I just wanted to say thanks for making such a great project/kit! About a year ago I got a tackle box of misc. electronic parts from ebay, and one of the many things in it was 2 packages of parts for what appears to be a Devry microcontroller lab interface kit (2 bags of parts and list no instructions), including two of the Kingbright PSC08-11EWA displays. I was looking for project to use them on, and also looking for something to get started in microcontrollers and now I have a useful project for both! I got my USBTinyusbISCP kit from you and as soon I get it put together and get a battery holder of the right type, I'll be putting this together and letting you know how it turns out. I hope to be building a few of you projects soon, and just wanted to thank you for running such a great site!

Just wanted to give an update, I sat down last night to build my first reader board, and since I have the grey front Kingsbright LED I made sure to get the older instructions, but checked the forums and got the 2.1 firmware so that AVRDUDE wouldn't have issues. Went thru and soldered it up with a socket, the chip programmed fine, plugged it, turned it on......and nothing. Hmmm double check connections, check the chip, nothing. Grrrrr. Put it aside until morning cause it was getting pretty late when I finished triple checking everything. This morning I decided to take my second Kingsbright PSC08-11EWA and breadboard it for testing purposes, yep yep everything checks, wired according to instructions, firmware is correct, common anode is set in compile options, nothing. Check battery supply, that's fine plenty of power, chip is fine, did I screw up the LED? Pull it out get out my bread board with my testing circuit on it, hmmm put the plus on pin 11, touch the negative to any other pin nothing. Switch test clips, and we have LIGHT! Wait a minute, where's that data sheet I downloaded, I know it said it had a common pin......... ahhh cathode, but it comes in both common anode AND common cathode! D'OH! so go back to breadboard A, change the common pin from positive to ground, plug in try again, when it lights up every segment of the LED, smack forehead, re compile chip again with out common anode switch. and VIOLA! Working Microreader! Now i just have to desolder the socket from the first one to re wire it correctly. The moral of the story, don't assume, check the datasheet against the tech data of the project first to make sure you have every thing the same, and check for minor variations like common anode or cathode.

Great-- score one point for leaving a polarity switch in the code base.

Both polarities are certainly out there; you can usually tell which is which if you (1) can read the part number and (2) have the datasheet.

Yes, sadly I was relying on my memory of the fact that months ago when I got them, I looked at the data sheet and used my test bed to determine that yes it did have one pin that was a common, but sadly the part number on the LED and the datasheet do not differentiate between common anode or cathode. And i just assumed it was the same as in the V1.0 of the Micro-readerboard. But then I can't complain as I got them originally in my big box of ebay junk I bought, so I was lucky to have any alphanumeric displays I could use at all.

And you deserve more points for the polarity switch in the code, as I'm sure it will come in handy once I figure out the pins for some the other displays I now have (grab bags can be fun!) I really need to go sign up for the TGIMBOEJ so I can share.