This software is meant to be used with the Adafruit nRF52 feather and is meant to connect to any keyboards over I2C, converting that keyboard into a bluetooth keyboard.
The keyboard should work as master, and connect to the BlueKeeb.
BlueKeeb starts assuming any bytes sent to it will be normal key_down events. If that isn't the case, and instead a media key, a modifer or a key_down event is being sent, the keyboard should send a type change byte first.
| Bit | Function |
|---|---|
| 7:4 | Has to be set to 1 to indicate a Type change byte |
| 3 | If set indicates that any further keys send, are to be released |
| 2 | Reserved for future use |
| 1:0 | The type of keycode sent after the type change |
Types are currently:
| Value | Type |
|---|---|
| 0 | Normal key |
| 1 | Modifier |
| 2 | Media |
| 3 | unused |
Where media technically is just "consumer page" of the HID standard
Releasing keys are done by setting the release bit in the type change byte and then sending your keycode
If the correct type is set, send the HID bytes you wish to press / release. Keep in mind that BlueKeeb is 6KRO, keep track yourself, or check the status byte to see if ROLL_OVER has been hit.
If the correct type is set, send the value corrosponding to the modifer
| Value | Modifier |
|---|---|
| 0 | left control |
| 1 | left shift |
| 2 | left alt |
| 3 | left GUI (Win/Apple/Meta key) |
| 4 | right control |
| 5 | right shift |
| 6 | right alt |
| 7 | right GUI |
If the correct type is set, send the value corrosponding to the media key
Only common functions are listed here, for a full consumer page, consult the HID standard
| Value | Function |
|---|---|
| 0x30 | Power |
| 0x31 | Reset |
| 0x32 | Sleep |
| 0xB0 | Play |
| 0xB1 | Pause |
| 0xB3 | Fast Forward |
| 0xB4 | Rewind |
| 0xB5 | Scan Next Track |
| 0xB6 | Scan Previous Track |
| 0xB7 | Stop |
| 0xCD | Play/Pause |
| 0xE2 | Mute |
| 0xE9 | Volume+ |
| 0xEA | Volume- |
The keyboard can check the status of the BlueKeeb any time it wants, but it makes the most sense to check after sending a key.
Simply send an I2C request for 1 byte, and BlueKeeb will send it's status byte
| BIT | Meaning | Note |
|---|---|---|
| 7 | Unused | |
| 6 | Unused | |
| 5 | Unused | |
| 4 | Unused | |
| 3 | Unused | |
| 2 | Key already released | Bit reset when status byte is read |
| 1 | Key already pressed | Bit reset when status byte is read |
| 0 | ROLL OVER, too many keys pressed, key_presses ignored | Bit is reset when key wasn't ignored |