[avrdude-dev] Patches to support XBee Series 2 Over-The-Air flashing with avrdude

[David Sainty]

Hi AVR dudes,

I have developed a solution for flashing AVR devices via XBee Series 2 
Over-The-Air with avrdude (with no extra hardware, just a matching 
bootloader on the AVR).

The avrdude side requires a new "xbee" programmer type, which is 
essentially the Arduino module (as used with optiboot), but with the I/O 
streams encapsulated in a packet-based protocol delivered over XBee's 
API, and XBee GPIO pin toggling to perform the hard reset. The code is 
just a single xbee.c/xbee.h, with associated changes to register the new 
programmer type, so it's very self-contained.

The bootloader is an extension of optiboot, fits [pretty snugly!] in 
1kB, and auto-detects whether the standard "arduino" (~STK500v1) or 
"xbee" protocol is in use.  I.e. the bootloader can be flashed via 
standard unmodified avrdude (at a reduced baud rate, XBee defaults to 
9600bps) or flashed OTA by avrdude with the new "xbee" programmer type.

Over-The-Air it takes around 3 minutes to flash around 20kB, and a 
comparable time to verify.  I'm personally thrilled it's so fast, I 
would have been excited even if it was an order of magnitude slower than 
that :)

I'd like to contribute the avrdude code into the base tree, what is the 
process for doing that?  I would be willing to join the developer team 
in order to maintain the module.

Thanks,

Dave

---------------------------

Example OTA flash to the device with Zigbee 64-bit address 
0013a200408b42a4, via a second XBee device on serial port /dev/ttyUSB0 
attached to the same Zigbee network (shared encryption keys etc).


avrdude -c xbee -P 0013a200408b42a4@/dev/ttyUSB0  -p m328p -U 
"flash:w:frontGateLight.hex"

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.20s

avrdude: Device signature = 0x1e950f
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be 
performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "frontGateLight.hex"
avrdude: input file frontGateLight.hex auto detected as Intel Hex
avrdude: writing flash (19418 bytes):

Writing | ################################################## | 100% 174.63s

avrdude: 19418 bytes of flash written
avrdude: verifying flash memory against frontGateLight.hex:
avrdude: load data flash data from input file frontGateLight.hex:
avrdude: input file frontGateLight.hex auto detected as Intel Hex
avrdude: input file frontGateLight.hex contains 19418 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 151.56s

avrdude: verifying ...
avrdude: 19418 bytes of flash verified

avrdude: safemode: Fuses OK (E:00, H:00, L:00)

avrdude done.  Thank you.