esp32 pwm

手上有個42步進電機，結(jié)合ESP32開發(fā)板搞騰一下，讓步進電機轉(zhuǎn)起來。

電機驅(qū)動芯片在小板上，啥型號就不知道了，芯片的pin圖：

ESP32上有針對電機使用的pwm，在數(shù)據(jù)手冊上有說明：

下面看下具體使用。開發(fā)環(huán)境自行補腦，利用esp-idf\examples\peripherals\mcpwm 目錄下有針對四種類型的電機pwm案例，這次使用的是兩相四線步進電機，我在mcpwm_servo_control下進行修改的。

代碼：

/* servo motor control example

This example code is in the Public Domain (or CC0 licensed, at your option.)

Unless required by applicable law or agreed to in writing, this

software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR

CONDITIONS OF ANY KIND, either express or implied.

*/

#include

#include "freertos/FreeRTOS.h"

#include "freertos/task.h"

#include "esp_attr.h"

#include "freertos/queue.h"

#include "driver/gpio.h"

#include "driver/mcpwm.h"

#include "soc/mcpwm_reg.h"

#include "soc/mcpwm_struct.h"

//You can get these value from the datasheet of servo you use, in general pulse width varies between 1000 to 2000 mocrosecond

#define SERVO_MIN_PULSEWIDTH 1000 //Minimum pulse width in microsecond

#define SERVO_MAX_PULSEWIDTH 2000 //Maximum pulse width in microsecond

#define SERVO_MAX_DEGREE 90 //Maximum angle in degree upto which servo can rotate

static void mcpwm_example_gpio_initialize()

{

printf("initializing mcpwm servo control gpio......\n");

mcpwm_gpio_init(MCPWM_UNIT_0, MCPWM0A, 15);

mcpwm_gpio_init(MCPWM_UNIT_1, MCPWM1A, 16);

}

/**

* @brief Configure MCPWM module

*/

void mcpwm_example_servo_control(void *arg)

{

//1. mcpwm gpio initialization

mcpwm_example_gpio_initialize();

//2. initial mcpwm configuration

printf("Configuring Initial Parameters of mcpwm......\n");

mcpwm_config_t pwm_config;

pwm_config.frequency = 100; //frequency = 50Hz, i.e. for every servo motor time period should be 20ms

pwm_config.cmpr_a = 50.0; //duty cycle of PWMxA = 0

pwm_config.cmpr_b = 50.0; //duty cycle of PWMxb = 0

pwm_config.counter_mode = MCPWM_UP_COUNTER;

pwm_config.duty_mode = MCPWM_DUTY_MODE_0;

mcpwm_init(MCPWM_UNIT_0, MCPWM_TIMER_0, &pwm_config); //Configure PWM0A & PWM0B with above settings

vTaskDelay(5000);

pwm_config.duty_mode = MCPWM_DUTY_MODE_1;

mcpwm_init(MCPWM_UNIT_1,MCPWM_TIMER_1, &pwm_config); //Configure PWM0A & PWM0B with above settings

while (1)

{

}

}

void app_main()

{

printf("intializing test signal...\n");

gpio_config_t gp;

gp.intr_type = GPIO_INTR_DISABLE;

gp.mode = GPIO_MODE_OUTPUT;

gp.pin_bit_mask = GPIO_SEL_12;

gpio_config(&gp);

gpio_set_level(GPIO_NUM_12, 1); //Set high

printf("Testing servo motor.......\n");

xTaskCreate(mcpwm_example_servo_control, "mcpwm_example_servo_control", 4096, NULL, 5, NULL);

}