Overview
The ESC parameter group (primarily within AP_Periph firmware) configures the communication with Electronic Speed Controllers (ESCs) for the purpose of telemetry and calibration.
While the main autopilot handles motor control (via PWM or DShot), a DroneCAN node (or the autopilot itself) can listen to the ESC's serial telemetry stream to report RPM, Temperature, Voltage, and Current for each individual motor.
Key Concepts
1. ESC Telemetry
Many modern ESCs (BLHeli_32, APD, KISS) output a low-speed serial stream (typically 115200 baud) containing real-time health data.
ESC_TELEM_PORT: Selects the UART used to listen to the ESCs.ESC_TELEM_RATE: Frequency (Hz) at which this data is forwarded to the main autopilot via CAN or MAVLink.
2. ESC Calibration (ESC_CALIBRATION)
This parameter (in some firmwares) can trigger a passthrough mode to allow a PC-based configurator (like BLHeliSuite) to talk through the autopilot to the ESCs for firmware updates and tuning.
Parameter Breakdown
ESC_TELEM_PORT: Serial port index for ESC data.ESC_PWM_TYPE: (AP_Periph) Defines the output protocol to the ESC (PWM, OneShot, DShot).ESC_RATE: The update rate of the motor control signal (Hz).
Integration Guide
- Hardware: Connect the "TLM" pin from all ESCs together (usually) and wire to the RX pin of the designated
ESC_TELEM_PORT. - Enable: Set the port and rate.
- Verify: Check the
ESC_TELEMETRYorESCmessages in the DataFlash log.
Developer Notes
- Library:
Tools/AP_Periphandlibraries/AP_ESC_Telem. - Advanced: Highly integrated with the Harmonic Notch Filter (
INS_HNTCH_), which uses individual motor RPM to dynamically target vibration frequencies.