The PIO state machines on the RP2040 have 4 word deep TX and RX FIFOs. If
you only need one direction, you can "merge" them into either a single 8
word deep TX or RX FIFO.
We simply add constants to the PIO object, and set the appropriate bits in
`shiftctrl`.
Resolves#6854.
Signed-off-by: Tim Radvan <tim@tjvr.org>
This change allows to build firmware for different rp2-based boards,
following how it is done in other ports like stm32 and esp32. So far only
the original Pico and Adafruit Feather RP2040 are added. Board names
should match (sans case) those in pico-sdk/src/boards/include/boards/.
Usage: Pico firmware can be build either using make as previously (it is
the default board) or by `make BOARD=PICO`. Feather is built by `make
BOARD=ADAFRUIT_FEATHER_RP2040`. Only the board name and flash drive size
is set, pin definition is taken from the appropriate pico-sdk board
definition. Firmware is saved in the directory build-BOARD_NAME.
Instantiation and init now support the rxbuf and txbuf keywords for setting
the buffer size. The default size is 256 bytes. The minimum and maximum
sizes are 32 and 32766 respectively.
uart.write() still includes checks for timeout, even if it is very unlikely
to happen due to a) lack of flow control support and b) the minimal timeout
values being longer than the time it needs to send a byte.
StateMachine.restart: Restarts the state machine
StateMachine.rx_fifo: Return the number of RX FIFO items, 0 if empty
StateMachine.tx_fifo: Return the number of TX FIFO items, 0 if empty
restart() seems to be the most useful one, as it resets the state machine
to the initial state without the need to re-initialise/re-create. It also
makes PIO code easier, because then stalling as an error state can be
unlocked.
rx_fifo() is also useful, for MP code to check for data and timeout if no
data arrived. Complex logic is easier handled in Python code than in PIO
code.
tx_fifo() can be useful to check states where data is not processed, and is
mostly for symmetry.
The implementation samples rosc.randombits at a frequency lower than the
oscillator frequency. This gives better random values. In addition, for
an 8-bit value 8 samples are taken and fed through a 8-bit CRC,
distributing the sampling over the byte. The resulting sampling rate is
about 120k/sec.
The RNG does not include testing of error conditions, like the ROSC being
in sync with the sampling or completely failing. Making the interim value
static causes it to perform a little bit better in short sync or drop-out
situations.
The output of uos.urandom() performs well with the NIST800-22 test suite.
In my trial it passed all tests of the sts 2.1.2 test suite. I also ran a
test of the random data with the Common Criteria test suite AIS 31, and it
passed all tests too.
Some forum users noticed that `sm.exec()` took longer the more was present
on the flash filesystem connected to the RP2040. They traced this back to
the `array` import inside `asm_pio()`, which is causing MicroPython to scan
the filesystem.
uarray is a built-in module, so importing it shouldn't require scanning the
filesystem.
We avoid moving the import to the top-level in order to keep the namespace
clean; we don't want to accidentally expose `rp2.array`.
This is a workaround for errata RP2040-E5, and is needed to make USB more
reliable on certain USB ports.
Signed-off-by: Damien George <damien@micropython.org>
This USB feature is currently not supported. With this flag enabled (and
the feature not implemented) the USB serial will stop working if there is a
delay of more than about 2 seconds between messages, which can occur with
USB autosuspend enabled.
Fixes issue #6866.
The parts that are generic are added to py/ so they can be used by other
ports that use CMake.
py/usermod.cmake:
* Creates a usermod target to hang user C/CXX modules from.
* Gathers sources from user C/CXX modules and libs for QSTR scan.
ports/rp2/CMakeLists.txt:
* Includes py/usermod.cmake.
* Links the resulting usermod library to the MicroPython target.
py/mkrules.cmake:
Add cxxflags to qstr.i.last custom command for CXX modules:
* MICROPY_CPP_FLAGS so CXX modules will find includes.
* -DNO_QSTR to fix fatal error missing "genhdr/qstrdefs.generated.h".
Usage:
The rp2 port can be linked against user C modules by running:
make USER_C_MODULES=/path/to/module/micropython.cmake
CMake will print a list of included modules.
Co-authored-by: Graham Sanderson <graham.sanderson@raspberrypi.org>
Co-authored-by: Michael O'Cleirigh <michael.ocleirigh@rivulet.ca>
Signed-off-by: Phil Howard <phil@pimoroni.com>
When UART is used for REPL and the MCU frequency is changed, the UART
has to be re-initialised. Besides that the UART may have to be recreated
after a frequency change, but with USB REPL this is not a problem.
Thanks to @HermannSW for spotting and providing the change.
Using the standard machine.freq().
The safe ranges tested were 10 and 12-270MHz, at which USB REPL still
worked. Requested settings can be checked with the script:
pico-sdk/src/rp2_common/hardware_clocks/scripts/vcocalc.py. At frequencies
like 300MHz the script still signaled OK, but USB did not work any more.
sm.get(buf) was waiting for one item more than the length of the supplied
buffer. Even if this item was not stored, sm_get would block trying to get
an item from the RX fifo.
As part of the fix, the edge case for a zero length buffer was moved up to
the section where the function arguments are handled. In case of a zero
length buffer, sm.get() now returns immediately that buffer.
The bitmasks supplied for initialization of out/set/sideset were only 8 bit
instead of 32. This resulted in an error, that not more than 8 consecutive
pins would get initialized.
Fixes issue #6933.
These ports already have uzlib enabled so this additional ubinascii.crc32
function only costs about 90 bytes of flash.
Signed-off-by: Damien George <damien@micropython.org>
So that all MicroPython ports that use tinyusb use the same version. Also
requires fewer submodule checkouts when building rp2 along with other ports
that use tinyusb.
Signed-off-by: Damien George <damien@micropython.org>
In particular the firmware can now be built in a build directory that lives
outside the source tree, and the py/modarray.c file will still be found.
See issue #6837.
Signed-off-by: Damien George <damien@micropython.org>
Otherwise it resets the ADC peripheral each time a new ADC object is
constructed, which can reset other state that has already been set up.
See issue #6833.
Signed-off-by: Damien George <damien@micropython.org>
PIO state machines can make a conditional jump on the state of a pin: the
`JMP PIN` command. This requires the pin to be configured with
`sm_config_set_jmp_pin`, but until now we didn't have a way of doing that
in MicroPython.
This commit adds a new `jmp_pin=None` argument to `StateMachine`. If it is
not `None` then we try to interpret it as a Pin, and pass its value to
`sm_config_set_jmp_pin`.
Signed-off-by: Tim Radvan <tim@tjvr.org>
This commit adds a new port "rp2" which targets the new Raspberry Pi RP2040
microcontroller.
The build system uses pure cmake (with a small Makefile wrapper for
convenience). The USB driver is TinyUSB, and there is a machine module
with most of the standard classes implemented. Some examples are provided
in the examples/rp2/ directory.
Work done in collaboration with Graham Sanderson.
Signed-off-by: Damien George <damien@micropython.org>
