I know not to connect the Photodiode to pin 13 directly, I just had it like that as an example of what main components I will be using
I dont want to control each individual LED with drivers, I just want to control the whole set of them,
Ok, I looked at charlieplxing, but I dont see how that will help me, I am drawing 0.32Amps for each LED Matrix,
QuoteOk, I looked at charlieplxing, but I dont see how that will help me, I am drawing 0.32Amps for each LED Matrix, The point about a matrix is that you don't have all the LEDs on at the same time, you multiplex them so fast they look like they are on at the same time.Otherwise you need drivers to provide the current both sourcing and sinking. This will allow you to control a whole row at a time.You can not have full none multiplexed controll of each LED in a matrix. Tha act of wiring them up in a matrix means you have to multiplex them.
The base emitter junction of a transistor is just like a diode, it will conduct current. This will flow from the base through the emitter and out of the emitter and through the LED.If you labeled the transistors in that diagram perhaps we could talk specifics.The three LEDs shown as on, are on because 5V is being applied through a resistor through the base / emitter junction to all three LEDs. Why should they not be on?This is a good place to read up how transistors work.http://www.kpsec.freeuk.com/trancirc.htm
Remember that the lLED will always be powered if there is any current flowing through it. The way to make sure it is truly off is not to provide it with enough voltage to exceed it's turn on voltage.