Everyone needs a hardness tester.

[jdurand]

Great to see that you found my original post useful.

You may recall that in my PDF I stated that polling gave been results than using interrupts. For projects since I made the hardness tester I have used ESP32 boards in place of Arduinos. ESP32 is like an Arduino on steroids, they are many times faster. So if I was doing this project today I would try using interrupts on an ESP32 in place of polling on a Nano.

There's also the LGT8F328P boards. I rather like them, small, 4x faster than regular Nano, and CHEAP. I use the LArduinoISP programming pod for those with the Arduino IDE.



Ready made pod tiny, but you can also just program a Nano or something to work the same.