931c7c1c51
This 2-in-1 PR started with the goal of support the Bangle.js 2 smartwatch with *no USB*. * Adds "secure" DFU build support with a committed private key. * Adds 3-bit color support with one dummy bit for the JDI memory display * Allows nrf boards to have a board_background_task() run in RUN_BACKGROUND_TASK. This is needed because the Bangle.js 2 uses the watchdog to reset. * Renamed port_background_task() to port_background_tick() to indicate it runs on tick, not RUN_BACKGROUND_TASK. * Marks serial connected when the display terminal is inited. This means that safe mode messages show up on the display. ACep, 7-color epaper displays also pack 3 bits in 4. So, I added that support as well. * Adds 3-bit ACeP color support for 7-color e-paper displays. (Not watch related but similar due to color depth.) * Allows a refresh sequence instead of a single int command. The 7" ACeP display requires a data byte for refresh. * Adds optional delay after resetting the display. The ACeP displays need this. (Probably to load LUTs from flash.) * Adds a cleaning phase for ACeP displays before the real refresh. For both: * Add dither support to Palette. * Palette no longer converts colors when set. Instead, it caches converted colors at each index. * ColorConverter now caches the last converted color. It should make conversions faster for repeated colors (not dithering.)
SAMD21 and SAMD51
==================
This port supports many development boards that utilize SAMD21 and SAMD51 chips. See
https://circuitpython.org/downloads for all supported boards.
Building
--------
For build instructions see this guide: https://learn.adafruit.com/building-circuitpython/
Debugging
---------
For debugging instructions see this guide: https://learn.adafruit.com/debugging-the-samd21-with-gdb
Port Specific modules
---------------------
.. toctree::
../../shared-bindings/samd/index