Add Mikoto board

[mrninhvn]

Board/Shield Check-list

• This board/shield is tested working on real hardware
• Definitions follow the general style of other shields/boards upstream (Reference)
• .zmk.yml metadata file added
• Proper Copyright + License headers added to applicable files (Generally, we stick to "The ZMK Contributors" for copyrights to help avoid churn when files get edited)
• General consistent formatting of DeviceTree files
• &pro_micro used in favor of &pro_micro_d/a if applicable

Source: https://github.com/zhiayang/mikoto

[petejohanson]

Thanks! A few thoughts/questions/changes.

[petejohanson]

These seem to exactly match the nRFMicro pins. Are these actually the correct pins used for the i2c for the pro-micro locations?

[mrninhvn]

ahh sr, i wil fix that

[petejohanson]

Same question.

[petejohanson]

There's no 32K xtal on the Mikoto?

[mrninhvn]

it has 32k

[petejohanson]

Then this line and the line above it should be removed. With this in place, Zephyr will use the internal RC for the 32khz timing, which is less energy efficient than using the actual xtal. You should test BLE functionality again, with a fresh build after removing your build directory, to be sure the hardware still works after the change.

Thanks.

[petejohanson]

Interesting that this is firmware controllable, nice! Instead of this section like this, we should add a Kconfig choice that allows selecting the charger value, something like:

choice BOARD_MIKOTO_CHARGER_CURRENT
    prompt "Charge current to supply to attached batteries"

config BOARD_MIKOTO_CHARGER_CURRENT_100MA
    bool "100mA charge current"

config BOARD_MIKOTO_CHARGER_CURRENT_250MA
    bool "250mA charge current"

config BOARD_MIKOTO_CHARGER_CURRENT_NONE
    bool "Disable charge current"

endchoice

The order is important, the first config item in the choice is the default.

[petejohanson]

Minor tweak.

[petejohanson]

A few minor follow ups. Thanks again!

[petejohanson]

Thanks!