watched in youtube smartphone, it doesnt show the links for github. Now i´m have seen in normal machine, and found the github source code in comments. Thanks again.