After reading a lot and a few questions answered in this forum, I managed to make my sensor working. It's a pressure transmitter (piezometer) which output 4-20mA (corresponds to 0-10m).
I did it this way:
My only issue now is that the signal is not super stable. It's not a big deal but during my tests, I'm not moving the sensor but the results can vary by 1 to 3 cm between each measurement. For each of them, I read the analog 10 times (with 200ms delay) and average them.
I would like to know if there's a way to make the signal more stable.
So 16mA = 10m i.e. 1.6mA/meter. At 250R this is 400mV per meter or 4mV per cm. You say you have an error of 1 ~ 3cm per measurement; this is 4 ~ 12mV. I congratulate you; that's a very good achievement for this simple setup!!
@Idahowalker Thanks for these interesting links. My goal here is to find a way, if possible, to stabilize the signal in my scheme before using these filters. I didn't know these libraries exist and I will definitely use them.