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/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file Sample app to demonstrate PWM.
*
* This app uses PWM[0].
*/
#include <zephyr.h>
#include <misc/printk.h>
#include <device.h>
#include <pwm.h>
#if defined(CONFIG_SOC_STM32F401XE) || defined(CONFIG_SOC_STM32L476XX)
#define PWM_DRIVER CONFIG_PWM_STM32_2_DEV_NAME
#define PWM_CHANNEL 1
#elif CONFIG_SOC_STM32F103XB
#define PWM_DRIVER CONFIG_PWM_STM32_1_DEV_NAME
#define PWM_CHANNEL 1
#elif defined(CONFIG_SOC_QUARK_SE_C1000) || defined(CONFIG_SOC_QUARK_D2000)
#define PWM_DRIVER CONFIG_PWM_QMSI_DEV_NAME
#define PWM_CHANNEL 0
#else
#error "Choose supported PWM driver"
#endif
/*
* 50 is flicker fusion threshold. Modulated light will be perceived
* as steady by our eyes when blinking rate is at least 50.
*/
#define PERIOD (USEC_PER_SEC / 50)
/* in micro second */
#define FADESTEP 2000
void main(void)
{
struct device *pwm_dev;
uint32_t pulse_width = 0;
uint8_t dir = 0;
printk("PWM demo app-fade LED\n");
pwm_dev = device_get_binding(PWM_DRIVER);
if (!pwm_dev) {
printk("Cannot find %s!\n", PWM_DRIVER);
return;
}
while (1) {
if (pwm_pin_set_usec(pwm_dev, PWM_CHANNEL,
PERIOD, pulse_width)) {
printk("pwm pin set fails\n");
return;
}
if (dir) {
if (pulse_width < FADESTEP) {
dir = 0;
pulse_width = 0;
} else {
pulse_width -= FADESTEP;
}
} else {
pulse_width += FADESTEP;
if (pulse_width >= PERIOD) {
dir = 1;
pulse_width = PERIOD;
}
}
k_sleep(MSEC_PER_SEC);
}
}
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