4. machine module

MicroPython contains a machine module with specific functions related to the microbit.

Note

Many functions achieve direct and unrestricted access to the hardware blocks on a the microbit. Used incorrectly, this can lead to malfunction of the microbit, and in extreme cases, hardware damage.

See: https://microbit-micropython.readthedocs.io/en/v2-docs/machine.html

4.1. time_pulse_us

time_pulse_us is used by distance sensors.
See an example of its use at: https://pc-microbit-extension.readthedocs.io/en/latest/bots/Maqueen/Maqueen_distance_sensors.html
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.

e.g. pulse_time = machine.time_pulse_us(pin14, 1, 1160000) measures the time for the pulse to be reflected back.

  1. 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. The function will return -2 if there was timeout waiting for this condition.

  2. It 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 -1 if there was timeout waiting for this condition.

  3. The timeout is the same for both cases and given by timeout_us in microseconds.