52. QEI

52.1. Overview

The QEI project demonstrates how to use the Quadrature Encoder Interface to read motor encoder data and output it through the serial port.

  • Configuring QEI interrupts and trigger conditions

  • Reading QEI registers including Z, phase, speed and timer values

  • Using TRGM (Trigger Mux) to route encoder signals

52.2. Configurations

  • Install a serial terminal, refer to board information for serial port configuration

  • This program uses the BLM57050-1000 brushless motor from “Leisai Intelligence”. For detailed motor specifications, please visit the Leisai Intelligence website.

  • Refer to DRV-LV50A-MP1907 Motor Driver Board section for motor driver configuration

  • The QEI is configured with: - Phase count per revolution from motor specifications - Z count increment on phase count maximum - Phase comparison trigger point set to capture data at specific motor position - Positive compare flag trigger for data capture

52.3. Running the Demo

  • Power on the board and open the serial terminal

  • The program will initialize QEI and TRGM

  • When the motor shaft is rotated, QEI interrupts will be triggered and the following data will be printed: - Z count: Encoder Z signal count - Phase: Current phase position - Speed: Sum of 4 consecutive speed history samples (his0 to his3) - Timer: Timer value at capture time

> z: 0xffffff9c
> phase: 0xc200014d
> speed: 0xa0000000
> timer: 0xa8d08799

The values will change based on: - Motor rotation speed - Rotation direction - Encoder resolution - Phase count configuration