| /* |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * @file Sample app to demonstrate PWM. |
| * |
| * This app uses PWM[0]. |
| */ |
| |
| #include <zephyr.h> |
| #include <misc/printk.h> |
| #include <device.h> |
| #include <pwm.h> |
| |
| /* |
| * 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 STEPSIZE 2000 |
| |
| static int write_pin(struct device *pwm_dev, uint32_t pwm_pin, |
| uint32_t pulse_width) |
| { |
| return pwm_pin_set_usec(pwm_dev, pwm_pin, PERIOD, pulse_width); |
| } |
| |
| void main(void) |
| { |
| struct device *pwm_dev; |
| uint32_t pulse_width0, pulse_width1, pulse_width2; |
| |
| printk("PWM demo app-RGB LED\n"); |
| |
| pwm_dev = device_get_binding("PWM_0"); |
| if (!pwm_dev) { |
| printk("Cannot find PWM_0!\n"); |
| return; |
| } |
| |
| while (1) { |
| for (pulse_width0 = 0; pulse_width0 <= PERIOD; |
| pulse_width0 += STEPSIZE) { |
| if (write_pin(pwm_dev, 0, pulse_width0) != 0) { |
| printk("pin 0 write fails!\n"); |
| return; |
| } |
| |
| for (pulse_width1 = 0; pulse_width1 <= PERIOD; |
| pulse_width1 += STEPSIZE) { |
| if (write_pin(pwm_dev, 1, pulse_width1) != 0) { |
| printk("pin 1 write fails!\n"); |
| return; |
| } |
| |
| for (pulse_width2 = 0; pulse_width2 <= PERIOD; |
| pulse_width2 += STEPSIZE) { |
| if (write_pin(pwm_dev, 2, pulse_width2) |
| != 0) { |
| printk("pin 2 write fails!\n"); |
| return; |
| } |
| k_sleep(MSEC_PER_SEC); |
| } |
| } |
| } |
| } |
| } |