ESP Pixhawk Arm (ESP32/ESP8266)

A tiny web UI and HTTP API to ARM/DISARM a Pixhawk-compatible autopilot via MAVLink using an ESP32 or ESP8266.

• Single sketch for both platforms with conditional compilation
• Async web stack with Server-Sent Events for instant status updates
• Wi-Fi provisioning via WiFiManager, mDNS, and OTA updates
• Flight mode control (RTL, Stabilize, Alt Hold)
• MAVLink command acknowledgment feedback

Features

• Web UI (served from flash) with ARM/DISARM buttons and flight mode controls
• API:
  • GET /status → { "armed": bool, "mode": number }
  • POST /arm → { "ok": true }
  • POST /disarm → { "ok": true }
  • POST /mode/rtl → { "ok": true } (Return to Launch)
  • POST /mode/stabilize → { "ok": true } (Stabilize mode)
  • POST /mode/alt_hold → { "ok": true } (Altitude Hold)
  • SSE GET /events → events status and ack with command feedback
• Reads ARM state from MAVLink HEARTBEAT (no optimistic toggles)
• Displays MAVLink command acknowledgments in UI
• Works on ESP32 (HardwareSerial2) and ESP8266 (SoftwareSerial)
• Optional AP-only mode with fixed IP (172.217.28.1)

Hardware

• Pixhawk serial telemetry → ESP UART
• Default pins:
  • ESP32: RX=GPIO16, TX=GPIO17 (UART2)
  • ESP8266: RX=GPIO5, TX=GPIO4 (SoftwareSerial)
• Override at compile time:
  • -DMAV_RX_PIN=<gpio> -DMAV_TX_PIN=<gpio>

Dependencies

Install via Arduino Library Manager or PlatformIO:

• ESPAsyncWebServer
• AsyncTCP (ESP32) or ESPAsyncTCP (ESP8266)
• WiFiManager (tzapu)
• ArduinoOTA
• mDNS (ESPmDNS on ESP32, ESP8266mDNS on ESP8266)
• mavlink (Arduino MAVLink headers)

Build

• Open esp-pixhawk-arm.ino in Arduino IDE
• Select board (ESP32 or ESP8266)
• Ensure dependencies are installed
• Flash; on first boot WiFiManager captive portal appears (SSID like esp32-pixhawk or esp8266-pixhawk)

AP-only mode (optional)

Uncomment #define AP_ONLY_MODE in the sketch to enable access-point-only mode:

• Fixed IP: 172.217.28.1
• AP SSID: pixhawk32-ap or pixhawk8266-ap
• Password: 12345678

Usage

• Open the device in a browser:
  • ESP32: http://pixhawk32.local/ (or http://172.217.28.1/ in AP-only mode)
  • ESP8266: http://pixhawk8266.local/ (or http://172.217.28.1/ in AP-only mode)
• Use UI buttons to ARM/DISARM or change flight modes
• Command acknowledgments appear as temporary messages in the UI
• All flight mode changes and ARM/DISARM commands are confirmed via MAVLink

Security

• Endpoints are open by default. For production, add basic auth or a PIN check to POST /arm and /disarm handlers.

Notes

• On ESP8266, SoftwareSerial is used; for robust telemetry consider ESP32 with HardwareSerial.
• UI is embedded and served from program memory; no filesystem required.

License

This project is licensed under the MIT License (see LICENSE).