| /* |
| * 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 <sys/printk.h> |
| #include <device.h> |
| #include <drivers/pwm.h> |
| |
| #if defined(DT_ALIAS_PWM_LED0_PWMS_CONTROLLER) && defined(DT_ALIAS_PWM_LED0_PWMS_CHANNEL) |
| /* get the defines from dt (based on alias 'pwm-led0') */ |
| #define PWM_DRIVER DT_ALIAS_PWM_LED0_PWMS_CONTROLLER |
| #define PWM_CHANNEL DT_ALIAS_PWM_LED0_PWMS_CHANNEL |
| #else |
| #error "Choose supported PWM driver" |
| #endif |
| |
| void main(void) |
| { |
| struct device *pwm_dev; |
| u32_t period, min_period, max_period; |
| u64_t cycles; |
| u8_t dir = 0U; |
| |
| printk("PWM demo app-blink LED\n"); |
| |
| pwm_dev = device_get_binding(PWM_DRIVER); |
| if (!pwm_dev) { |
| printk("Cannot find %s!\n", PWM_DRIVER); |
| return; |
| } |
| |
| /* Adjust max_period depending pwm capabilities */ |
| pwm_get_cycles_per_sec(pwm_dev, PWM_CHANNEL, &cycles); |
| /* in very worst case, PWM has a 8 bit resolution and count up to 256 */ |
| period = max_period = 256 * USEC_PER_SEC / cycles; |
| min_period = max_period / 64; |
| |
| while (1) { |
| if (pwm_pin_set_usec(pwm_dev, PWM_CHANNEL, |
| period, period / 2U)) { |
| printk("pwm pin set fails\n"); |
| return; |
| } |
| |
| if (dir) { |
| period *= 2U; |
| |
| if (period > max_period) { |
| dir = 0U; |
| period = max_period; |
| } |
| } else { |
| period /= 2U; |
| |
| if (period < min_period) { |
| dir = 1U; |
| period = min_period; |
| } |
| } |
| |
| k_sleep(MSEC_PER_SEC * 4U); |
| } |
| } |