8X8 RGB smooth led display Binary Code Modulation possible?

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Hello,

I want to make an 8 by 8 rgb led screen and was wondering if a 20MHz avr would be fast enough. The idea is to read data from SD card and use binary code modulation (BCM) as described in http://www.batsocks.co.uk/readme/art_bcm_1.htm to update the display. I am hoping to get 10 - 24 fps (smooth movement) and no flickering. So say I aim for 20 fps and 10 BCM cycles per frame at 8 bit resolution. Thus to update the 4 ports controlling the leds and read data from sd card ill have 20 MHz / (20*10*8 ) = 12500 cycles. Is it realistic to do all that in so few cycles? Also I have not used BCM before, how many BCM cycles is required for no flickering?

Thanks in advance
Luco

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Quote:
So say I aim for 20 fps and 10 BCM cycles per frame at 8 bit resolution. Thus to update the 4 ports controlling the leds and read data from sd card ill have 20 MHz / (20*10*8 ) = 12500 cycles.
It is not that simple. The number of clock cycles between the port updates is not constant. With a 8 bit resolution you have 8 different numbers of clocks. For (approx) 200 Hz BCM frequency and 20 MHz clock frequency they are:
390, 780, 1560, 3120, 6240, 12480, 24960, and 49920.

Stefan Ernst