Peter Dannegger wrote:
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>Did it Work well ?
>I think, it must flicker, since there is no synchronization
>input for the internal multiplex frequency.
That was the very tricky part. It didn't flicker if you held enough charge on an electrolytic to "feed" the opto triac until the refresh.




"Putting all the rows on the digit drivers and the segments to the columns ?"

>It depends, which the anodes and which the cathodes.
>For the software its only 7 registers with 5 bits
>or 5 registers with 7 bits (5*7 matrix).
>The last version give a little more brightness
>and faster transfer (only 5 bytes), thats all.

You need one device per two characters then ?

"...and you would need to switch external transistors to handle the necessary voltage drops"

>Only on very big displays.

..but with 7 leds firing, you will need 9V to drive them which exceeds the device handling capability.