The $5 programmer-debugger
In my review of the Xiao Expansion Board, I praised the availability of the SWD signals but regretted the use of standard 0.1" pins instead of the secure SWD standard connector.
Why not use another Xiao board as a DAPLink programmer-debugger? DAPLink is an open-source initiative by mbed: it provides SWD and JTAG connections and reroutes the serial port.
The compact size of the Xiao makes it an ideal candidate. What's better than a Xiao to debug another Xiao?
The board was sampled by SeeedStudio.
On the software side, Seeed provides the Simple DAPLink application source code and binary plus ample documentation to read.
Once the correct parameters have been found and set, the Xiao DAPLink programmer-debugger works as expected. For example, the stock OpenOCD doesn't work well, but the Arduino version does.
The tests shown here were performed in command line.
How does this USD5 programmer-debugger compare with other solutions?
The Segger J-Link Edu mini is priced at less than USD20 but it comes with two big differences: the excellent Segger J-Link tool-suite and the responsive support through the Segger forum.
The USD5 programmer-debugger is therefore perfect to get a taste of debugging, before migrating to more seasoned solutions.
Posted: 18 Dec 2020
Edited: 24 Dec 2020