18.11. GPTMR QEI MODE

18.11.1. Overview

This example project demonstrates the QEI mode function of the timer, supporting QEI UD mode, AB mode, and PD mode.

18.11.2. Board Setting

  • Use two capture channels of GPTMR, with ch0 and ch1 in one group and ch2 and ch3 in the other group.

  • Connect the encoded signal to the capture pin of GPTMR, with 2 channels.

18.11.3. Running the example

  • Run the project and execute the timer QEI mode function. The serial terminal outputs the following information, and the user inputs 0-2 to select the QEI working mode.

---------------------------------------------------------------
*                                                             *
*                       GPTMR QEI DEMO                        *
*                                                             *
* 0 - ud mode                                                 *
* 1 - ab mode                                                 *
* 2 - pd mode                                                 *
*-------------------------------------------------------------*

  • After selecting the mode, output phcnt data every 1 second

* 1 - ab mode                                                 *
qei_phcnt: 0
qei_phcnt: 0
qei_phcnt: 8
qei_phcnt: 16
qei_phcnt: 40
qei_phcnt: 56
qei_phcnt: 80