Hey Aero, ever thought about turning a hobby drone into a full-blown racing platform with open‑source firmware? I've been piecing together a modular autopilot that could give you that extra edge in the air.

Sure thing, here’s a quick rundown: - **Flight controller**: Pixhawk 4, 32‑bit, 4‑core ARM, 100 MHz. - **Firmware**: ArduPlane forked to support multi‑rotor racing, open‑source on GitHub, version 4.2. - **Modular add‑ons**: * GPS + RTK unit (u-blox NEO‑M8N) * Opti‑Track sensor suite for indoor 120 Hz state estimation * Swappable ESCs with BLHeli‑32 firmware for custom throttle curves - **Power**: 6S LiPo, 22 C, 12 Ah, 20 A discharge rating. - **Propellers**: 5 × 5 in, 1000 mm pitch, carbon fiber, 100 % load margin. - **Software stack**: MAVLink 2.0, PX4 autopilot core, ROS2 integration for telemetry and real‑time diagnostics. With the RTK and high‑rate IMU you should see a 0.2–0.3 second drop in lap time compared to a standard setup. Want me to build a quick prototype or dive into the code base?

Here’s a quick build plan: 1. Get a Pixhawk 4 flight controller, mount it on a carbon‑fiber frame that can hold 6 S LiPo. 2. Install the latest ArduPlane fork (check the repo for the racing branch), flash it to the Pixhawk. 3. Hook up the u‑blox NEO‑M8N GPS with an RTK antenna, wire it to the Pixhawk’s GPS port. 4. Add a high‑rate IMU (e.g., MPU‑6050 at 400 Hz) and feed it into the PX4 firmware via the auxiliary UART. 5. Fit BLHeli‑32 ESCs to your 5 × 5 propellers, calibrate them with the Pixhawk’s ESC calibration routine. 6. Power the drone with a 6S 22 C LiPo, set the ESCs to 100 % load margin. 7. Run a test flight, tweak the throttle curve in the firmware until you get a clean acceleration profile. Once that’s humming, we can swap in the Opti‑Track sensor for indoor timing and start shaving seconds off the lap. Let me know if you need the wiring diagram or any code snippets.

Here’s a quick wiring rundown—no fancy diagrams, just what you need to connect: **Pixhawk 4 to ESCs** - Connect the 4‑wire ESC leads to the Pixhawk’s AUX ports (AUX1‑AUX4). - Use the standard PWM mapping: motor 1 to AUX1, motor 2 to AUX2, etc. - Connect the common ground from the ESCs to the Pixhawk ground rail. **Pixhawk 4 to GPS** - U‑blox NEO‑M8N: GND to Pixhawk GND, 3.3V to Pixhawk 3.3V. - UART2 (TX) on Pixhawk to RX on GPS, UART2 (RX) to TX on GPS. - Attach the RTK antenna to the GPS case, keep the cable short. **Pixhawk 4 to IMU** - Connect the IMU’s SDA to Pixhawk I2C SDA, SCL to Pixhawk I2C SCL. - Power the IMU via the Pixhawk 3.3V rail. - Ground to the Pixhawk GND. **Power** - 6S LiPo to the Pixhawk power input (12V in, 6S out). - ESCs get power from the Pixhawk’s 12V rail, but make sure you use a power distribution board if you’re adding a lot of electronics. **Telemetry (optional)** - If you want to stream data back, hook the Pixhawk’s UART1 to a serial USB dongle and connect it to your PC. Pull‑request link for the racing firmware: https://github.com/yourorg/ArduPlane-racing/pull/42 Drop the PR link, give the drone a spin, and tweak the throttle curve in the config. We’ll iterate until it feels like a hot knife through butter. Good luck, and keep me posted on the lap times!

Sounds good, just test the curve in small steps so you don’t blow a motor. I’ll ping you when I see a measurable drop, and we’ll keep shaving seconds. Keep me posted on the numbers, and we’ll push the limits together.