Bluetooth Car Controller RC

Bluetooth Car Controller turns your phone into a proper cockpit for Arduino-based RC vehicles. It speaks classic Bluetooth RFCOMM (Serial Port Profile) to your HC-05, HC-06 or ESP32 module, so the single-byte commands your sketch already understands arrive exactly as you wrote them. No account, no cloud, no extra hardware bridge.

WHAT YOU GET

• A driving cockpit, not a form. A large D-pad for forward, back, left and right, a horn in the middle of your thumb's reach, and a 10-step speed meter you can read at a glance.
• One-tap toggles for the things a real car has: front lights, rear lights, all LEDs, left and right turn signals, park brake and lock.
• Live connection status. A green "Connected" pill while the socket is open, a clear failure dialog with Retry when it is not.
• Portrait and landscape. Landscape splits into two columns — movement on one side, speed and auxiliary controls on the other — so both thumbs stay where they belong.
• Light theme, dark theme, or follow your system.
• English, Turkish and Arabic, including full right-to-left layout, or just follow the device language.

HOW TO CONNECT

1. Flash firmware that exposes the standard SPP service UUID 00001101-0000-1000-8000-00805F9B34FB. Most HC-05 and HC-06 modules do this out of the box.
2. Pair the module once from Android Settings, under Connected devices and Bluetooth.
3. Open Bluetooth Car Controller, allow Bluetooth when Android asks, tap your vehicle, and drive as soon as the status pill turns green.

THE COMMAND SET

Movement is press-and-hold: forward sends F, back sends B, left sends L, right sends R, and releasing any of them sends the neutral character S. The horn sends Z while held and z on release.

Toggles pair upper and lower case: park H and h, right signal U and u, left signal V and v, all LEDs P and p, front lights W and w, rear lights E and e. Lock sends K; unlock sends k followed by a space, matching the behaviour of older Arduino sketches.

The speed control transmits one raw byte from 0 to 9, ten discrete levels, which your firmware maps to PWM however you like. Every command is documented on the in-app Command reference screen, so you can check a byte without leaving the controller.

PERMISSIONS, PLAINLY

On Android 12 and newer the app asks for BLUETOOTH_CONNECT, which is what lets it open an RFCOMM socket to hardware you already trusted by pairing. Older releases use the legacy Bluetooth permissions. There is no location permission and no background access, because listing already-paired devices does not need either.

PRIVACY

Your theme and language choices are stored on your phone and nowhere else. This build ships no analytics SDK, no advertising SDK and no crash reporting SDK. The app never collects, transmits or sells anything.

BEFORE YOU BUILD

You are responsible for the wiring, power supply, motor driver and firmware safety of your vehicle — timeouts, failsafe stop and the rest. This app is a UART-over-RFCOMM remote control; it cannot diagnose faulty electronics or a mismatched baud rate. If the bytes your sketch expects differ from the ones listed above, adapt either side. The protocol is small and fully documented.

Built with Kotlin and Jetpack Compose, Material 3, minimum Android 9.