large dot matrix and arduino lag is it fast enough?

Projects General Guidance
1

Hi,

Before I get too carried away on a project I just wanted to get some advice on weather or not its actually going to work. I will be able to do it but dont know if the arduino will be able to handle all the info going to it.

I want to put a webcam image onto a dot matrix display that is 56 x 40 pixels.

Will the arduino be able to handle this? I will be making this with a dozen shift registers and work out to about 2300 LEDs. processing will be handeling the image and sending the info to arduino.

Will this be too laggy? there will be a little bit on movement but not everything will be changing all the time so to speed it up i was going to program it so that it would only update the changes.

Thanks,
Nick

2

Some basic calcualtions:

If you drive the leds individually a bitrate of 32kb/s will give you about 15 frames/s and you have 26µs per bit. That should be still doable if the data transfer and decoding of the video is fast and simple and if you don't use digitalWrite(). If you can afford to set up a whole I/O register for data and send out 8 bits in parallel, things get easier, because 1 port write will drive 8 bits at the same time, thus giving you 200µs per port write to do the work.

This assumes the LED will just be on/off and no dimming. If you need to have PWM control over all LED, I doubt things will work out.

Korman