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Topic: Challenging Atmel users: to use a serial LED display, PIC based (Read 863 times) previous topic - next topic

takao21106

I have designed these displays, using various prototypes, because it was
way too much effort to wire the display drive again and again.
After a while, I was even doing away with the display drive.

I made very small PCBs, containing one 0.36inch 4-digit LED display,
one PIC16f54 TSSOP, and one 22uH coil.

They work relieably and nothing gets hot or burns out.
Voltage can be lowered from 5 volts down to 3 volts,
where you get average brightness.

It is not easy to use them, however.
Since all port bits are used for the display drive, a clocking scheme is
used where every second display phase is actually blank.

The master controller must monitor a 1-0-1 transition for one
sink line, and then start to send data serially.

There are also some external resistors required as well a diode,
the voltage levels are not clear enough due to the display drive.

But, it is possible! I made a PCB containing one master 16f54,
and two slave displays.

Would you be interested to try using these displays for Arduino?
There is no reason I can see why they won't be compatible.

I do not rely on the fact if you are interested for these displays or not,
but I am also browsing this forum.
youtube.com/watch?v=YwFwE2yx6RY
http://www.flickr.com/photos/yakone22/sets/72157629325847431/

I could sell programmed display boards for about $6 or so, if I wanted to.

But I think, for some users having a hardware serial port on the display
PCBs would be better. As well these displays can not be cascaded,
if you want two displays you need 6 i/o lines.

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