TTGO-esp32-micropython-watch

Playground ESP32 based micropython watch based utilising the TTGO 2020 watches hardware

Setup

To setup the install for the environment you'll need to first install the micropython firmware included in this repo to the board. There's a good doc here which oultlines how to install the ESP32 flashing tool we'll use during development. Once it's installed we can flash the firmware and get the environment running.

Firstly we'll wipe the inital flash envrionment to clear anything that might be on the watch

NOTE these docs assume a linux environment if your developing on mac/windows there's other readme's out there you can follow.

sudo esptool.py --chip esp32 --port /dev/ttyUSB0 erase_flash

This should take about 30 seconds and dump return a sucess status on completion. Next we need to flash the base firmware, you can do this by running

esptool.py --chip esp32 --port /dev/ttyUSB0 write_flash -z 0x1000 ~/<relative-directory>/TTGO-micropython-watch/firmware/TTGO_watch_2020_esp32.bin

This takes about 2 minutes and on completion have the full micropython environment installed and ready to connect too.

We can test this by connecting to the REPL by going

picocom /dev/ttyUSB0 -b115200

Depending on how your permissions are setup you may need to change the permission setting to make it readable

sudo chmod 777 /dev/ttyUSB0

here you should be greeted with the terminal.

If you want to do a simple hello world of the hardware you can run

from time import sleep
from machine import Pin

vibrator = Pin(4, Pin.OUT)
vibrator.on()
sleep(1)
vibrator.off()

Which will cycle the vibrator motor on the watch on or off.

Flashing the app

To flash the development code I personally use IDEA's pycharm micropython plugin, as it takes care of ignoring the non project python files and allows you to whitelist/blacklist files/folders that are included for upload on the watch.

If your wanting to stick to the command line approach I'd suggest using ampy to do it which would have been installed during the esptool.py setup, there's a good overview of commands here

Project structure

• main.py Entrypoint for script, sets up drivers and any pre app code that needs to be initialized
• system.py Contains shared app state settings class, and connectors for network
• config.py Ommited from the app contains private settings variables we want included in the app but don't want uploaded to git
• apps Contains the watch apps, also contains a shared base class new apps can be based off of.
• firmware packaged Micropython firmware from RussHuges containing a few prebuild libraries we want to use.
• libs vendor code or snippets taken from other libraries

Config with config.py

TODO this will be changed but serves it's purpose for now. On build we'll need to add a config.py file containing our private wifi key plus any other configuration.

At the moment this project only expects a single variable

WIFI_CONNECTIONS = [('WIFI-AP-name', 'password')]

You can add multiple AP configs to this and the app will try to connect to one of them on first boot, this will be changed in the future.

Thanks

• https://github.com/russhughes/st7789_mpy (For his excellent bundling of the micropython firmware and extension of the st7789 display library)