Konrad RieckandClaude Sonnet 5
0b7ea662fe
date_time.unit.day is a 5-bit bitfield (max 31). Incrementing 31 directly in the bitfield wrapped to 0 via truncation before the day > days_in_month bounds check ever ran, so the overflow was never caught. The result decoded as "day 0" of the current month, i.e. the last day of the previous month, silently rolling the displayed date backwards (e.g. Aug 31 -> Jul 31 -> Jun 30). Compute the incremented day in a plain uint8_t local first, compare it against the month length, and only then write the final value into the bitfield. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PSucp94GA31sshe5AjvSzQ
Second Movement
This is the successor refactor of the Movement firmware for Sensor Watch.
Getting dependencies
You will need to install the GNU Arm Embedded Toolchain to build projects for the watch. If you're using Debian or Ubuntu, it should be sufficient to apt install gcc-arm-none-eabi.
You will need to fetch the git submodules for this repository too, with git submodule update --init --recursive
Building Second Movement
You can build the default watch firmware with:
make BOARD=board_type DISPLAY=display_type
where board_type is any of:
- sensorwatch_pro
- sensorwatch_green
- sensorwatch_red (also known as Sensor Watch Lite)
- sensorwatch_blue
and display_type is any of:
- classic
- custom
Optionally you can set the watch time when building the firmware using TIMESET=minute.
TIMESET can be defined as:
year= Sets the year to the PC'sday= Sets the default time down to the day (year, month, day)minute= Sets the default time down to the minute (year, month, day, hour, minute)
If you'd like to modify which faces are built and included in the firmware, edit movement_config.h. You will get a compilation error if you enable more faces than the watch can store.
Installing firmware to the watch
To install the firmware onto your Sensor Watch board, plug the watch into your USB port and double tap the tiny Reset button on the back of the board. You should see the LED light up red and begin pulsing. (If it does not, make sure you didn’t plug the board in upside down). Once you see the WATCHBOOT drive appear on your desktop, type make install. This will convert your compiled program to a UF2 file, and copy it over to the watch.
If you want to do this step manually, copy /build/firmware.uf2 to your watch.
Emulating the firmware
You may want to test out changes in the emulator first. To do this, you'll need to install emscripten, then run:
emmake make BOARD=sensorwatch_red DISPLAY=classic
python3 -m http.server -d build-sim
Finally, visit firmware.html to see your work.