This is a BLE implementation for the NRF52840 that acts like a BLE (Bluetooth Low Energy) remote for the Sony Alpha series that support the BLE remotes similar to JJC-RMT-P1BT. I've tried this on a Sony A7 III but from my understanding it should work with ZV-1, RX100VII, ZV-E10, A7C, A6100, A6600, A1, A7RIV, A7SIII, A9II, 6400 and A7RIII as well.
Specifically this code runs on the Adafruit NRF52840 Express which costs about $25. The repo is a PlatformIO project meaning if you open this it should handle dependencies and the toolchain to program your NRF52840. Currently the code will try to pair with whatever camera is open for pairing (described further down) and save that pairing and then automatically reconnect to that camera when avaliable. There is prob better ways of solving this but yeah, took the easy route here.
When trying to discover the camera, you have to specifically scan for the "manufacturer data" as Sony uses this to indicate state etc for the camera. So for example an advertistment header might look like this: 0x2D, 0x01, 0x03, 0x00, 0x64, 0x00, 0x45, 0x31, 0x22, 0xEF, 0x00. Decoding this you get:
| Code | Meaning |
|---|---|
| 2d 01 | Sony Corporation Company Identifier (0x012D) |
| 03 00 | Camera |
| 64 | Protocol Version |
| 00 | ??? |
| 45 31 | Model Code |
| 22 EF 00 | <tag> CODE </tag> |
The interesting part here is 0x22 0xEF 0x00 which indicates that the camera is open to pairing. If the camera is not in pairing mode you will get 0x22 0xAF 0x00 instead.
We are specifically interested in consuming the 8000FF00-FF00-FFFF-FFFF-FFFFFFFFFFFF service which contains two characteristics.
This is what I initially thought:
| Code | Description |
|---|---|
| 0x0106 | Shutter released |
| 0x0107 | Transitioning to focus |
| 0x0108 | Focus held |
| 0x0109 | Shutter fully pressed |
However Greg Leeds did a better job reversing this:
| Code | Description |
|---|---|
| 0x0107 | Focus Down |
| 0x0106 | Focus Up |
| 0x0109 | Shutter Down |
| 0x0108 | Shutter Up |
| 0x0115 | AutoFocus Down |
| 0x0114 | AutoFocus Up |
| 0x026d20 | Zoom In Down |
| 0x026c00 | Zoom In Up |
| 0x026b20 | Zoom Out Down |
| 0x026a00 | Zoom Out Up |
| 0x0121 | C1 Down |
| 0x0120 | C1 Up |
| 0x010e | Toggle Record |
| 0x024720 | Focus In? Down |
| 0x024600 | Focus In? Up |
| 0x024520 | Focus Out? Down |
| 0x024400 | Focus Out? Up |
| Code | Meaning |
|---|---|
| Focus | |
| 0x02 3F 00 | Lost |
| 0x02 3F 20 | Acquired |
| Shutter | |
| 0x02 A0 00 | Ready |
| 0x02 A0 20 | Shutter active |
| Recording | |
| 0x02 D5 00 | Recording stopped |
| 0x02 D5 20 | Recording started |