Entries from September 2007 ↓

I wrote this article a few months ago and it generated a lot of interest. It describes how to decode IR signals just using your electric guitar, a wav editor, and your eyeballs.

After my last experiment on POV, I realized that I needed some external hardware to burn a bootloader onto a new Atmega168 for my Arduino board. I decided to build a Parallel-Programmer since it seemed to be the easiest. Here is what you need (mostly):

1. soldering iron
2. DB25 connector
3. 1 x 220-Ohm resistor
4. 2 x 470-Ohm resistor
5. some hookup wire
6. DB25 housing (optional)
7. 6-pin header (or 2 3-pin headers)
8. some epoxy (optional)
9. electrical tape

I got these products from SparkFun Electronics for pretty cheap but you could get them just as easily at your local electronics store, unless you don’t have one, like me:

• 1 x 25 Pin Parallel DB25 Housing (SKU#: PRT-08286) = $1.95
• 1 x 25 Pin Male Solder Cup DB25 (SKU#: PRT-08287) = $0.95

After you got all your parts, heat up your soldering iron and secure the DB25 connector. Then solder everything as described here and shown here:

I twisted up the wires and put together the housing. I had a lot of extra screws and parts (it still all fit though).

I didn’t pay attention to what was coming from where when I twisted up the wires; so, I used this opportunity to use the continuity function on my multi-meter checking each connection and mapping which pin is connected to which wire. This ended up helping me ensure that each connection was mapped correctly and that there were no cold-solder joints.

After this I needed to connect a 6-pin header. Being that these are hard to find, I grabbed 2 3-pin headers and shaved them flat like so:

Next, put the header on one side of the arduino ICSP pins and apply a little epoxy on the inside.

Place the other header on the ICSP pins. Make sure not to glue them to the ICSP pins!

Let it dry, pull it off, and wrap it with some tape.

To connect it to the DB-25, follow the schematic on this link. Pin 1 is indicated on the PCB of the arduino board. Make sure you get it right.

As for the software side, you can use either UISP or avrdude. I would highly recommend avrdude especially considering many others have used it to upload the arduino bootloader. You need to get the right fuse settings and etc. Check out Lady Ada’s forums or the arduino playground for help. Or e-mail me if you really can’t figure it out.