Watch Application System in Python

Currently in its infancy wasp-os provides nothing more than a simple digital clock application for PineTime together with access to the MicroPython REPL for interactive testing and tweaking. However it keeps time well and has enough power saving functions implemented that it can survive for well over 24 hours between charges so even at this early stage it is functional as a wearable timepiece.

WASP includes a robust bootloader based on the Adafruit NRF52 Bootloader. It has been extended to make it robust for development on form-factor devices without a reset button, power switch, SWD debugger or UART. This allows us to confidently develop on sealed devices relying only on BLE for updates.

Video

Building from a git clone

pip3 install --user click serial pyserial
make submodules
make softdevice
make -j `nproc` BOARD=pinetime all

Note: You will need a toolchain for the Arm Cortex-M4. wasp-os is developed and tested using the GNU-RM toolchain (9-2019-q4) from Arm.

Note #2: There are known problems with toolchains older than gcc-7.3 due to problems with link-time-optimization (which is enabled by default)

Installing

Note: If you have a new PineTime then it will have been delivered with flash protection enabled. You must disable the flash protection before trying to program it.

• Use an SWD programmer to install bootloader.hex to the PineTime. This file is an Intel HEX file containing both the bootloader and the Nordic SoftDevice. Be careful to disconnect cleanly from the debug software since just pulling out the SWD cable will mean the nRF52 will still believe it is being debugged.
• Copy micropython.zip to your Android device and download nRF Connect for Android if you do not already have it.
• In nRF Connect, choose settings and reduce the DFU packet count from 10 to 4.
• Connect to PineDFU using nRFConnect, click the DFU button and send micropython.zip to the device.

At the end of this process your watch will show the time (12:00) and a battery meter. When the watch goes into power saving mode you can use the side button to wake it again.

At this point you will also be able to use the Nordic UART Service to access the MicroPython REPL, although currently you must send ^C to interrupt the program that updates the watch display.

Just for fun try:

^C
import demo
demo.run()
# After watching the demo for a bit...
^C
wasp.app.draw(watch)
wasp.run()

To set the time and restart the main application:

^C
watch.rtc.set_time((hh, mm, ss))
wasp.run()

As mentioned above there are many drivers and features still to be developed, see the TODO list for current status.