It was pointless to even glance around before unleashing a rivulet of colorful language. Nobody was near enough to hear my complaint. Fortunately. Another chip had been bricked by my careless use of PonyProg, and unlike the two recent DIP Atmega168s...this one was an Atmega128, mounted in my favorite development board from Olimex. The madness had to end. For the third time I had reset a chip to use its low speed internal oscillator, making it too slow for ICSP access. These micro controllers are so small, they don't even make good paperweights.
It was time to buy a better programmer. Something USB based that I could use directly from AVR studio. After finding the AVR Dragon, I thought my problems were solved. The Dragon does ICSP, JTAG, DebugWire, and Parallel\High Voltage programming. All for $50. What else could I possibly need?
Well...ICSP wires would have been nice. As it turns out, the Dragon is the barest of the bare. After several attempts to get the finicky Dragon to program my target board, I gave up in disgust. The problem might have been the ICSP adapter cable I hacked together. It might have been a problem with the Dragon. Finally, at the peak of my irritation, I bought an STK500 compatible USB programmer from the Ukraine. For another $50.
The injustice of having bought the Dragon but never having used it really bothered me. I had a small collection of micro controllers that could be recovered if only I could figure out the device. Finally, salvation arrived in the form of an RSS feed from AVR Freaks. A company called ECROS Technology had invented something for Dragon challenged folks such as myself. It is called the Dragon Rider. The basic kit is economically priced at only $23.95 plus shipping. I didn't even pause before whipping out my VeriSign dongle, signing into PayPal, and ordering one. It arrived in only two days.
Now, for the amount of money I had spent...I might as well have bought an STK500. That's essentially what the Dragon Rider\Dragon combo becomes. Except that the STK500 is much used and documented. Not so with the Dragon Rider (although ECROS has recently come out with an improved manual). After soldering the parts onto the board, I mounted a dead 168, set the jumpers, and tried to recover the chip using high voltage programming. Failure. The Dragon spewed its typical nonsensical errors at me. Were I not a packrat, I would have eaten the $80 investment and thrown the thing away. Luckily, I did not.
Two evenings ago, bolstered by success on some other projects, I revisited the Dragon\Dragon Rider. I re-read the Dragon docs and stumbled across an ominous warning: "Your Dragon will spew nonsensical warnings at you any time it does not detect a target voltage!" (or something to that effect). The Dragon Rider, as I hinted above, is not documented well (yet). Using the new and improved docs I mentioned above, I realized that since I was not using a sub-regulator on the board, I needed to jumper power directly from the Dragon to the target on the Dragon Rider by adding a wire where the regulator would have been. Voila! ICSP worked on a perfectly good chip. After adding a shunt to get clock from the Dragon, and adjusting the board jumpers and cables, I managed to get high voltage programming working as well.
Now that the Dragon Rider is better documented, and it saved my AVR Dragon from certain doom, I find myself...grateful. The board has room for everything on it. External power, max232, buttons, LEDS, an LCD, and a complete set of port headers for multiple targets. In the future, I would easily consider purchasing another one so that I can keep two projects going at the same time.
Is the Dragon Rider\Dragon combo a good value if you only need an ICSP programmer? No. With a little searching, you can find an ICSP board that does UART debugging, ICSP programming, and supplies target power for a reasonable price-all via a single USB connection. If, however, you need advanced debugging or high voltage programming, the Dragon may be for you. If you do buy a Dragon, you can save yourself a lot of time and headache by purchasing a Dragon Rider as well.