I have 3 pairs of LEDs (Red, Green, Blue) coupled to 3 photodiodes.
I'm using a 5 volt reg to supply the 3 LED's independantly from an Aruduino board. I wanted to supply them separately but use the Aref when I use the analog inputs from the Photodiodes mounted opposite the LEDs
I just noticed that when I connect the Aref jumper from the 78L05 Voltage regulator on the LED board the Arduino board power LED lights up too. I did not expect that to happen.
I have not yet plugged the USB cable from the Arduino into the computer. I know I should preload the Aref instruction in the sketch. I just wish to double check before plugging into the UBS port... If I do then it will connect a 5 volt supply from the USB port. Do you know if that is OK?