i need to use a GPIO pin to test whether an LED is on/off. the LED only has 2v power which is not enough for my digital input (3.3v) so i would like to use a transistor to amplify the voltage from 2v to 3.3v.
currently i have tried it with an NPN transistor and a 10k resistor on the base (no others). with this set up only 0.8 volts of the 3.3v collector voltage comes through at the emitter. the base voltage also drops from 2v to 1.6 somehow.. how would i set up the transistor as a voltage amplifier? or how else could i read these signals?
i am using a beaglebone black.