Hello i have a Question i notice on some 4x4x4 led cubes they use transistors on the anodes side and and connected to the arduino but are using like 12v i was wondering something sense they put the cathode row in a digital pin wouldn't that burn out the arduino? useally i know the cathode goes to ground but it's not on ground its on a digital pin written to low. so i was wondering wouldn't that burn it out?
Joseph
yup, that would burn out the arduino, see: LED cube 4x4x4 - Do I need transistors? - LEDs and Multiplexing - Arduino Forum
josephchrzempiec:
Hello i have a Question i notice on some 4x4x4 led cubes they use transistors on the anodes side and and connected to the arduino but are using like 12v i was wondering something sense they put the cathode row in a digital pin
There are a lot of junk circuits on the Internet, yes.
josephchrzempiec:
wouldn't that burn out the arduino?
Maybe not instantly. It might survive long enough for them to put the circuit on the web.
i notice when i power up my cube I'm using 5v from the arduino looks dim but it's cool no transistors at allno resistors at all either.
josephchrzempiec:
it's cool no transistors at allno resistors at all either.
No transistors/resistors is a bad thing.
yeah i know just wanted to try it and see. 64 leds multiplexing each 16 leds on each row.
i end up putting resistors on it i just wanted to see if it worked without them being so many leds per row 16 of them at a time.