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).
Passing in a PWMOut still works but is deprecated. It will be
removed in CircuitPython 8.0.0
This also switches STM32 timer indices and channel indices to
0-based in our pin data rather than `- 1` everywhere. The latter is
more bug prone.
Most of the way for #3264
Tested on Metro M0, Metro M4, Feather S2, Feather nRF52840, Feather
STM32F4 and Arduino RP2040.
After the script stops with the exception thrown the final gc_sweep
will call any finalizers and they usually call deinit. deinit on
invalid objects can wreak havoc by changing random memory or
(hopefully) crashing. This fixes ensures the object is deinited
until initialization succeeds and the object is valid.
Do the same fix for I2C and SPI too.
Fixes#4700 and fixes#5005
