I built a thermometer out of some very bright green LEDs that someone donated at the AHRC meeting and an Atmel AT-MEGA8. The AT-MEGA8 is WAY OVERKILL for this project. It runs a 4 MHZ and has 8K of flash. But I wanted to test out the Linux Atmel programming tool chain. I am hoping to build a sign for Annie's lemonade stand in a similar fashion.
| Qty | Description | Source |
|---|---|---|
| 1 | LM34 Temperature Sensor (degrees farenheit) | glitchbuster.com |
| 42 | Really bright LEDs | kind donation at AHRC meeting |
| 9 | 2N3904 NPN Transistors | Jameco |
| 1 | Atmel AT-MEGA 8 | Digikey |
| 1 | 4" x 9" sheet of Lexan | All Electronics |
Now, I'll bet you are going to ask me for the schematic next... (there is none.)
I had great difficulty getting the 'top' transistor to work for controlling which segment was active. I think there is something wrong there. When I described how I got it to work (adding a couple of diodes), some folks said that I shouldn't have had to do that.
The thermometer is with my step father right now. He's building a case for it.
