The boot counter is a uint8_t single-byte counter stored in the first NVM byte position (`micrcontroller.nvm[0]`). The counter increments by 1 each time the board boots, regardless if it's a hard or soft reset.
Enable the boot counter by adding `#define CIRCUITPY_BOOT_COUNTER 1` to your board's mpconfigboard.h file. Note that an error will be thrown during the build if `CIRCUITPY_INTERNAL_NVM_SIZE` is not also set within mpconfigboard.h.
* Reduce the number of supported HID reports of IDs per descriptor.
This saves ~200 bytes in the default HID objects.
* (Not enabled) Compute QSTR attrs on init. This trades 1k RAM for
flash. Flash is the default (1).
The frequency divisor is limited to 255, which gives 48MHz/2/255 ~= 94.1kHz as
the lowest speed.
Without this change, values below this cut-off gave higher frequencies instead,
which didn't appear to have any relation to the frequency value requested.
Closes: #4883
There is a race between when we run background tasks and when we
sleep. If an interrupt happens between the two, then we may delay
executing the background task. On some ports we checked this for
TinyUSB already. On iMX RT, we didn't which caused USB issues.
This PR makes it more generic for all background tasks including
USB.
Fixes#5086 and maybe others.
This leaves much more space on SAMD21 builds that aren't "full builds".
These are new APIs that we don't need to add to old boards.
Also, tweak two Arduino boards to save space on them.
The EVSYS is used to generate an interrupt from the event. This
simplifies timing used in pulseio that conflicted with the
auto-reload countdown.
Fixes#3890
RP2040 and SAMD51:
- Detect when DMA has finished, and stop DMA audio explicitly.
- Do not accidentally reuse `first_buffer` supplied by WaveFile or RawSample. Always realloc `first_buffer` and `second_buffer`
RP2040:
- When audio playing is stopped, write a final zero to the output register. This prevents residual PWM tones.
- Handle buffer size for 8-bit samples properly for 16-bit output.
- Fail on some edge cases (which may not be possible at the moment).
