BetaVTXControl

ESP32 Arduino library for controlling VTX (Video Transmitter) modules via SmartAudio and TRAMP protocols. Based on Betaflight and esp-fc implementations.

Optimized for PlatformIO development.

Features

• SmartAudio protocol support (v1, v2, v2.1) - fixed 4800 baud
• TRAMP protocol support - fixed 9600 baud
• Frequency control (5000-5999 MHz)
• Power level control (25mW - 800mW typical)
• Pit mode support
• TX-only mode (no RX needed, as per esp-fc)
• Dummy byte transmission for UART stabilization
• Non-blocking operations
• Manual protocol selection (VTX_PROTOCOL_SMARTAUDIO / VTX_PROTOCOL_TRAMP)
• CRC validation for SmartAudio
• Checksum validation for TRAMP
• Thread-safe (FreeRTOS compatible)

Installation

PlatformIO (Recommended)

Method 1: From GitHub

Add to your platformio.ini:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
lib_deps = 
    https://github.com/igorka48/BetaVTXControl.git

Method 2: Local Development

Copy the library to your project's lib/ directory.

Arduino IDE (Legacy)

1. Download the latest release
2. Sketch → Include Library → Add .ZIP Library
3. Select the downloaded file

Note: Examples are provided as .ino files for Arduino IDE compatibility, but #include <Arduino.h> is included for PlatformIO.

Hardware Connection

Important: Only TX pin (GPIO 16) is needed - VTX control wire connects to TX only.

Wiring Diagram

ESP32 GPIO 16 (TX) ────── VTX Control Wire (SmartAudio/TRAMP)
ESP32 GND ───────────────── VTX GND

Notes:

• Both protocols use half-duplex UART on a single wire
• TX-only mode: Commands sent, no response expected
• SmartAudio: 4800 baud, 8N2
• TRAMP: 9600 baud, 8N1
• Check VTX voltage level (3.3V or 5V) - use level shifter if needed

Usage

Basic Example

#include <BetaVTXControl.h>

#define VTX_TX_PIN 16  // ESP32 GPIO pin for VTX control

BetaVTXControl vtx(VTX_PROTOCOL_SMARTAUDIO); // or VTX_PROTOCOL_TRAMP

void setup() {
  Serial.begin(115200);
  
  if (vtx.begin(&Serial2, VTX_TX_PIN)) {
    vtx.setFrequency(5732);       // R3 (Raceband 3)
    delay(300);                   // IMPORTANT: Wait between commands
    vtx.setPower(200);            // 200mW
    delay(300);
    vtx.setPitMode(false);
    delay(300);
  }
}

void loop() {
  delay(100);  // TX-only: configure once in setup()
}

Debug Mode (Optional)

Enable debug output to see raw HEX commands sent to VTX:

#include <BetaVTXControl.h>

#define VTX_TX_PIN 16

BetaVTXControl vtx(VTX_PROTOCOL_SMARTAUDIO);

void setup() {
  Serial.begin(115200);
  
  // Enable debug: pass Serial as third parameter
  if (vtx.begin(&Serial2, VTX_TX_PIN, &Serial)) {
    vtx.setFrequency(5732);
    delay(300);
  }
}

void loop() {
  delay(100);
}

Debug output example:

[SmartAudio] Debug enabled
[SmartAudio] AA 55 09 02 16 64 7E
[SmartAudio] AA 55 05 01 00 C4

Important Notes:

• SmartAudio: Power is specified in mW but converted to device index (0-4)
• TRAMP: Power is sent directly in mW
• Always add 300ms delay between commands to ensure VTX processes each one
• Some VTX devices may require longer delays (500ms+)

API Reference

Initialization

BetaVTXControl vtx(VTX_PROTOCOL_SMARTAUDIO);  // or VTX_PROTOCOL_TRAMP
bool begin(HardwareSerial* serial, uint8_t txPin = 16);

Configuration Methods

Method	Parameters	Description
setFrequency(freq)	uint16_t freq	Set frequency in MHz (5000-5999)
setPower(power)	uint16_t power	Set power in mW (25, 200, 400, 600, 800)
setPitMode(enable)	bool enable	Enable/disable pit mode (low power)

Note: TX-only mode - commands are sent immediately, no response expected. Add 300ms delay between commands.

Direct Protocol Access

#include <SmartAudio.h>
SmartAudioVTX vtx;
vtx.begin(&Serial2, 16);  // TX pin

#include <TRAMP.h>
TrampVTX vtx;
vtx.begin(&Serial2, 16);  // TX pin

Protocol Details

	SmartAudio	TRAMP
Baudrate	4800 (8N2)	9600 (8N1)
Validation	CRC8 (0xD5)	Checksum
Packet Start	0xAA 0x55	0x0F
Versions	v1, v2, v2.1	-

See frequency tables for channel mappings.

Troubleshooting

VTX not responding:

• Check wiring (TX on GPIO 16, common GND)
• Verify VTX is powered
• Check voltage levels (use level shifter for 5V VTX)
• Try opposite protocol (SmartAudio ↔ TRAMP)

Commands ignored:

• VTX may be in race lock mode
• Add 300ms delays between commands
• Power cycle VTX

Power commands not working (SmartAudio):

• SmartAudio uses power index (0-4), not direct mW
• Different VTX models have different power tables
• Try setPowerByIndex(0) through setPowerByIndex(4) to find working values
• Example: vtx.setPowerByIndex(2) might be 400mW on your VTX

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push and create a Pull Request

License

MIT License - see LICENSE file for details.

Based on Betaflight VTX implementation (GPL-3.0).

Credits

• Betaflight - Original protocol implementation
• esp-fc - ESP32 flight controller implementation
• SmartAudio protocol by TBS (Team BlackSheep)
• TRAMP protocol by ImmersionRC

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions