feel
warm.
connect.

/* OMPHONE FIRMWARE v1.0 — nRF52832
   Three modes: meditation · proximity · sync     */

#define BEAT_INTERVAL_MEDITATION  7000   // 7s — meditation
#define BEAT_INTERVAL_MIN          800   // fastest — very close
#define LUB_DURATION                70   // first thump ms
#define LUB_DUB_GAP               180   // gap between lub + dub
#define NTC_ADC_THRESHOLD         680   // ~45°C safety cutoff

static void heartbeat_beat(void) {
    /* Scale pulse to proximity */
    uint32_t pulse = (rssi >= RSSI_CLOSE) ? MOTOR_STRONG : MOTOR_SOFT;

    motor_pulse(pulse);        // LUB
    nrf_delay_ms(LUB_DUB_GAP);
    motor_pulse(pulse);        // DUB
}

static void heartbeat_timer_handler(void *p) {
    heartbeat_beat();
    heater_set_duty(proximity_to_heat(m_nearest_rssi));

    uint32_t next = map_range(m_nearest_rssi,
        RSSI_FAR, RSSI_CLOSE,
        BEAT_INTERVAL_MAX, BEAT_INTERVAL_MIN);

    app_timer_start(m_heartbeat_timer,
        APP_TIMER_TICKS(next), NULL);
}