- #include "bflb_gpio.h" //gpio头文件
- #include "board.h" //开发板头文件，包装的库
- #include "bflb_mtimer.h" //mtimer定时器头文件
- #include "bflb_pwm_v2.h" //pwm_v2头文件
- #include "bflb_clock.h" //系统时钟头文件
- struct bflb_device_s *gpio;
- struct bflb_device_s *pwm; //创建LHAL外设库结构体，名称为pwm
- void gpio_init() //编写一个选择pwm输出的gpio口初始化函数
- {
- struct bflb_device_s *gpio;
- gpio = bflb_device_get_by_name("gpio");
- bflb_gpio_init(gpio, GPIO_PIN_12, GPIO_FUNC_PWM0 | GPIO_ALTERNATE | GPIO_PULLUP | GPIO_SMT_EN | GPIO_DRV_1);
- //bflb_gpio_init(gpio, GPIO_PIN_12, GPIO_OUTPUT | GPIO_PULLUP | GPIO_SMT_EN | GPIO_DRV_0);
- bflb_gpio_init(gpio, GPIO_PIN_1, GPIO_INPUT | GPIO_PULLUP | GPIO_SMT_EN | GPIO_DRV_0);
- //选择IO0作为pwm输出，
- }
- int main(void)
- {
- int i;
- board_init();
- printf("gpio output\r\n");
- gpio_init();
- pwm = bflb_device_get_by_name("pwm_v2_0"); //给外设接口赋名pwm_v2_0
- /* period = .XCLK / .clk_div / .period = 40MHz / 40 / 1000 = 1KHz */
- struct bflb_pwm_v2_config_s cfg = {
- .clk_source = BFLB_SYSTEM_XCLK,
- .clk_div = 40,
- .period = 1000,
- }; //设置PWM的频率，选择时钟，分频，和周期。根据上面的公式算出最终的频率。
-
- /*初始化PWM输出*/
- bflb_pwm_v2_init(pwm, &cfg);
- bflb_pwm_v2_start(pwm); //将设置好的频率开启pwm输出
- while (1) {
- //蓝灯呼吸亮灭
- bflb_pwm_v2_channel_positive_start(pwm, PWM_CH0); //那么问题来了，如何知道IO口对应的PWM通道，后面会解答，IO0是通道0
- for(i=150;i>0;i--){
- bflb_pwm_v2_channel_set_threshold(pwm, PWM_CH0, i, 150); //改变占空比，变量i会不断变化
- bflb_mtimer_delay_ms(10);
- }
- for(i=1;i<150;i++){
- bflb_pwm_v2_channel_set_threshold(pwm, PWM_CH0, i, 150);
- bflb_mtimer_delay_ms(10);
- }
-
- bflb_pwm_v2_channel_positive_stop(pwm, PWM_CH0);
- }
- }
|
