Skip to main content

pwm-led-fade

Fade an LED on PWM channel E1M_PWM0 from 0 % → 100 % → 0 %. The canonical open / set-duty / close pattern for <alp/pwm.h>.

Source: examples/pwm-led-fade/.

board.yaml​

schema_version: 2

som:
  sku: E1M-AEN701

carrier:
  name: E1M-EVK

cores:
  m55_hp:
    os: zephyr
    app: ./src
    peripherals: [pwm]

diagnostics:
  log_level: info

Source (abbreviated)​

#include <alp/pwm.h>
#include <alp/e1m_pinout.h>

int main(void) {
    alp_pwm_t *pwm = alp_pwm_open(&(alp_pwm_config_t){
        .channel_id = E1M_PWM0,
    });
    if (pwm == NULL) {
        printk("[pwm] open failed: err=%d\n", (int)alp_last_error());
        return -1;
    }

    const uint32_t period_ns = 1000000u;     /* 1 kHz */
    for (uint32_t duty = 0; duty <= period_ns; duty += period_ns / 20u) {
        alp_pwm_set(pwm, period_ns, duty);
        k_msleep(50);
    }
    alp_pwm_close(pwm);
    return 0;
}

Build​

# native_sim
west alp-build -b native_sim/native/64 alp-sdk/examples/pwm-led-fade
west build -d build -t run

# Real silicon (E1M EVK + AEN)
west alp-build -b alp_e1m_evk_aen alp-sdk/examples/pwm-led-fade
west flash

The example's boards/alp_e1m_evk_aen.overlay points alp-pwm0 at the EVK's user LED.

See also​

Questions about this page? Discuss in Community Forum