3 ms·
It seems it might be better to create a current source using a BJT or darlington pair and a larger resistor attached to the base. That would take pressure off
by projektfu 6y ago
It seems it might be better to create a current source using a BJT or darlington pair and a larger resistor attached to the base. That would take pressure off the little GPIO pin and give you a consistent 20ma current, regardless of the resistance of the current loop.