要设置ATSAMC21的PWM占空比为99%,可以使用Atmel START配置工具和ASF(Atmel Software Framework)来实现。以下是一个示例代码,通过使用ASF库函数来设置PWM占空比为99%。
#include
#define PWM_MODULE TC3
#define PWM_CHANNEL 0
#define PWM_FREQUENCY 10000
#define PWM_DUTY_CYCLE 99
int main(void)
{
/* 初始化系统 */
system_init();
/* 配置PWM引脚 */
struct system_pinmux_config pinmux_config = {
.mux_position = MUX_PA18E_TC3_WO0,
.direction = SYSTEM_PINMUX_PIN_DIR_OUTPUT,
.input_pull = SYSTEM_PINMUX_PIN_PULL_NONE,
.powersave = false
};
system_pinmux_pin_set_config(PIN_PA18E_TC3_WO0, &pinmux_config);
/* 配置PWM模块 */
struct tc_config config_tc;
tc_get_config_defaults(&config_tc);
config_tc.counter_size = TC_COUNTER_SIZE_16BIT;
config_tc.counter_16_bit.compare_capture_channel[0] = PWM_DUTY_CYCLE * (65535 / 100);
config_tc.counter_16_bit.wave_generation = TC_WAVE_GENERATION_MATCH_FREQ;
config_tc.counter_16_bit.waveform_invert_output = TC_WAVEFORM_INVERT_OUTPUT_CHANNEL_0;
config_tc.counter_16_bit.pwm_channel[0].enabled = true;
config_tc.counter_16_bit.pwm_channel[0].pin_out = PIN_PA18E_TC3_WO0;
config_tc.counter_16_bit.pwm_channel[0].pin_mux = PINMUX_PA18E_TC3_WO0;
tc_init(&PWM_MODULE, PWM_CHANNEL, &config_tc);
/* 启动PWM */
tc_enable(&PWM_MODULE);
while (1) {
/* 无限循环 */
}
}
请注意,使用此示例代码需要先配置Atmel START工具和ASF库。您可以根据您的具体需求进行修改和适配。