I2C & SPI pins are not released when modules are initialised with different pins

[microbit-carlos]

With the update from #112 and #111 we can change the I2C and SPI pins to other pins than 19 and 20. However, the pin modes are not updated.

Using a build from the latest commit in main:
https://github.com/microbit-foundation/micropython-microbit-v2/actions/runs/7565598370

>>> pin19.get_mode()
'i2c'
>>> pin0.get_mode()
'unused'
>>> i2c.init(sda=pin0, scl=pin1)
>>> i2c.scan()
[]
>>> pin0.get_mode()
'unused'
>>> pin0.write_digital(1)
>>> pin19.get_mode()
'i2c'
>>> pin19.write_digital(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: Pin 19 in i2c mode

>>> pin13.get_mode()
'unused'
>>> spi.init(sclk=pin13, mosi=pin15, miso=pin14)
>>> pin13.get_mode()
'spi'
>>> spi.init(sclk=pin8, mosi=pin12, miso=pin16)
>>> pin13.get_mode()
'spi'
>>> pin8.get_mode()
'spi'
>>> pin8.write_digital(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: function takes 2 positional arguments but 1 were given
>>> pin13.write_digital(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: Pin 8 in spi mode
>>> 

[microbit-carlos]

@dpgeorge is it possible that this issue is caused by this? Or is it something else?

• CODAL peripheral destructors should call free_alloc_peri() lancaster-university/codal-microbit-v2#219

[dpgeorge]

The problem here is MicroPython specific, it's because previous I2C and SPI pins are not being released, and new ones not being acquired.

[dpgeorge]

Fixed by af721c7