I am trying to understand how the common anode matrix works
here is what my setup looks like in LT spice and I will be trying to simulate it and get results such as power, current, and voltage.
so the common anodes are connected to a DC voltage, in this case I used +5 volts
and the RGB pins have to have PWM on it so that it knows when to turn on/off according to the duty cycle
can someone help me clarify on that, thanks alot of reading this.
What I think:
If one row is of LEDS is turned on, so 8 LEDS = 8X3 = 24 LEDS * 20mA = 480 mA needed to supply for 1 row? since 20 mA is usually for max brightness.
Do I use P=V*I to calculate power so 5 Vdc * I = power? what about the Voltage in the PWM?
480ma@5v is the max per column, and not really PWM, its the same as all LEDs on, 0ma with all LEDs off, and somewhere in between for PWM.
I have a test rig that uses 8 RGB LEDs, and I've hooked it up to an external power supply, because that sounds like too much current for the arduino.
Your diagram doesnt include any resistors, or IC's or other helpful info, but from what I can tell, controlling RGB LEDs with PWM is going to be limited with a common cathode setup, common anode setup doesnt seem to be as limiting in driving options.
well here is my hardware config, im just trying for a basic simulation in LT spice
im trying to simplify the panel so that I can observe voltage, current, and power waveforms.
So my question is, for a common anode matrix 8x8
do you hook up a voltage DC source at the anodes
and what do you hook up to the RGB pins.
for a simple simulation, I do not want to make the circuit from the chips im using for my project, i just want to simulate a simple 8x8 common anode matrix and understand the waveforms.
Depending on how you drive it you will need to supply power for a whole row or column when you multiplex it.
so the common anodes are connected to a DC voltage, in this case I used +5 volts
No that needs to be switched as well as the cathodes. There needs to be resistors in the cathodes or you need to drive the cathodes with a constant current drive.
Do you want brightness control over the matrix?
If so then it is a lot more tricky.
This project of mine in effect is an 8 by 8 matrix with brightness control, but with a fancy layout. http://www.thebox.myzen.co.uk/Hardware/Hexome.html