AVR Bus Pirate Patch

The bus pirate is an awesome little device. It can also work as an ISP programmer for AVRs. Avrdude even has support for it.

If you’re running a very slow clock (such as the ATTiny13A’s internal 128KHz clock option) the bus pirate will not be able to talk to it since the minimum speed for the bus pirate SPI is 30kHz. Martin Pander posted a patch to avrdude 5.11 which basically bit-bangs the SPI protocol and will go down as low as 5kHz, which should work with a slow 128kHz AVR clock. (ISP has a requirement that the SPI clock is 1/4 or less of the AVR clock). It basically adds the -x khz=# option to avrdude’s buspirate driver.

My experience with this patch is that it works, sort of. There seems to be some stability issues.

buspirate_khz.diff Magnifier - patch for avrdude 5.11 to add khz parameter to slow down ISP (7.53 KB) Andrew Kohlsmith, 04/17/2013 03:04 PM

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