e8224c3a08
Replace device_get_binding with DEVICE_DT_GET for getting access to the pwm controller device. Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
77 lines
1.4 KiB
C
77 lines
1.4 KiB
C
/*
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* Copyright (c) 2016 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @file Sample app to demonstrate PWM-based servomotor control
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*/
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#include <zephyr.h>
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#include <sys/printk.h>
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#include <device.h>
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#include <drivers/pwm.h>
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#define PWM_NODE DT_ALIAS(pwm_servo)
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#if !DT_NODE_HAS_STATUS(PWM_NODE, okay)
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#error "Unsupported board: pwm-servo devicetree alias is not defined or enabled"
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#endif
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/*
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* Unlike pulse width, the PWM period is not a critical parameter for
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* motor control. 20 ms is commonly used.
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*/
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#define PERIOD_USEC (20U * USEC_PER_MSEC)
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#define STEP_USEC 100
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#define MIN_PULSE_USEC 700
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#define MAX_PULSE_USEC 2300
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enum direction {
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DOWN,
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UP,
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};
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void main(void)
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{
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const struct device *pwm;
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uint32_t pulse_width = MIN_PULSE_USEC;
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enum direction dir = UP;
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int ret;
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printk("Servomotor control\n");
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pwm = DEVICE_DT_GET(PWM_NODE);
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if (!device_is_ready(pwm)) {
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printk("Error: PWM device %s is not ready\n", pwm->name);
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return;
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}
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while (1) {
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ret = pwm_pin_set_usec(pwm, 0, PERIOD_USEC, pulse_width, 0);
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if (ret < 0) {
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printk("Error %d: failed to set pulse width\n", ret);
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return;
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}
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if (dir == DOWN) {
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if (pulse_width <= MIN_PULSE_USEC) {
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dir = UP;
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pulse_width = MIN_PULSE_USEC;
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} else {
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pulse_width -= STEP_USEC;
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}
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} else {
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pulse_width += STEP_USEC;
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if (pulse_width >= MAX_PULSE_USEC) {
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dir = DOWN;
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pulse_width = MAX_PULSE_USEC;
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}
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}
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k_sleep(K_SECONDS(1));
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}
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}
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