25 uOhm Shunt resistor

[pioioTwo]

its possible mensure using 25uohm shunt resistor

[nathancheek]

Hi, do you mean 25 microohms or 25 milliohms? It should work fine with 25 milliohms. The library wasn't particularly written with microohm-level shunt resistance in mind, although with a high enough maxBusAmps value, I think it might work.

For very extreme values, you should look at lines such as the following, to make sure a useful value is still calculated:

INA220/src/INA220.cpp

Line 26 in e6f83c1

this->calibrationRegister = (uint64_t)409600000 / ((uint64_t)this->current_LSB * (uint64_t)microOhmR / (uint64_t)100000); // Compute calibration register

For example, if you passed in values such as maxBusAmps=5 and microOhmR=25, that line will calculate a large value which can't fit in the 16-bit calibrationRegister. But passing in a more reasonable maxBusAmps=1000 would avoid that issue.