I want to make develop for the SensorWatch easier, so I'm trying to setup and document how to setup an SWD debugger for a watch you could see the LCD and use the buttons on. It will have a bunch of wires sticking out, so it's not going to be possible to wear, but it should allow for faster development and verification. I started this quite a while ago when I solder some [36 AWG wire](https://www.adafruit.com/product/4733) to the 5 debug pads on the sensor watch and connected them to an [Cortex Debug 10-pin](https://developer.arm.com/documentation/101416/0100/Hardware-Description/Target-Interfaces/Cortex-Debug--10-pin-) connector. It worked with my J-Link mini edu, but that debugger doesn't have power so I had to leave a coin cell inside the watch, which eventually died and I didn't feel like replacing. I got bored for a while and I wasn't motivated enough to drop $100 on a black magic probe, or a fancier J-Link. Cut to a week or so ago when I realized that I can put the [pi debug-probe](https://github.com/raspberrypi/debugprobe) firmware on a plain pico which has both 5V and 3.3V! And it's pretty dirt cheap, and I have one sitting around. The [PDF documentation](https://cdn.tahnok.ca/u/getting-started-with-pico.pdf)(specficially appendix A) was really good and includes a wiring diagram which is GP2 -> SWCLK GP3 ->SWDIO After wiring things up and running ``` sudo openocd -f interface/cmsis-dap.cfg -c "adapter speed 5000" -f target/atsaml1x.cfg -s tcl ``` (I'm sure the sudo could be avoided with udev) it worked! I can connect and reset the watch, but it's not all perfect yet. At the moment, the watch is stuck in bootloader mode, where the red LED flashes repeatedly. Nothing is displayed on the LCD either.