Introduction: Useful AVR Dragon Modifications
More by the author:
About: I am an electrical engineer. I graduated from U of Waterloo. I used to work for Adafruit Industries as an EE. Now I work for Sony PlayStation as a EE.
I have a AVR Dragon. I didn't like a few aspects about it so I've decided to make some modifications to it.
The AVR Dragon has three connectors:
But the problem is that if I want to use JTAG, I can't leave another cable on the ISP connector because the two connectors are too close together. If I want to use ISP, I can't leave a cable in the JTAG or HVPROG connector. If I want to use HVPROG, I can't leave a cable in the ISP connector. This is annoying.
The solution is to make a monster cable that plugs into all three connectors at once. You need to find a 40 pin cable, such as one used for IDE hard drives. Divide the ribbon cable into JTAG, ISP, and HVPROG sections, and clamp on the appropriate sized IDC plug. To figure out how many wires per section, use your brain, JTAG is 5X2, so it needs 10 wires, so make a cut after the first 10 wires. Then you skip two wires because there is a small gap (exactly enough for 1X2 pins) between the JTAG and ISP connector, then the ISP connector needs 6 wires because it's 3X2, then skip another two wires for the gap between ISP and HVPROG, then there should be 20 wires left for HVPROG.
Use a red permanent marker to indicate pin one on each cable section.
The packaging box that the AVR Dragon arrives in is beautiful. I made two modifications to this box:
I cut a hole for a USB cable so I can keep the AVR Dragon inside this box all the time.
I added magnets to the rim of the box, by embedding small magnets into a chunk of plastic first, and then putting that chunk of plastic under the cardboard. I also inserted a sheet of steel into the lid of the box. Now the box stays shut magnetically.
The AVR Dragon has three connectors:
- 5X2 pin JTAG
- 3X2 pin ISP
- 10X2 pin HVPROG
But the problem is that if I want to use JTAG, I can't leave another cable on the ISP connector because the two connectors are too close together. If I want to use ISP, I can't leave a cable in the JTAG or HVPROG connector. If I want to use HVPROG, I can't leave a cable in the ISP connector. This is annoying.
The solution is to make a monster cable that plugs into all three connectors at once. You need to find a 40 pin cable, such as one used for IDE hard drives. Divide the ribbon cable into JTAG, ISP, and HVPROG sections, and clamp on the appropriate sized IDC plug. To figure out how many wires per section, use your brain, JTAG is 5X2, so it needs 10 wires, so make a cut after the first 10 wires. Then you skip two wires because there is a small gap (exactly enough for 1X2 pins) between the JTAG and ISP connector, then the ISP connector needs 6 wires because it's 3X2, then skip another two wires for the gap between ISP and HVPROG, then there should be 20 wires left for HVPROG.
Use a red permanent marker to indicate pin one on each cable section.
The packaging box that the AVR Dragon arrives in is beautiful. I made two modifications to this box:
I cut a hole for a USB cable so I can keep the AVR Dragon inside this box all the time.
I added magnets to the rim of the box, by embedding small magnets into a chunk of plastic first, and then putting that chunk of plastic under the cardboard. I also inserted a sheet of steel into the lid of the box. Now the box stays shut magnetically.
Participated in the
Electronics Tips and Tricks
