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Tuesday, 17. June 2008
Hello 5x7 Style

Wrote a new firmware for the 5x7 display. Now it scrolls out 'hello' over and over again. I'm running it on a solar panel, so it wakes up with the sun and runs all day long.

When I built the LED matrix I put resistors on the five columns. I'm starting to think it was a mistake. I like to light up a whole block at a time, and it makes sense to turn one row on at a time instead of one LED at a time. So if I had put in seven instead of five resistors I could have a five column refresh cycle instead of a seven row cycle.

The bitmaps for the characters are stored row-by-row. That way I can just load a byte from program memory and use it unprocessed to light the LEDs.

I might set the display sideways and then scroll it right to left. That would give me room for two 3x5 characters.

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5487 days of detection
mod: 12/3/08 5:42 AM

days of detection

... PMOG
... ideas
... brain hurts
... weblo

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Biography

Randall Bohn lives in Orem, Utah, USA. He works as a Software Quality Engineer. He is a big fan of the AVR line of microcontrollers. He has been in the computer industry since 1989. Randall is married and has three children.

rsbohn can be reached via gmail.com.


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