This is the final piece of the puzzle.
Prior to this rather considerable change, Pimoroni breakouts were not de-init'ing I2C when they failed to init()
This change adds a __del__ method which cleans up the I2C instance attached to a MicroPython object.
Under the hood this calls i2c_deinit() and resets the associated pins to their default state.
This means that I2C is now cleaned up during a *soft* reset, so running a script with the wrong pins, seeing an error,
changing the pins and running it again will not result in subsequent I2C errors. Previously a hard reset was required.
To recreate on Breakout Garden run the following code:
```
from breakout_potentiometer import BreakoutPotentiometer
from pimoroni_i2c import PimoroniI2C
i2c = PimoroniI2C()
pot = BreakoutPotentiometer(i2c)
```
This will fail correctly with "Potentiometer breakout not found when initialising."
(The default pins are configured for Pico Explorer)
Now change that to the following and run again without hard-resetting:
```
from breakout_potentiometer import BreakoutPotentiometer
from pimoroni_i2c import PimoroniI2C
i2c = PimoroniI2C(4, 5)
pot = BreakoutPotentiometer(i2c)
```
This should now work, since the failed I2C instance was cleaned up.
Without this change, the second attempt would result in an inexplicable failure.
Since most? (many?) Pico users do not have a reset button, this trap requiring a hard-reset is pretty nasty and would likely have resulted in a support nightmare.
Whew.
Removes i2c_inst_t from constructors since it's ignored, and updated the Python bindings not to supply this argument. Instance is inferred from the supplied pins.
Removes all driver-specific SDA/SCL pin definitions and defaults.
Pin type is "uint" everywhere, but "PIN_UNUSED" is *int*_max for MicroPython compat. That's still a lot of pins!
Adds baudrate to the I2C class, and allows a driver (like Trackball) to check the baudrate is supported
This change adds a common I2C class, gathering various I2C functions into a single point of responsibility.
It's necessary for correctly managing the I2C bus pins and state across multiple devices.
* Add a common/pimoroni.hpp to list default pins for various add-ons
* Move the BG SPI Slot enum here for safe keeping
* Switch all GPIO pin references to "uint" to match Pico SDK and bring back PIN_UNUSED as UINT_MAX
Confused myself by plugging this into a BG base. It gave all the appearance of working, but the time was not counting up.
Turns out the library will happily talk to no device whatsoever and when you "set_time" it's stored in an C array and returned as if it came from the RTC.
Phil Howard
Philip Howard
ZodiusInfuser