Quadrant Engine Connection and Configuration Guide

Zero-One Flight Controller + Quadrant Engine Connection and Configuration Guide

This guide applies to the Zero-One flight controller and Quadrant engine that have been properly adapted. Prerequisites are as follows:

1. Firmware version must be 4.4.0 or higher
2. Lua script support must be enabled in the flight controller firmware

1. Hardware Wiring

The Quadrant engine uses the RS422 communication protocol and requires an additional RS422 to TTL converter module for level shifting.

Wiring sequence:

Engine ECU <--> RS422 to TTL Module <--> Any free serial port on the flight controller

Note: Please purchase and prepare the RS422 to TTL module yourself.

2. Driver Script Upload and Enable

2.1 Upload Lua Script

Place the driver Lua script into the microSD card of the flight controller at the following path:

APM/SCRIPTS/

Tip: Uploading via MAVFTP is also acceptable and has the same effect.

2.2 Set Key Flight Controller Parameters

Connect to a ground station (such as Mission Planner or QGroundControl) and set the following parameters:

Note: Replace n in SERIALn_PROTOCOL with the actual serial port number (e.g., SERIAL2, SERIAL3, etc.).

2.3 Reboot the Flight Controller

After setting the parameters, reboot the flight controller to apply the changes and reload the scripts.

3. Post-Run Parameter Adjustments

After reboot, new parameters prefixed with EP_ will appear in the ground station parameter list. Configure them according to the table below:

Important notes on throttle lock:

• When the PWM of the channel mapped by EP_THR_FUNCTION (e.g., RC6) is greater than 1600: throttle control is allowed, engine runs normally.
• When the PWM of that channel is below 1600: throttle is forced to zero, engine immediately shuts down (safety protection).

4. Ground Station Monitoring Information

Once configured successfully, the ground station will receive EFI_STATUS MAVLink messages containing:

• RPM
• Cylinder head temperature
• Injection timing
• Engine load
• Fuel consumption rate
• Throttle position
• Atmospheric pressure
• ECU voltage

5. Common Issues and Tips

• Ensure the script file is correctly placed in the APM/SCRIPTS/ directory and the filename is correct.
• If EP_ parameters do not appear after reboot, check that SCR_ENABLE=1 and that the script loaded successfully.
• If the engine fails to start, first check whether the PWM input on the channel mapped by EP_THR_MIN is greater than 1600.
• For initial debugging, it is recommended to test the throttle lock logic without the propeller installed to ensure safety.