.. the documentation doesn't make this clear, but in practice it works
to write both of the DATABUF registers at the same time. This should
also reduce the amount of wear and tear DMA puts on the system, as the
number of transfers is cut in half. (the number of bytes transferred
remains the same, though)
In principle, this could cover all stereo cases if audio_dma_convert_signed
also learned to 16-bit extend and swap values. However, this is the
case that matters for stereo mp3 playback on PyGamer.
Testing performed: Listened to some tracks with good stereo separation.
This adapts the "inline assembler" code from the UF2 bootloader, which
in turn is said to be adapted from the arduino neopixel library.
This requires the cache remain ON when using M0, and be turned OFF on M4
(determined by trial and error)
Testing performed on a Metro M4:
* measured timings using o'scope and found all values within
datasheet tolerance.
* Drove a string of 96 neopixels without visible glitches
* on-board neopixel worked
Testing performed on a Circuit Playground Express (M0):
* Color wheel code works on built-in neopixels
* Color wheel code works on 96 neopixel strip
As a bonus, this may have freed up a bit of flash on M0 targets. (2988 ->
3068 bytes free on Trinket M0)
Closes: #2297
This code is shared by most parts, except where not all the #ifdefs
inside the tick function were present in all ports. This mostly would
have broken gamepad tick support on non-samd ports.
The "ms32" and "ms64" variants of the tick functions are introduced
because there is no 64-bit atomic read. Disabling interrupts avoids
a low probability bug where milliseconds could be off by ~49.5 days
once every ~49.5 days (2^32 ms).
Avoiding disabling interrupts when only the low 32 bits are needed is a minor
optimization.
Testing performed: on metro m4 express, USB still works and
time.monotonic_ns() still counts up
Fixes#2086
When the frequency of a `PWMOut` is change it re-sets the PWM's duty cycle as
well, since the registers have to be re-calculated based on the new frequency.
Unfortunately, `common_hal_pulseio_pwmout_get_duty_cycle`
will return a value very close to, but not exactly, the value passed to `common_hal_pulseio_pwmout_set_duty_cycle`. If the frequency is modified
without the calling code also re-setting the duty cycle then the duty cycle
will decay over time. This fixes that problem by tracking the unadjusted duty
cycle and re-setting the duty cycle to that value when the frequency is changed.
Make changes in asf4_conf even though I think in these cases the
"peripherals" submodule is running the show.
Arduino clocks the DAC at 12MHz but uses the CCTRL setting for
clocking < 1.2MHz (100kSPS).
A fresh clock (6) is allocated for the new 12MHz clock. This matches
the Arduino value, though not the GCLK index.
Modify other settings to more closely resemble Arduino.
In AudioOut, actually clock the waveform data from the timer we set up
for this purpose.
This gives good waveforms when setting AnalogOut full-scale in a loop,
but the rise/fall of waveforms that come from AudioOut are still erratic.
Weirdly, if AudioOut limits its range even slightly (e.g., to 1000..64000)
then the erratic
Note that this will require https://github.com/adafruit/samd-peripherals/pull/26
to be accepted for the submodule update here to work.
Previously, we depended on allocated channels to always be
"dma_channel_enabled". However, (A) sometimes, many operations
would take place between find_free_audio_dma_channel and
audio_dma_enable_channel, and (B) some debugging I did led me to believe
that "dma_channel_enabled" would become false when the hardware ended
a scheduled DMA transaction, but while a CP object would still think it
owned the DMA channel.
((B) is not documented in the datasheet and I am not 100% convinced that
my debugging session was not simply missing where we were disabling the
channel, but in either case, it shows a need to directly track allocated
separately from enabled)
Therefore,
* Add audio_dma_{allocate,free}_channel.
* audio_dma_free_channel implies audio_dma_disable_channel
* track via a new array audio_dma_allocated[]
* clear all allocated flags on soft-reboot
* Convert find_free_audio_dma_channel to audio_dma_allocate_channel
* use audio_dma_allocated[] instead of dma_channel_enabled() to check
availability
* remove find_free_audio_dma_channel
* For each one, find a matching audio_dma_disable_channel to convert
to audio_dma_free_channel
Closes: #2058
.. otherwise, a sequence like
>>> a = audioio.AudioOut(board.A0)
>>> a.play(sample, loop=True)
>>> a.deinit()
would potentially leave related DMA channel(s) active.
When nrf pwm audio is introduced, it will be called `audiopwmio`. To
enable code sharing with the existing (dac-based) `audioio`, factor
the sample and mixer types to `audiocore`.
INCOMPATIBLE CHANGE: Now, `Mixer`, `RawSample` and `WaveFile` must
be imported from `audiocore`, not `audioio`.
This also improves Palette so it stores the original RGB888 colors.
Lastly, it adds I2CDisplay as a display bus to talk over I2C. Particularly
useful for the SSD1306.
Fixes#1828. Fixes#1956
If one of the default pins was already in use it would crash.
The internal API has been refined to allow us to get the value
without causing an init of the singleton.
Fixes#1753
This should allow you to use SWD pins unless a debugger is attached.
You may have trouble connecting to SWD when CircuitPython has already
begun using them.
Fixes#1633
The backtrace cannot be given because it relies on the validity
of the qstr data structures on the heap which may have been
corrupted.
In fact, it still can crash hard when the bytecode itself is
overwritten. To fix, we'd need a way to skip gathering the
backtrace completely.
This also increases the default stack size on M4s so it can
accomodate the stack needed by ASF4s nvm API.
This started while adding USB MIDI support (and descriptor support is
in this change.) When seeing that I'd have to implement the MIDI class
logic twice, once for atmel-samd and once for nrf, I decided to refactor
the USB stack so its shared across ports. This has led to a number of
changes that remove items from the ports folder and move them into
supervisor.
Furthermore, we had external SPI flash support for nrf pending so I
factored out the connection between the usb stack and the flash API as
well. This PR also includes the QSPI support for nRF.
This reduces the popping sound on initial playback of an audio
sample.
The M4 DAC has a pop on startup that cannot be prevented. It also
does not allow readback so current values of the DAC are ignored.
Fixes#1090
