Normally I would drive a current between a GPIO output at 3.3V (HIGH) and GND, for example to light a LED (with a resistor included of course). I am now wondering if it is safe to drive the current in reverse; between GPIO output at 0V (LOW) and the 3.3V supply.
I have tried to find an answer but have not been able to find a definitive one. Some people tend to even add diods to stop reverse currents. Others seem to think it should be fine. I could experiment but I would not like to gamble and risk my PI...
Background: I need to drive a bunch of segmented LEDs with common anode connections. I intend to drive one LED at a time directly with the GPIO current. To toggle them I must therefore toggle the connection to ground. One option is to use a NPN transistor for each line. A much simpler possibility, however, is the one above.