So I was thinking of wiring up four 7-Segment displays through the Raspberry PI. I'd do that by multiplexing each of them, and came across this: http://hackyourmind.org/public/images/display7seg_anim.gif
The thing is, I'm aware that I can draw (and sink) a max of 16 mA per GPIO pin. Therefore I can only have a max draw of 16mA for each segment correct? (assuming I don't use a transistor for each segment to draw power from the 5v rail). So, if I'm only drawing less than 16mA at any given time, do I need those transistors to switch the multiple displays on and off? Can't I wire each of the common anodes/cathodes directly from the GPIO pins and just switch them high and low to turn them on and off?
EDIT: I'm also pulsing each of the segments of each display so I don't need 7 resistors per diplay and can get along with just using one resistor on the common anode/cathode and keep the brightness across different digits (is there a better way to do this?)