pulse_encoder Example

Source path: example\rt_device\pulse_encoder

Supported Platforms

The example can run on the following development boards.

sf32lb58-lcd_n16r64n4

Overview

Pulse encoders can accurately measure the position of rotating shafts. Each rotation by a certain angle generates a pulse signal from the encoder. By counting these pulses, the current position of the rotating shaft can be determined.
GPtimer encoder mode example where external pulse encoder controls timer CNT increment/decrement

Example Usage

Hardware Requirements

Before running this example, you need to prepare a development board supported by this example

menuconfig Configuration

Enable timer:

Example Usage

Compilation and Programming

Switch to the example project directory and run the scons command to execute compilation:

scons –board=sf32lb58-lcd_n16r64n4 -j8

Switch to the example project/build_xx directory and run download.bat

build_sf32lb58-lcd_n16r64n4_hcpu\download.bat

For detailed steps on compilation and downloading, please refer to the relevant introduction in Quick Start.

Read GPtimer cnt value controlled by external device increment/decrement every second

Example Output Results Display:

log output:

encoder_example_init!
succeed encoder_example_init
Start Get_count!
encoder_count:0
encoder_count:2
encoder_count:5
encoder_count:-4
msh />

This example uses polling method to read cnt value every second

encoder channel selection parameter modification

Form Factor Name	GPTIMx_CHx	Pin (Physical Position)
525
	GPTIM1_CH1	PAD_PA24 (19)
	GPTIM1_CH2	PAD_PA25 (21)
587:
	GPTIM1_CH1	PAD_PA82 (CONN2 22)
	GPTIM1_CH2	PAD_PA51 (CONN2 28)

#ifdef SF32LB52X    
    HAL_PIN_Set(PAD_PA24, GPTIM1_CH1, PIN_PULLUP, 1);
    HAL_PIN_Set(PAD_PA25, GPTIM1_CH2, PIN_PULLUP, 1);
#elif defined SF32LB58X
    HAL_PIN_Set(PAD_PA82, GPTIM1_CH1, PIN_PULLUP, 1);
    HAL_PIN_Set(PAD_PA51, GPTIM1_CH2, PIN_PULLUP, 1);
#endif

Note:

For 52x chips, can be configured to any IO with PA_TIM function as encoder channel
The last parameter of HAL_PIN_Set is hcpu/lcpu selection, 1: select hcpu, 0: select lcpu

Exception Diagnosis

If the expected log doesn’t appear and rotation cannot increment/decrement cnt, you can troubleshoot from the following aspects:

Whether hardware connection is normal
Whether pin configuration is correct

Reference Documentation

For rt_device examples, the RT-Thread official website documentation provides more detailed explanations, you can add webpage links here, for example, refer to RT-Thread’s RTC documentation

Update Log

Version	Date	Release Notes
0.0.1	10/2024	Initial version
0.0.2	12/2024	2.0