Overview

The DSHOT parameter group (often appearing as MOT_PWM_TYPE options or SERVO_BLH_ in older setups) configures the DShot digital motor protocol.

DShot is a digital protocol for ESCs that is faster, more robust against noise, and requires no calibration (unlike PWM/OneShot).

Key Concepts

1. Protocol Speed

DShot comes in varying speeds:

• DShot150: 150 kbit/s. Slowest, most robust against noise/long wires.
• DShot300: 300 kbit/s. Standard.
• DShot600: 600 kbit/s. Fast.
• DShot1200: 1200 kbit/s. Very fast, requires high-quality wiring and F4/F7/H7 processors.

2. Bidirectional DShot

Allows the ESC to send RPM telemetry back down the signal wire. This is critical for the Harmonic Notch Filter.

Parameter Breakdown

• DSHOT_RATE: 0=Disabled, 150, 300, 600, 1200.
• DSHOT_ESC: Bitmask to select which outputs use DShot.

Integration Guide

1. Set Type: Set MOT_PWM_TYPE = 4 (DShot150) or 6 (DShot600).
2. Enable: Configure the SERVOx_FUNCTION to Motors.
3. No Cal: Do not perform ESC calibration. The endpoints are fixed (1000-2000 digital).

Developer Notes

• Library: libraries/AP_HAL_ChibiOS (RCOutput)
• Requirement: Hardware timer support (DMA). Not all pins on all boards support DShot. Check hwdef.dat or the "Alt Config" documentation.