The Arduino Sketch (code) uses the external interrupt (int 0) on Arduino’s digital pin 2 (D2). This is used to read the output pulses coming from the water flow sensor. When Arduino detects the pulse, ...

Interestingly, he uses the Arduino IDE mixed with native ESP-IDF APIs to get the best performance. Like most complex interrupt-driven software, [Ivan’s] code uses a two-stage interrupt strategy.

For those wanting to try this out, [stockyu] has included some example Arduino code for others to use. It’s an interesting take on a solution for a common problem, and puts very little load on ...

We'll outline the basics of the Arduino itself, what the crazy jumble of wires means, and then step through how to use other people's code and schematics to build your first electronics project ...