Function dsp_get

src/features.rs:585–651

(feature: &Feature)

// ─── DSP Getter/Setter (0x96 family via 0x11/0x12) ──────────────────────────

fn dsp_get(feature: &Feature) -> f32 {
    let (family, feature_id) = feature
        .id
        .dsp_address()
        .expect("dsp_get called on non-DSP feature");

    debug!(
        "Querying DSP feature: {} (0x{:02x}:0x{:02x})",
        feature.id, family, feature_id
    );

    let mut payload = [0u8; 65];
    payload[1] = 0x5a;
    payload[2] = 0x11;
    payload[3] = 0x03;
    payload[4] = 0x01;
    payload[5] = family;
    payload[6] = feature_id;

    DEVICE_CONNECTION
        .get()
        .expect("Device Connection must be initialized")
        .lock()
        .unwrap()
        .write(&payload)
        .expect("Failed to send Query to Device");

    for attempt in 0..MAX_READ_ATTEMPTS {
        let Some(response) = read_packet() else {
            error!(
                "No response on attempt {}/{} for {}",
                attempt + 1,
                MAX_READ_ATTEMPTS,
                feature.id
            );
            continue;
        };

        // expected: 5a 11 08 01 00 [family] [id] [f32 LE × 4]
        if response[0] == 0x5a
            && response[1] == 0x11
            && response[5] == family
            && response[6] == feature_id
        {
            let value = f32::from_le_bytes(
                response[7..11]
                    .try_into()
                    .expect("Failed to parse f32 from response bytes"),
            );
            debug!("Read {} = {}", feature.id, value);
            *feature.value.lock().unwrap() = value;
            return value;
        }

        debug!(
            "Discarded stale packet on attempt {}: {:02x?}",
            attempt + 1,
            &response[..12]