Open-source Android app for the DiKey aftermarket center-console controller.
Replaces the vendor app DiKey Smart Link (迪铠智联). Runs on DiLink 5 head units, controls DiKey lighting and climate, and provides vehicle information, ADAS settings, Sentry integration, and Pet Mode through local BYD APIs.
Note: The commercial DiKey hardware is sold as BYD Shark 6 DiKey Vehicle Intelligent Keys on Alibaba. Not affiliated with DiKey, BYD, or the seller. Use at your own risk.
| Vehicle | Status |
|---|---|
| BYD Shark 6 | Supported |
Other vehicles are untested.
- DiLink 5 head unit with USB debugging enabled
- ESP32-C3 Super Mini board — AliExpress or Amazon AU
- USB cable
1. Flash the USB bridge
On a PC in Chrome or Edge, download dikey-usb-bridge-c3.bin from the latest release, then open ESPWebTool:
- Connect — choose USB JTAG/serial debug unit. If it doesn't show up, hold BOOT while plugging it in.
- Delete every existing address slot (there will be about 4)
- Add a new slot at
0x0 - Choose
dikey-usb-bridge-c3.bin
It should look like this before clicking Program:
Then click Program.
2. Install the app
Sideload the APK from the latest release onto the head unit and launch it once.
3. Grant permissions
- Accept Allow USB debugging
- Allow the hidden-API exemption (app restarts)
- Plug the C3 board into the car's USB-C port (USB-A ports may not register)
- If USB permission doesn't pop up, unplug and replug the board while staying in the app
- If using the BLE connection instead, allow Nearby devices / Bluetooth
- Allow Open DiKey in any DiLink auto-start / run in background menu if available
Open DiKey once after each cold boot or deep sleep. A foreground listener then keeps the USB/BLE connection alive while the app is in the background (see autostart.md).
Colors — Set ambient bars (left, middle, right) and DiKey backlight with HSV wheels. Pick modes (solid / breath / blink / flow / off). Day and night profiles switch automatically from the vehicle ambient-light sensor (same signal as auto headlights / tunnels).
Button mapping — Down click keeps climate (as printed) unless remapped. Down long, up, and up long can open apps or run Android Intents (activity / broadcast).
Dials — Left dial = passenger, right dial = driver. Click to switch between temp and fan, rotate to adjust.
Vehicle info — Live dashboard for battery, range, fuel, driving data, tyre pressures, vehicle attitude, and head-unit resource usage.
ADAS — View current driver-assistance settings or save and apply a custom ELKA, LDA, AEB, and DMS profile. Long-press the ADAS tile to configure automatic application when the app starts.
Sentry — Install, update, and open the separate Strike sentry app.
Pet Mode — Keeps the display awake and periodically enforces a configurable climate profile while the vehicle is READY. Fan speed, temperature, recirculation, and wind direction can be configured; the previous climate and brightness settings are restored on exit.
Camping fridge (experimental) — The home tile defaults to the ESP32 USB bridge. Flash the updated ESP32-C3 bridge firmware as well as installing the APK (update both together: older app versions reject the new bridge capability). When the app starts, the bridge independently discovers an EVAKOOL Down Under / CoolRide fridge, subscribes to notifications and queries status every five seconds alongside its existing DiKey connection. The home tile is hidden until the fridge first delivers live readings after the app starts. It then shows the EVAKOOL logo, the left (L) and right (R) temperatures in the fridge's units (with small grey L/R labels), and Eco mode, Max mode or Switched off. The tile is the same size as the others in its row. If the fridge later disconnects, the tile stays, shows Disconnected with the reason, and offers a Reconnect button. The ESP32 fridge link stays connected while the app process runs (on any page), so readings appear immediately; the bridge drops it 35 seconds after the app stops polling or USB disconnects. Opening or reconnecting never changes fridge power, targets or mode. While the tile is hidden (e.g. when testing the Android backup), open the fridge page from Debug → Bluetooth / fridge diagnostics → Open camping fridge page.
Tap the tile to open the fridge page. The header shows the fridge's Bluetooth name (last known name while disconnected) with the transport and address. The right side starts with a Fridge power On/Off switch (turning off asks for confirmation; requires the CONTROL_V3 bridge firmware on the USB path), then a card per compartment with the current temperature and ▲ / ▼ target buttons, followed by an Eco / Max compressor-mode toggle (CONTROL_V2 or later); taps are combined and sent about a second after the last one, one change at a time, and targets/mode/power are confirmed only when the fridge reports them back (unconfirmed after 15 s). Targets are limited to -25..20 °C (-13..68 °F) by the app; this is a conservative guard, not your model's rating. The left side graphs both compartments (solid) and their targets (dashed) for the Last hour / Last day / Last week. A sample is stored once a minute while live readings arrive, in the app's private storage, and anything older than seven days is discarded; gaps appear as breaks in the line. History is recorded only while the app is running and can be cleared from More. More also contains Connection details, transport switching and the Android device selection.
The home tile also shows the fridge's supply voltage directly beneath the temperatures, above Eco/Max. Voltage is displayed in volts on both the tile and controls page: integer protocol values are tenths of a volt (138 → 13.8 V); already-decimal values are preserved.
Fridge alerts — The app posts an Android notification (channel Camping fridge alerts) when:
- the fridge had been connected and then sends no readings for more than 2 minutes (cleared automatically when it reconnects), or
- the fridge is on and a compartment's one-minute readings rise 3 times without dropping, each at least 5 °C (9 °F) above its target. A reading that stays the same doesn't break the run; any drop resets it, so a fridge still cooling down to target never alerts. The alert clears when the compartment is back within 5° of its target.
Tapping a notification opens the fridge page. Alerts need the app process running (the background listener keeps it alive). On the Android Bluetooth backup, disconnect alerts only apply while a fridge screen is open, because that path only connects then.
For the first ESP32 test, disconnect the official fridge app (temporarily turn off the phone's Bluetooth if necessary), power the fridge on nearby, connect the bridge using the existing DiKey USB connection, and open the home page. No Android Bluetooth or Location permissions are needed for the USB fridge path. Use only one matching fridge in range: the bridge automatically chooses the first matching advertisement and shows its identity in Connection details. Confirm temperatures and targets against the fridge, then exercise the DiKey dials/buttons while watching fridge readings. Test fridge power loss/recovery, USB reconnect and leaving/returning to home. Physical hardware and stable simultaneous connections still need validation; this is not a certified firmware release.
Open the fridge page and choose More > Use Android Bluetooth backup to retain the original direct-BLE path. This explicit choice is saved; there is no automatic failover that could make both radios compete for the fridge. With USB attached, the app waits for the bridge to acknowledge FRIDGE OFF before starting Android BLE. If old/unresponsive bridge firmware cannot acknowledge it, update the firmware or unplug USB before using the Android backup. Switch back using Use ESP32 USB bridge. The Android selection is retained across transport changes.
On the Android backup, select the fridge once using More > Select / change fridge. Enable head-unit Bluetooth, allow Nearby devices (Location permission and system Location on Android 11), and keep the home or fridge page visible for automatic connection/retries. The same power, ▲ / ▼ and Eco / Max controls work on this path. Both paths clear live readings after disconnect or stale status. The protocol is based on the Down Under II 2.0.0 APK (E530 service, E531 writes without response, E532 notifications); the Android backup requires usable head-unit BLE GATT, whereas ESP32 USB bypasses it.
The fridge picker shows scan progress, nearby/visible device counts, and explicit empty/error messages. Use Scan again after a scan finishes or after enabling Bluetooth/Location. If nearby devices are detected but the fridge is not listed, enable Show all nearby BLE devices to include renamed or unrecognized devices; select only your fridge. Expected DownUnder/CoolRide names or the advertised EVAKOOL service are marked as matches. Unknown devices still have to pass the EVAKOOL GATT service/property check before any commands are sent.
Tap More > Connection details on the fridge page to see the last received frame and connection error when testing. The parser accepts fragmented/coalesced newline-delimited frames, or complete CSV frames after a 500 ms notification gap. Unit codes 1 (C) and 2 (F) are accepted; unknown codes are shown as errors rather than guessed. Capture the diagnostic frame if your firmware differs. Automatic retries never resend a target change.
For head-unit scan problems, open Debug (bug icon) > Bluetooth / fridge diagnostics. It checks SDK version, OS-advertised BLE support, adapter/scanner availability, permission grants, system Location, Location AppOp and Android-reported GATT connections, alongside the DiKey connection/USB state and ESP32 fridge firmware/status, live readings and recent ESP32 fridge events. ESP32 scan (15s) lists every advertiser the bridge hears (address, RSSI, connectable, fridge match, name) without connecting to anything; ESP32 report shows the latest list. Buttons request the appropriate runtime permissions or open system settings; returning refreshes the checks. On Android 11 there is no Bluetooth runtime permission toggle: grant Location and enable system Location.
Run BLE scan (15s) counts raw advertisement callbacks before fridge-name/connectability filters, shows elapsed time, sample names/addresses/RSSI/service UUIDs and Android scan error codes, and distinguishes a scan request from confirmed reception. A request returning without exception is not proof of radio activity; zero callbacks is inconclusive, while any callback confirms BLE reception. The test stops when leaving the page and never disconnects DiKey, connects to a peripheral or sends commands. Wait 30 seconds between scan starts to avoid throttling. Use Copy or Share to export the report; review nearby device identities before sharing. Third-party BLE restrictions or inaccurate feature reporting in BYD firmware may still need ADB investigation.
Background listener — After you open Open DiKey, a foreground service keeps the USB/BLE DiKey link alive while the UI is in the background. Open the app once after power-on (see autostart.md for DiLink limitations).
In-app updates — Home gear icon → Check for updates downloads the latest open-dikey.apk from GitHub Releases.
| Button | Downward press |
|---|---|
| 1 | Climate on/off |
| 2 | A/C compressor |
| 3 | Cycle wind |
| 4 | Recirc |
| 5 | Auto |
| 6 | Front defog |
| 7 | Rear window / mirrors |
| 8 | Air only |
| 9 | Sync (driver/passenger temps) |
| 10 | Max cool |
Android paths below are relative to app/src/main/java/com/sphy/airconcontroller/.
| Path | Purpose |
|---|---|
MainActivity.kt |
Home screen |
ColorConfigActivity.kt |
Ambient + backlight |
ButtonMappingActivity.kt |
Button config |
VehicleInfoActivity.kt |
Live vehicle dashboard |
AdasActivity.kt |
ADAS profiles |
SentryActivity.kt |
Strike installer and launcher |
PetModeActivity.kt |
Pet Mode runtime |
PetModeConfigActivity.kt |
Pet Mode profile |
SettingsHubActivity.kt |
Settings and app updates |
dikey/DiKeySession.kt |
USB/BLE session |
dikey/DiKeyClimateMapper.kt |
Climate controls |
dikey/DiKeyUpMapper.kt |
App launcher |
usb/DiKeyUsbBridge.kt |
USB serial |
boot/DiKeyListenService.kt |
Background listener |
adb/AdbPermissionManager.kt |
Grants + hidden-API |
byd/Dilink5SdkInjector.kt |
OEM SDK loader |
byd/BydAcController.kt |
Climate API |
byd/BydAdasController.kt |
ADAS API |
byd/BydVehicleInfoController.kt |
Vehicle data API |
firmware/src/DiKeyUsbBridge/ |
C3 bridge firmware |
assets/Docs/vendor-re/PROTOCOL.md— DiKey BLE/USB protocolassets/Docs/Offline/— Offline docs portalassets/BYD API/— BYD Auto API V1.0.5
DiLink 5 permission and SDK loading follow BYD Trip Stats by Angelos Oikonomou and contributors.
Built with dadb.
Vendor manuals redistributed for offline use with purchased hardware; copyright remains with respective owners.
- Wheel by Asiah from Noun Project (CC BY)
- Color wheel by Fahad Hashmi from Noun Project (CC BY)
- Button by Larea from Noun Project (CC BY)
- Dial by Zach Bogart from Noun Project (CC BY)
- adas by Arijit Dey from Noun Project (CC BY)
- recording by Jonathan Wong from Noun Project (CC BY)
- Paw by Rafiico Creative Studio from Noun Project (CC BY)