_rp2 – Functionality specific to the RP2.
Functionality specific to the RP2.
The rp2 module contains functions and classes specific to the RP2040, as
used in the Raspberry Pi Pico.
- For more information and for example code see:
Classes
Gets the singleton object for accessing the SPI flash memory. |
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Gets the PIO instance numbered id. The RP2040 has two PIO instances, |
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Get the state machine numbered id. The RP2040 has two identical PIO |
Functions
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Temporarily turns the QSPI_SS pin into an input and reads its value, |
Module Contents
- class _rp2.Flash
Gets the singleton object for accessing the SPI flash memory.
- ioctl(cmd, arg) Incomplete
These methods implement the simple and extended block protocol defined by
os.AbstractBlockDev.
- readblocks(block_num, buf, offset: int | None = 0) Incomplete
- writeblocks(block_num, buf, offset: int | None = 0) Incomplete
- class _rp2.PIO(id)
Gets the PIO instance numbered id. The RP2040 has two PIO instances, numbered 0 and 1.
Raises a
ValueErrorif any other argument is provided.- add_program(program) Incomplete
Add the program to the instruction memory of this PIO instance.
The amount of memory available for programs on each PIO instance is limited. If there isn’t enough space left in the PIO’s program memory this method will raise
OSError(ENOMEM).
- irq(handler=None, trigger=IRQ_SM0, hard=False) Incomplete
Returns the IRQ object for this PIO instance.
MicroPython only uses IRQ 0 on each PIO instance. IRQ 1 is not available.
Optionally configure it.
- remove_program(program: Any | None = None) None
Remove program from the instruction memory of this PIO instance.
If no program is provided, it removes all programs.
It is not an error to remove a program which has already been removed.
- state_machine(id, program, *args, **kwargs) Incomplete
Gets the state machine numbered id. On the RP2040, each PIO instance has four state machines, numbered 0 to 3.
Optionally initialize it with a program: see
StateMachine.init.>>> rp2.PIO(1).state_machine(3) StateMachine(7)
- class _rp2.StateMachine(id, program=None, freq=-1, *, in_base=None, out_base=None, set_base=None, jmp_pin=None, sideset_base=None, in_shiftdir=None, out_shiftdir=None, push_thresh=None, pull_thresh=None)
Get the state machine numbered id. The RP2040 has two identical PIO instances, each with 4 state machines: so there are 8 state machines in total, numbered 0 to 7.
Optionally initialize it with the given program program: see
StateMachine.init.- active(value: Any | None = None) Incomplete
Gets or sets whether the state machine is currently running.
>>> sm.active() True >>> sm.active(0) False
- exec(instr) Incomplete
Execute a single PIO instruction.
If instr is a string then uses
asm_pio_encodeto encode the instruction from the given string.>>> sm.exec("set(0, 1)")
If instr is an integer then it is treated as an already encoded PIO machine code instruction to be executed.
>>> sm.exec(rp2.asm_pio_encode("out(y, 8)", 0))
- get(buf=None, shift=0) Incomplete
Pull a word from the state machine’s RX FIFO.
If the FIFO is empty, it blocks until data arrives (i.e. the state machine pushes a word).
The value is shifted right by shift bits before returning, i.e. the return value is
word >> shift.
- init(program, freq=-1, *, in_base=None, out_base=None, set_base=None, jmp_pin=None, sideset_base=None, in_shiftdir=None, out_shiftdir=None, push_thresh=None, pull_thresh=None) None
Configure the state machine instance to run the given program.
The program is added to the instruction memory of this PIO instance. If the instruction memory already contains this program, then its offset is re-used so as to save on instruction memory.
freq is the frequency in Hz to run the state machine at. Defaults to the system clock frequency.
The clock divider is computed as
system clock frequency / freq, so there can be slight rounding errors.The minimum possible clock divider is one 65536th of the system clock: so at the default system clock frequency of 125MHz, the minimum value of freq is
1908. To run state machines at slower frequencies, you’ll need to reduce the system clock speed withmachine.freq().in_base is the first pin to use for
in()instructions.out_base is the first pin to use for
out()instructions.set_base is the first pin to use for
set()instructions.jmp_pin is the first pin to use for
jmp(pin, ...)instructions.sideset_base is the first pin to use for side-setting.
in_shiftdir is the direction the ISR will shift, either
PIO.SHIFT_LEFTorPIO.SHIFT_RIGHT.out_shiftdir is the direction the OSR will shift, either
PIO.SHIFT_LEFTorPIO.SHIFT_RIGHT.push_thresh is the threshold in bits before auto-push or conditional re-pushing is triggered.
pull_thresh is the threshold in bits before auto-pull or conditional re-pulling is triggered.
- irq(handler=None, trigger=0 | 1, hard=False) Incomplete
Returns the IRQ object for the given StateMachine.
Optionally configure it.
- put(value, shift=0) Incomplete
Push words onto the state machine’s TX FIFO.
value can be an integer, an array of type
B,HorI, or abytearray.This method will block until all words have been written to the FIFO. If the FIFO is, or becomes, full, the method will block until the state machine pulls enough words to complete the write.
Each word is first shifted left by shift bits, i.e. the state machine receives
word << shift.
- restart() Incomplete
Restarts the state machine and jumps to the beginning of the program.
This method clears the state machine’s internal state using the RP2040’s
SM_RESTARTregister. This includes:input and output shift counters
the contents of the input shift register
the delay counter
the waiting-on-IRQ state
a stalled instruction run using
StateMachine.exec()
- rx_fifo() int
Returns the number of words in the state machine’s RX FIFO. A value of 0 indicates the FIFO is empty.
Useful for checking if data is waiting to be read, before calling
StateMachine.get().
- tx_fifo() int
Returns the number of words in the state machine’s TX FIFO. A value of 0 indicates the FIFO is empty.
Useful for checking if there is space to push another word using
StateMachine.put().
- _rp2.bootsel_button() Incomplete
Temporarily turns the QSPI_SS pin into an input and reads its value, returning 1 for low and 0 for high. On a typical RP2040 board with a BOOTSEL button, a return value of 1 indicates that the button is pressed.
Since this function temporarily disables access to the external flash memory, it also temporarily disables interrupts and the other core to prevent them from trying to execute code from flash.