The machine module contains specific functions related to the micro:bit hardware. Most functions in this module allow to achieve direct and unrestricted access to and control of hardware blocks on a system (like CPU, timers, buses, etc.). Used incorrectly, this can lead to malfunction, lockups, crashes of your board, and in extreme cases, hardware damage.



Returns a byte string with a unique identifier of a board. It will vary from one board instance to another.


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


Returns CPU frequency in hertz.


Disable interrupt requests. Returns the previous IRQ state which should be considered an opaque value. This return value should be passed to the machine.enable_irq() function to restore interrupts to their original state, before machine.disable_irq() was called.


Re-enable interrupt requests. The state parameter should be the value that was returned from the most recent call to the machine.disable_irq() function.

machine.time_pulse_us(pin, pulse_level, timeout_us=1000000)

Time a pulse on the given pin, and return the duration of the pulse in microseconds. The pulse_level argument should be 0 to time a low pulse or 1 to time a high pulse.

If the current input value of the pin is different to pulse_level, the function first (*) waits until the pin input becomes equal to pulse_level, then (**) times the duration that the pin is equal to pulse_level. If the pin is already equal to pulse_level then timing starts straight away.

The function will return -2 if there was timeout waiting for condition marked (*) above, and -1 if there was timeout during the main measurement, marked (**) above. The timeout is the same for both cases and given by timeout_us (which is in microseconds).

Reading Memory

The machine module allows you to read from the device’s memory, getting 1 byte (8 bits; mem8), 2 byte (16 bits; mem16), or 4 byte (32 bits; mem32) words from physical addresses. For example: mem8[0x00] reads 1 byte on physical address 0x00. This has a number of uses, for example if you’d like to read data from the nRF51 registers.