My sister is trying some LED art and i would like to help her, here is my first noob question.
I followed this guide here (the arduino teacher 4x4 matrix):
And wired all my led's the same way:
my LEDS (white 3mm 3v 20mA)
sorry for the grain factory samsung s3 mini. Sister took the camera out today.
Only hooked one row to debug.
So after the code is uploaded successfully, i see no light change, but when i MOVE pin 9 to GND then i see the light blinking and doing what the code wants, this is obviously not cool in a matrix since i want dynamic grounds for the persistence of vision thing.
why are my digital-cathode pins not pulling to ground?