2008f4d88c
1. Name change from chopper to carrier, block diagram update, minor changes to example codes 2. mcpwm_reg.h changed, brought uniformity in comments, worked on suggestions, duty to accept float. Some name changes! 3. Minor readme changes and Indetation 4. Minor change: move mcpwm_reg.h and mcpwm_struct.h to new path 5. Minor change: addition of BLDC example code and Readme 6. Name changed from epwm to mcpwm 7. Improve the reg name in mcpwm_struct.h 8. Name change chopper>carrier, deadband>deadtime
88 lines
3.1 KiB
C
88 lines
3.1 KiB
C
/* servo motor control example
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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#include <stdio.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "esp_attr.h"
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#include "driver/mcpwm.h"
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#include "soc/mcpwm_reg.h"
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#include "soc/mcpwm_struct.h"
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//You can get these value from the datasheet of servo you use, in general pulse width varies between 1000 to 2000 mocrosecond
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#define SERVO_MIN_PULSEWIDTH 1000 //Minimum pulse width in microsecond
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#define SERVO_MAX_PULSEWIDTH 2000 //Maximum pulse width in microsecond
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#define SERVO_MAX_DEGREE 90 //Maximum angle in degree upto which servo can rotate
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static void mcpwm_example_gpio_initialize()
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{
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printf("initializing mcpwm servo control gpio......\n");
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mcpwm_gpio_init(MCPWM_UNIT_0, MCPWM0A, 18); //Set GPIO 18 as PWM0A, to which servo is connected
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}
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/**
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* @brief Use this function to calcute pulse width for per degree rotation
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*
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* @param degree_of_rotation the angle in degree to which servo has to rotate
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*
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* @return
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* - calculated pulse width
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*/
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static uint32_t servo_per_degree_init(uint32_t degree_of_rotation)
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{
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uint32_t cal_pulsewidth = 0;
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cal_pulsewidth = (SERVO_MIN_PULSEWIDTH + (((SERVO_MAX_PULSEWIDTH - SERVO_MIN_PULSEWIDTH) * (degree_of_rotation)) / (SERVO_MAX_DEGREE)));
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return cal_pulsewidth;
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}
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/**
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* @brief directly set servo motor to a particular angle
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*/
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static void servo_set_angle(uint32_t angle_of_rotation)
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{
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uint32_t angle_t;
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angle_t = servo_per_degree_init(angle_of_rotation);
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mcpwm_set_duty_in_us(MCPWM_UNIT_0, MCPWM_TIMER_0, MCPWM_OPR_A, angle_t);
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}
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/**
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* @brief Configure MCPWM module
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*/
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void mcpwm_example_servo_control(void *arg)
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{
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uint32_t angle, count;
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//1. mcpwm gpio initialization
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mcpwm_example_gpio_initialize();
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//2. initial mcpwm configuration
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printf("Configuring Initial Parameters of mcpwm......\n");
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mcpwm_config_t pwm_config;
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pwm_config.frequency = 50; //frequency = 50Hz, i.e. for every servo motor time period should be 20ms
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pwm_config.cmpr_a = 0; //duty cycle of PWMxA = 0
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pwm_config.cmpr_b = 0; //duty cycle of PWMxb = 0
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pwm_config.counter_mode = MCPWM_UP_COUNTER;
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pwm_config.duty_mode = MCPWM_DUTY_MODE_0;
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mcpwm_init(MCPWM_UNIT_0, MCPWM_TIMER_0, &pwm_config); //Configure PWM0A & PWM0B with above settings
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while (1) {
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for (count = 0; count < SERVO_MAX_DEGREE; count++) {
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printf("Angle of rotation: %d\n", count);
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angle = servo_per_degree_init(count);
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printf("pulse width: %dus\n", angle);
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mcpwm_set_duty_in_us(MCPWM_UNIT_0, MCPWM_TIMER_0, MCPWM_OPR_A, angle);
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vTaskDelay(10); //Add delay, since it takes time for servo to rotate, generally 100ms/60degree rotation at 5V
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}
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}
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}
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void app_main()
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{
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printf("Testing servo motor.......\n");
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xTaskCreate(mcpwm_example_servo_control, "mcpwm_example_servo_control", 4096, NULL, 5, NULL);
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} |