Added definition for an upcoming Pimoroni motor driver board

[ZodiusInfuser]

Let me know if you spot any issues. Hoping to launch at the end of the week.

Also I included a NEOPIXEL alias as this was highlighted as missing on Servo 2040 (#6307)

I did also consider including constant tuples for the motor and encoder pairs, as I recently discovered they could be done in MicroPython, but this seemed a bit experimental to include in these CircuitPython definitions.

const mp_rom_obj_tuple_t motor2040_encoderA_pins = {
    {&mp_type_tuple}, 2, { MP_ROM_INT(1), MP_ROM_INT(0) },
};

STATIC const mp_rom_map_elem_t motor2040_globals_table[] = {
    { MP_ROM_QSTR(MP_QSTR_MOTOR_A), MP_ROM_PTR(&motor2040_motorA_pins) },
}

[dhalbert]

I did also consider including constant tuples for the motor and encoder pairs

You could do that, as you did here: #6208 (comment). The main issue is to make sure that if a static object has pointers to heap objects, that those pointers are included in garbage collection.

[ZodiusInfuser]

Thanks. I'm a bit pushed for time at the moment, so if I do add those tuples it's unlikely to be for this PR

[dhalbert]

Looks fine! I had a query/suggestion.

[dhalbert]

If there is going to be a library you (almost) always use with this board, you might consider putting constants like these and NUM_MOTORS in the library rather than casting them in stone.

[ZodiusInfuser]

Ah okay. There's no specific library for this board at the moment, I was just going to use the existing motor,encoder,neopixel etc libraries, as my time is stretched pretty thin with supporting C++ and Micropython. Something to consider for the future though.

[jepler]

For your reference, another case of putting a tuple of things in the board module, in this case a sequence of pins defining parallel bus:

STATIC const mp_rom_obj_tuple_t camera_data_tuple = {
    {&mp_type_tuple},
    8,
    {
        MP_ROM_PTR(&pin_GPIO13),
        MP_ROM_PTR(&pin_GPIO15),
        MP_ROM_PTR(&pin_GPIO16),
        MP_ROM_PTR(&pin_GPIO14),
        MP_ROM_PTR(&pin_GPIO12),
        MP_ROM_PTR(&pin_GPIO10),
        MP_ROM_PTR(&pin_GPIO9),
        MP_ROM_PTR(&pin_GPIO7),
    }
};
...
    { MP_ROM_QSTR(MP_QSTR_CAMERA_DATA), MP_ROM_PTR(&camera_data_tuple) },
...

[ZodiusInfuser]

Thanks for that @jepler. Which file is that in, for reference?

[jepler]

oops meant to leave the reference in the comment:

circuitpython/ports/espressif/boards/adafruit_esp32s2_camera/pins.c

Line 5 in bf2fd53

STATIC const mp_rom_obj_tuple_t camera_data_tuple = {