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pyb – Functions related to the board.

Functions related to the board.

The pyb module contains specific functions related to the board.

Attributes

hid_keyboard	A tuple of (subclass, protocol, max packet length, polling interval, report
hid_mouse	A tuple of (subclass, protocol, max packet length, polling interval, report

Functions

bootloader(→ None)	Activate the bootloader without BOOT* pins.
delay(→ None)	Delay for the given number of milliseconds.
disable_irq(→ _typeshed.Incomplete)	Disable interrupt requests.
elapsed_micros(→ int)	Returns the number of microseconds which have elapsed since start.
elapsed_millis(→ int)	Returns the number of milliseconds which have elapsed since start.
enable_irq(→ None)	Enable interrupt requests.
fault_debug(→ None)	Enable or disable hard-fault debugging. A hard-fault is when there is a fatal
freq(→ Tuple)	If given no arguments, returns a tuple of clock frequencies:
hard_reset(→ NoReturn)	Resets the pyboard in a manner similar to pushing the external RESET
have_cdc(→ bool)	Return True if USB is connected as a serial device, False otherwise.
hid(→ _typeshed.Incomplete)	Takes a 4-tuple (or list) and sends it to the USB host (the PC) to
info(→ None)	Print out lots of information about the board.
main(→ None)	Set the filename of the main script to run after boot.py is finished. If
micros(→ int)	Returns the number of microseconds since the board was last reset.
millis(→ int)	Returns the number of milliseconds since the board was last reset.
mount(→ int)
repl_uart(→ UART.UART)	Get or set the UART object where the REPL is repeated on.
rng(→ int)	Return a 30-bit hardware generated random number.
standby(→ _typeshed.Incomplete)	Put the pyboard into a "deep sleep" state.
stop(→ _typeshed.Incomplete)	Put the pyboard in a "sleeping" state.
sync(→ None)	Sync all file systems.
udelay(→ None)	Delay for the given number of microseconds.
unique_id(→ str)	Returns a string of 12 bytes (96 bits), which is the unique ID of the MCU.
usb_mode([hid, high_speed])	If called with no arguments, return the current USB mode as a string.
wfi(→ None)	Wait for an internal or external interrupt.

Module Contents

pyb.bootloader() → None

Activate the bootloader without BOOT* pins.

pyb.delay(ms) → None

Delay for the given number of milliseconds.

pyb.disable_irq() → Incomplete

Disable interrupt requests. Returns the previous IRQ state: False/True for disabled/enabled IRQs respectively. This return value can be passed to enable_irq to restore the IRQ to its original state.

pyb.elapsed_micros(start) → int

Returns the number of microseconds which have elapsed since start.

This function takes care of counter wrap, and always returns a positive number. This means it can be used to measure periods up to about 17.8 minutes.

Example:

start = pyb.micros()
while pyb.elapsed_micros(start) < 1000:
    # Perform some operation
    pass

pyb.elapsed_millis(start) → int

Returns the number of milliseconds which have elapsed since start.

This function takes care of counter wrap, and always returns a positive number. This means it can be used to measure periods up to about 12.4 days.

Example:

start = pyb.millis()
while pyb.elapsed_millis(start) < 1000:
    # Perform some operation

pyb.enable_irq(state=True) → None

Enable interrupt requests. If state is True (the default value) then IRQs are enabled. If state is False then IRQs are disabled. The most common use of this function is to pass it the value returned by disable_irq to exit a critical section.

pyb.fault_debug(value) → None

Enable or disable hard-fault debugging. A hard-fault is when there is a fatal error in the underlying system, like an invalid memory access.

If the value argument is False then the board will automatically reset if there is a hard fault.

If value is True then, when the board has a hard fault, it will print the registers and the stack trace, and then cycle the LEDs indefinitely.

The default value is disabled, i.e. to automatically reset.

pyb.freq(sysclk=0, hclk=0, pclk1=0, pclk2=0) → Tuple

If given no arguments, returns a tuple of clock frequencies: (sysclk, hclk, pclk1, pclk2). These correspond to:

• sysclk: frequency of the CPU

• hclk: frequency of the AHB bus, core memory and DMA

• pclk1: frequency of the APB1 bus

• pclk2: frequency of the APB2 bus

If given any arguments then the function sets the frequency of the CPU, and the buses if additional arguments are given. Frequencies are given in Hz. Eg freq(120000000) sets sysclk (the CPU frequency) to 120MHz. Note that not all values are supported and the largest supported frequency not greater than the given value will be selected.

Supported sysclk frequencies are (in MHz): 8, 16, 24, 30, 32, 36, 40, 42, 48, 54, 56, 60, 64, 72, 84, 96, 108, 120, 144, 168.

The maximum frequency of hclk is 168MHz, of pclk1 is 42MHz, and of pclk2 is 84MHz. Be sure not to set frequencies above these values.

The hclk, pclk1 and pclk2 frequencies are derived from the sysclk frequency using a prescaler (divider). Supported prescalers for hclk are: 1, 2, 4, 8, 16, 64, 128, 256, 512. Supported prescalers for pclk1 and pclk2 are: 1, 2, 4, 8. A prescaler will be chosen to best match the requested frequency.

A sysclk frequency of 8MHz uses the HSE (external crystal) directly and 16MHz uses the HSI (internal oscillator) directly. The higher frequencies use the HSE to drive the PLL (phase locked loop), and then use the output of the PLL.

Note that if you change the frequency while the USB is enabled then the USB may become unreliable. It is best to change the frequency in boot.py, before the USB peripheral is started. Also note that sysclk frequencies below 36MHz do not allow the USB to function correctly.

pyb.hard_reset() → NoReturn

Resets the pyboard in a manner similar to pushing the external RESET button.

pyb.have_cdc() → bool

Return True if USB is connected as a serial device, False otherwise.

Note

This function is deprecated. Use pyb.USB_VCP().isconnected() instead.

pyb.hid(hid_tuple: Tuple) → Incomplete

Takes a 4-tuple (or list) and sends it to the USB host (the PC) to signal a HID mouse-motion event.

Note

This function is deprecated. Use pyb.USB_HID.send() instead.

pyb.info(dump_alloc_table: Any | None = None) → None

Print out lots of information about the board.

pyb.main(filename) → None

Set the filename of the main script to run after boot.py is finished. If this function is not called then the default file main.py will be executed.

It only makes sense to call this function from within boot.py.

pyb.micros() → int

Returns the number of microseconds since the board was last reset.

The result is always a MicroPython smallint (31-bit signed number), so after 2^30 microseconds (about 17.8 minutes) this will start to return negative numbers.

Note that if pyb.stop() is issued the hardware counter supporting this function will pause for the duration of the “sleeping” state. This will affect the outcome of pyb.elapsed_micros().

pyb.millis() → int

Returns the number of milliseconds since the board was last reset.

The result is always a MicroPython smallint (31-bit signed number), so after 2^30 milliseconds (about 12.4 days) this will start to return negative numbers.

Note that if pyb.stop() is issued the hardware counter supporting this function will pause for the duration of the “sleeping” state. This will affect the outcome of pyb.elapsed_millis().

pyb.mount(device, mountpoint, *, readonly=False, mkfs=False) → int

Note

This function is deprecated. Mounting and unmounting devices should be performed by vfs.mount() and vfs.umount() instead.

Mount a block device and make it available as part of the filesystem. device must be an object that provides the block protocol. (The following is also deprecated. See vfs.AbstractBlockDev for the correct way to create a block device.)

• readblocks(self, blocknum, buf)

• writeblocks(self, blocknum, buf) (optional)

• count(self)

• sync(self) (optional)

readblocks and writeblocks should copy data between buf and the block device, starting from block number blocknum on the device. buf will be a bytearray with length a multiple of 512. If writeblocks is not defined then the device is mounted read-only. The return value of these two functions is ignored.

count should return the number of blocks available on the device. sync, if implemented, should sync the data on the device.

The parameter mountpoint is the location in the root of the filesystem to mount the device. It must begin with a forward-slash.

If readonly is True, then the device is mounted read-only, otherwise it is mounted read-write.

If mkfs is True, then a new filesystem is created if one does not already exist.

pyb.repl_uart(uart) → UART

Get or set the UART object where the REPL is repeated on.

pyb.rng() → int

Return a 30-bit hardware generated random number.

pyb.standby() → Incomplete

Put the pyboard into a “deep sleep” state.

This reduces power consumption to less than 50 uA. To wake from this sleep state requires a real-time-clock event, or an external interrupt on X1 (PA0=WKUP) or X18 (PC13=TAMP1). Upon waking the system undergoes a hard reset.

See rtc.wakeup() to configure a real-time-clock wakeup event.

pyb.stop() → Incomplete

Put the pyboard in a “sleeping” state.

This reduces power consumption to less than 500 uA. To wake from this sleep state requires an external interrupt or a real-time-clock event. Upon waking execution continues where it left off.

See rtc.wakeup() to configure a real-time-clock wakeup event.

pyb.sync() → None

Sync all file systems.

pyb.udelay(us) → None

Delay for the given number of microseconds.

pyb.unique_id() → str

Returns a string of 12 bytes (96 bits), which is the unique ID of the MCU.

pyb.usb_mode(modestr: Any | None = None, port=-1, vid=61525, pid=-1, msc=(), hid=hid_mouse, high_speed=False) → str

If called with no arguments, return the current USB mode as a string.

If called with modestr provided, attempts to configure the USB mode. The following values of modestr are understood:

• None: disables USB

• 'VCP': enable with VCP (Virtual COM Port) interface

• 'MSC': enable with MSC (mass storage device class) interface

• 'VCP+MSC': enable with VCP and MSC

• 'VCP+HID': enable with VCP and HID (human interface device)

• 'VCP+MSC+HID': enabled with VCP, MSC and HID (only available on PYBD boards)

For backwards compatibility, 'CDC' is understood to mean 'VCP' (and similarly for 'CDC+MSC' and 'CDC+HID').

The port parameter should be an integer (0, 1, …) and selects which USB port to use if the board supports multiple ports. A value of -1 uses the default or automatically selected port.

The vid and pid parameters allow you to specify the VID (vendor id) and PID (product id). A pid value of -1 will select a PID based on the value of modestr.

If enabling MSC mode, the msc parameter can be used to specify a list of SCSI LUNs to expose on the mass storage interface. For example msc=(pyb.Flash(), pyb.SDCard()).

If enabling HID mode, you may also specify the HID details by passing the hid keyword parameter. It takes a tuple of (subclass, protocol, max packet length, polling interval, report descriptor). By default it will set appropriate values for a USB mouse. There is also a pyb.hid_keyboard constant, which is an appropriate tuple for a USB keyboard.

The high_speed parameter, when set to True, enables USB HS mode if it is supported by the hardware.

pyb.wfi() → None

Wait for an internal or external interrupt.

This executes a wfi instruction which reduces power consumption of the MCU until any interrupt occurs (be it internal or external), at which point execution continues. Note that the system-tick interrupt occurs once every millisecond (1000Hz) so this function will block for at most 1ms.

pyb.hid_keyboard: int

A tuple of (subclass, protocol, max packet length, polling interval, report descriptor) to set appropriate values for a USB mouse or keyboard.

pyb.hid_mouse: int

A tuple of (subclass, protocol, max packet length, polling interval, report descriptor) to set appropriate values for a USB mouse or keyboard.

Submodules

• pyb.ADC
• pyb.Accel
• pyb.CAN
• pyb.DAC
• pyb.ExtInt
• pyb.Flash
• pyb.I2C
• pyb.LCD
• pyb.LED
• pyb.Pin
• pyb.RTC
• pyb.SPI
• pyb.Servo
• pyb.Switch
• pyb.Timer
• pyb.UART
• pyb.USB_HID
• pyb.USB_VCP