Building Grid
Ricoh publishes no SDK, no API documentation, and has no developer program for the GR series. Everything Grid does with the camera is built on the work of a small community that reverse-engineered the protocol. On that foundation I built an app in Swift/SwiftUI, verified on real hardware.
The story
The GR communicates over two channels, and Grid uses them exactly the way the official Ricoh app does:
- Bluetooth Low Energy (BLE) is the control channel. The camera
advertises itself as
GR_XXXXXX. After pairing (a standard iOS bond; the camera needs to be in pairing mode once), the app can use GATT characteristics to read the battery and storage, power the camera on and off, push GPS positions for geotagging. And, crucially, it can read the camera's own WiFi credentials. - WiFi is the data channel. The camera is an access point (no internet).
Grid reads the SSID and passphrase over BLE, has iOS join the network
(
NEHotspotConfiguration), and then talks to a simple HTTP server at192.168.0.1: photo listings, thumbnails, downloads, and a WebSocket for live updates.
Sources
None of this came from Ricoh. dm-zharov mapped the full BLE GATT tree of the GR II/III by sniffing traffic between the camera and the official app. clyang's GRsync and adriantache's GReat-Image-Downloader independently confirmed the same WiFi HTTP endpoints in their own desktop tools.
| Person | Source |
|---|---|
| dm-zharov | github.com/dm-zharov/ricoh-gr-bluetooth-api |
| clyang | github.com/clyang/GRsync |
| adriantache | github.com/adriantache/GReat-Image-Downloader |
What about the GR IV?
For the GR IV there is nothing at all. No documentation, no
reverse-engineering. Grid's GR IV profile therefore starts as an exact copy
of the GR III profile, with a diagnostics screen in the app that can dump
the full GATT tree of a connected camera to spot differences. In practice
the GR IV (firmware 1.11) turns out to be compatible: the same UUIDs, the
same HTTP endpoints, with two known differences. The bulk
/v1/photos/infos listing is missing (so Grid fetches per-photo info
lazily), and there are two storages (internal + SD, via the
?storage= parameter).
All Ricoh codes in use
BLE Services (GR II/III, verified on GR IV)
| Service | UUID |
|---|---|
| Camera Information | 6FE9D605-3122-4FCE-A0AE-FD9BC08FF879 |
| Camera (power/status) | 4B445988-CAA0-4DD3-941D-37B4F52ACA86 |
| Shooting | 9F00F387-8345-4BBC-8B92-B87B52E3091A |
| WLAN Control | F37F568F-9071-445D-A938-5441F2E82399 |
| Bluetooth Control | 0F291746-0C80-4726-87A7-3C501FD3B4B6 |
| GPS Control | 84A0DD62-E8AA-4D0F-91DB-819B6724C69E |
| Device Information | 9A5ED1C5-74CC-4C50-B5B6-66A48E7CCFF1 |
BLE Device information (read)
| Characteristic | UUID | Use in Grid |
|---|---|---|
| Bluetooth Device Name | 97E34DA2-2E1A-405B-B80D-F8F0AA9CC51C | Display name |
| Firmware Revision | B4EB8905-7411-40A6-A367-2834C2157EA7 | Firmware version (update check) |
| Manufacturer Name | F5666A48-6A74-40AE-A817-3C9B3EFB59A6 | Info |
| Model Number | 35FE6272-6AA5-44D9-88E1-F09427F51A71 | GR III/IV detection |
| Serial Number | 0D2FC4D5-5CB3-4CDE-B519-445E599957D8 | Info |
| MAC Address | 1C5C6C55-8E57-4B32-AD80-B124AE229DEC | Info |
BLE Camera status (read/write/notify)
| Characteristic | UUID | Use in Grid |
|---|---|---|
| Camera Power | B58CE84C-0666-4DE9-BEC8-2D27B27B3211 | Read status; wake the camera (write 01) |
| Operation Mode | 1452335A-EC7F-4877-B8AB-0F72E18BB295 | Read and set Capture/Playback |
| Battery Level | 875FC41D-4980-434C-A653-FD4A4D4410C4 | Battery % + charging state (byte 1 = level, byte 2 = source) |
| Storage Information | A0C10148-8865-4470-9631-8F36D79A41A5 | Free space internal/SD (binary blob) |
| Camera Service Notification | FAA0AEAF-1654-4842-A139-F4E1C1E722AC | Push notifications from the camera |
| Operation Request | 559644B8-E0BC-4011-929B-5CF9199851E7 | (Defined, unused, remote shutter candidate) |
| Date Time | FA46BBDD-8A8F-4796-8CF3-AA58949B130A | Sync the camera clock (Settings option) |
BLE Geotagging (GPS Control service)
| Characteristic | UUID | Use in Grid |
|---|---|---|
| GEO Tag | A36AFDCF-6B67-4046-9BE7-28FB67DBC071 | Geotagging on/off on the camera (1 byte) |
| GPS Information | 28F59D60-8B8E-4FCD-A81F-61BDB46595A9 | Write GPS fix (32-byte payload, see below) |
BLE WiFi bridge (WLAN Control service)
The heart of the connection:
| Characteristic | UUID | Use in Grid |
|---|---|---|
| WLAN Network Type | 9111CDD0-9F01-45C4-A2D4-E09E8FB0424D | Turn the AP on (write accessPoint) |
| WLAN SSID | 90638E5A-E77D-409D-B550-78F7E1CA5AB4 | Read network name (e.g. "GR wifi") |
| WLAN Passphrase | 0F38279C-FE9E-461B-8596-81287E8C9A81 | Read WiFi password |
| WLAN Channel | 51DE6EBC-0F22-4357-87E4-B1FA1D385AB8 | (Defined, unused) |
BLE Bluetooth behavior (Bluetooth Control service)
| Characteristic | UUID | Use in Grid |
|---|---|---|
| BLE Enable Condition | D8676C92-DC4E-4D9E-ACCE-B9E251DDCC0C | Configure "Always on" standby (Settings) |
| Paired Device Name | FE3A32F8-A189-42DE-A391-BC81AE4DAA76 | (Defined, unused) |
BLE Value encodings
- Enums (power, mode, network type, …): one signed byte (
Int8rawValue). - Strings (SSID, names): UTF-8, NUL-padded at the end.
- Battery: byte 1 = level (0–100), optional byte 2 = power source (battery / AC adapter).
- GPS payload (32 bytes, written to GPS Information):
| Bytes | Contents |
|---|---|
| 0–7 | Latitude, float64 big-endian |
| 8–15 | Longitude, float64 big-endian |
| 16–23 | Altitude, float64 big-endian |
| 24–25 | Year, uint16 little-endian |
| 26–30 | Month, day, hour, minute, second (1 byte each, UTC) |
| 31 | Datum: 0 = WGS84 |
BLE Scanning
No advertised service UUID is known; Grid scans by name prefix:
GR, RICOH, PENTAX.
WiFi HTTP API (http://192.168.0.1:80)
| Endpoint | Use in Grid |
|---|---|
GET /v1/ping | Reachability check (connect + health check) |
GET /v1/props | Full property dump (Info screen) |
GET /v1/photos | Photo list (directories + files) |
GET /v1/photos?storage=in|sd | Photo list per storage (GR IV: internal + SD) |
GET /v1/photos/<dir>/<file> | Full file (JPG/DNG/MOV download) |
…?size=thumb | Thumbnail (grid) |
…?size=view | Screen resolution (viewer) |
GET /v1/photos/<dir>/<file>/info | Per-photo metadata: date, exposure, GPS |
ws://192.168.0.1/v1/changes | WebSocket: live pushes (battery level, among others) |
Downloads use a keep-alive TCP connection on the same port, so a batch doesn't pay a handshake per file.