I added the last three LEDs to my 7x5 display awhile back, but didn't actually test them until this morning. One of them wasn't lighting up. Took a close look and I can see what a poor solder job I did. The flying wire wasn't even touching the next on in the row. Have to fix that next time I get the iron out.

I want to try out the bidirection LED thing using this board. I want to read all seven LEDs in the rightmost column and see which one you are touching. For starters I'll just light up the whole row, so you can see a moving bar of lights when you run it. Eventually you could use this to set a value: the center line is no change, each row higher means increase faster, each row lower means decrease faster. Or, from top to bottom: +++ ++ + 0 - -- ---.

To get started I created a new project in Atmel Studio for the Tiny2313 chip. This time around I'm not using the overflow interrupt for timer0, I'm just polling the overflow flag and resetting it. It didn't take long to get a row-strobe test pattern running. I've added sockets for ISP to the board, so I can just build the software and then upload it without disconnecting anything or removing the chip from the board. Sure makes things easier.

I should save off a copy of the current firmware, it's nice to have a test pattern to make sure all the LEDs are lighting up. That's how I found the bad solder joint this morning.

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I'm using emacs again and wanted to find a way to link in the Beagle disk indexer. One google minute later I found Piotr's Page with a nice bit of elisp.

  (defun beagle ()
    (interactive)
    (let ((locate-command "locate-beagle"))
      (call-interactively 'locate)))

where locate-beagle is a shell script:

#!/bin/sh
beagle-query $@ | sed 's!^.*file://!!'

Not sure about my setup but I think I need to add beagled to my .xsession file.