suspect-devices/circuitpython/ports/mimxrt10xx/common-hal, branch mainCircuitPython - a Python implementation for teaching coding with microcontrollershttps://git.suspectdevices.com/suspect-devices/circuitpython/atom?h=main2021-04-01T18:04:06+00:00mimxrt1011: pwmout: Add prescaler, fix duty_cycle=655352021-04-01T18:04:06+00:00Jeff Eplerjepler@gmail.com2021-04-01T18:04:06+00:00urn:sha1:89fc0298ce6d7ee64246ce263223ce26883125a4mimxrt1011: pwmio: Enable basic PWMOut functionality2021-04-01T15:06:59+00:00Jeff Eplerjepler@gmail.com2021-04-01T14:37:39+00:00urn:sha1:489163b74edf9d6f40b3d9e6ee0154d2f1ddce79
After this change, the following program works for me on the MIMXRT1010-EVK:
```python
import pwmio
import board
p = pwmio.PWMOut(board.D13, frequency=1_000_000, variable_frequency=True)
p.duty_cycle = 32868
while True:
pass
```
Querying and varying the duty_cycle and frequency work as well.
The lowest frequency obtainable is about 2kHz; there is an additional
divider which would allow lower PWM frequencies (I think 1kHz is important
for servos?)
Something odd happens with very low duty cycles, such as
```python
>>> p.frequency = 2000
>>> p.duty_cycle = 2
```
instead of a symmetrical waveform, it's asymmetrical. With `duty_cycle=4`,
the effect disappears. The reason for this is probably hidden in the
datasheet, but could affect servos or other things that count pulse
widths.
mimxrt10xx: Fix bogus assertion.2021-03-31T14:21:08+00:00Jeff Eplerjepler@gmail.com2021-03-31T14:21:06+00:00urn:sha1:cb29ad0846c8da2d25c157a4b1d3cf9affd89e44
.. as noted by @d-c-d
mimxrt1011: UART: Add additional error checking2021-03-30T15:17:48+00:00Jeff Eplerjepler@gmail.com2021-03-30T15:11:12+00:00urn:sha1:71eee45a3779559686c5d07d9864aad679121ab6
.. and make the 'invalid pin' messages standard.
Closes #4502
Parenthesize double-division for clarity2021-03-26T16:01:22+00:00Jeff Eplerjepler@unpythonic.net2021-03-26T16:01:22+00:00urn:sha1:2bc61b458070f9e1e5a49442a72c43c0d9ea721fmimxrt10xx: Use the proper "betweenTransferDelay" (et al) values2021-03-26T15:54:13+00:00Jeff Eplerjepler@unpythonic.net2021-03-26T15:54:13+00:00urn:sha1:231cb1ffd954dad45223bcc6fd22f344089536f1
Set the betweenTransferDelay to the SCK low-time, to avoid long pauses
between bytes (transfers) while preventing the last SCK cycle in a byte
from being a runt pulse.
Compared to an earlier revision of this change, which just set the delays
all to zero, this doesn't break using an AirLift, which was sensitive
to the runt pulses (the simple loopback-wire test didn't detect the problem)
mimxrt10xx: Factor out "transfer_common"2021-03-26T15:04:35+00:00Jeff Eplerjepler@unpythonic.net2021-03-25T14:03:42+00:00urn:sha1:1d48054aeaa2762a752462a058a27afb1daac860
.. and set the "MasterPcsContinuous" flag, which removes some of the
gap between bytes of a single SPI transaction
mimxrt10xx: busio: cap SPI baudrate at 30MHz per datasheet2021-03-26T15:01:53+00:00Jeff Eplerjepler@unpythonic.net2021-03-25T18:37:37+00:00urn:sha1:9e110f120a323eff9989463771d8ea8ece6e8906mimxrt: SPI: Set the TCR value returned by MasterBaudSetRate2021-03-24T18:33:21+00:00Jeff Eplerjepler@unpythonic.net2021-03-24T18:07:07+00:00urn:sha1:b440883fe55666d12f94a6d48513a1a68d218bc4
without this, the baud rate could be wrong; in my testing, it was
low by a factor of 2 when requesating baudrate=1_000_000 (1MHz).
When passing the baudrate in to LPSPI_MasterInit, the setting is made
automatically, but LPSPI_MAster_SetBaudRate just returns it via the
out-parameter tcrPrescaleValue.
mimxrt1011: Fix reset-to-bootloader2021-03-19T15:11:45+00:00Jeff Eplerjepler@gmail.com2021-03-19T15:11:24+00:00urn:sha1:06743d91ed0df5c73fe9554dc05e47a6eeec1414
The definition of DBL_TAP_REG must match tinyuf2