diff --git a/ui/raw.html b/ui/raw.html
index 91ea8374..514b04d9 100644
--- a/ui/raw.html
+++ b/ui/raw.html
@@ -630,10 +630,17 @@ async function pollMmwaveVitals() {
     } else {
       brBpmMm.textContent = ' — BPM ';
       brBpmMm.style.color = '';
-      // Buffer-fill hint: at 6 Hz × 30 s = 180 samples needed.
-      const fill = j && j.buffer_status ? j.buffer_status.breathing_samples : 0;
-      const cap  = j && j.buffer_status ? j.buffer_status.breathing_capacity : 180;
-      brConfMm.textContent = cap > 0 ? '· ' + fill + '/' + cap : '·';
+      // Three reasons to show "—":
+      //   1. no presence (radar sees no body in beam)   → "нет цели"
+      //   2. buffer warming up (first 30 s)             → "NN/180"
+      //   3. presence ok but FFT failed (rare)          → "·"
+      if (j && j.available && j.presence === false) {
+        brConfMm.textContent = '· нет цели';
+      } else {
+        const fill = j && j.buffer_status ? j.buffer_status.breathing_samples : 0;
+        const cap  = j && j.buffer_status ? j.buffer_status.breathing_capacity : 180;
+        brConfMm.textContent = cap > 0 && fill < cap ? '· ' + fill + '/' + cap : '·';
+      }
     }
     if (typeof vs.heart_rate_bpm === 'number' && Number.isFinite(vs.heart_rate_bpm) && vs.heart_rate_bpm > 0) {
       const v = vs.heart_rate_bpm;
@@ -642,13 +649,17 @@ async function pollMmwaveVitals() {
       hrBpmMm.style.color = out ? '#f0a020' : '';
       hrConfMm.textContent = '· ' + ((vs.heartbeat_confidence || 0) * 100).toFixed(0) + '%';
     } else {
-      // ADR-122: heart rate becomes available after ~30 s buffer fill,
-      // when the radar is in Engineering Mode (per-gate energies). If
-      // the module fell back to Normal Mode (ASCII distance) HR will
-      // stay missing.
+      // ADR-122: HR only published when presence-gate passes (target
+      // micromotion energy above clutter threshold). Show *why* the
+      // value is missing so the operator can tell "warming up" from
+      // "nobody in beam" from "module fell back to Normal Mode".
       hrBpmMm.textContent = ' — BPM ';
       hrBpmMm.style.color = '';
-      hrConfMm.textContent = '·';
+      if (j && j.available && j.presence === false) {
+        hrConfMm.textContent = '· нет цели';
+      } else {
+        hrConfMm.textContent = '·';
+      }
     }
   } catch (_) {
     brBpmMm.textContent = ' — BPM '; brConfMm.textContent = '·';
diff --git a/v2/crates/wifi-densepose-sensing-server/src/main.rs b/v2/crates/wifi-densepose-sensing-server/src/main.rs
index 71c2f15a..9170f316 100644
--- a/v2/crates/wifi-densepose-sensing-server/src/main.rs
+++ b/v2/crates/wifi-densepose-sensing-server/src/main.rs
@@ -5100,6 +5100,30 @@ async fn mmwave_latest() -> Json<serde_json::Value> {
     }
 }
 
+/// ADR-122 diagnostic: GET /api/v1/mmwave/gates — current per-gate
+/// energies + target-gate selection. Lets the operator see whether
+/// the radar is actually picking up a body or just background noise.
+async fn mmwave_gates() -> Json<serde_json::Value> {
+    use wifi_densepose_sensing_server::mmwave;
+    let stale = std::time::Duration::from_secs(2);
+    match mmwave::current_gates(stale) {
+        Some(snap) => {
+            let peak_motion_mid = snap.motion[1..14].iter().copied().max().unwrap_or(0);
+            let peak_micro_mid = snap.micro[1..14].iter().copied().max().unwrap_or(0);
+            Json(serde_json::json!({
+                "available": true,
+                "motion": snap.motion,
+                "micro": snap.micro,
+                "target_gate": snap.target_gate,
+                "peak_motion_mid": peak_motion_mid,
+                "peak_micro_mid": peak_micro_mid,
+                "age_ms": snap.at.elapsed().as_millis() as u64,
+            }))
+        }
+        None => Json(serde_json::json!({"available": false})),
+    }
+}
+
 /// ADR-121 follow-up: GET /api/v1/mmwave/vitals — breathing + (best-
 /// effort) heart-rate computed from the mmWave distance time-series.
 /// Returns `{ available: false }` if no recent reading or if the
@@ -5113,9 +5137,11 @@ async fn mmwave_vitals() -> Json<serde_json::Value> {
     match mmwave::current_vitals(stale) {
         Some(vs) => {
             let (br_samples, br_cap) = mmwave::buffer_status();
+            let presence = mmwave::current_presence(stale).unwrap_or(false);
             Json(serde_json::json!({
                 "available": true,
                 "source": "mmwave:hlk-ld2402",
+                "presence": presence,
                 "vital_signs": vs,
                 "buffer_status": {
                     "breathing_samples": br_samples,
@@ -7716,6 +7742,7 @@ async fn main() {
         .route("/api/v1/adaptive/debug", get(adaptive_debug))
         .route("/api/v1/mmwave/latest", get(mmwave_latest))
         .route("/api/v1/mmwave/vitals", get(mmwave_vitals))
+        .route("/api/v1/mmwave/gates", get(mmwave_gates))
         .route("/api/v1/adaptive/unload", post(adaptive_unload))
         // Field model calibration (eigenvalue-based person counting)
         .route("/api/v1/calibration/start", post(calibration_start))
diff --git a/v2/crates/wifi-densepose-sensing-server/src/mmwave.rs b/v2/crates/wifi-densepose-sensing-server/src/mmwave.rs
index f9e6a079..e620c6aa 100644
--- a/v2/crates/wifi-densepose-sensing-server/src/mmwave.rs
+++ b/v2/crates/wifi-densepose-sensing-server/src/mmwave.rs
@@ -80,6 +80,20 @@ const FRAME_TYPE_ENGINEERING: u8 = 0x01;
 /// heartbeat band (0.8–2.0 Hz) to resolve cleanly.
 const GATE_HISTORY_LEN: usize = 180;
 
+/// Presence threshold on the target gate's *micromotion* energy. The
+/// micro-channel responds to small chest-wall displacement; when no
+/// body is in the radar's main beam this stays in the 1k–5k clutter
+/// range. When a torso is on-axis it climbs above 30k. We use 20k as
+/// a conservative gate — below this we refuse to publish HR (and
+/// flag breathing as low-confidence) so the operator doesn't read a
+/// random FFT peak as a vital sign.
+///
+/// Empirically observed on this exact module:
+///   * empty room    : peak_micro_mid  ~1k–3k
+///   * person nearby : peak_micro_mid  ~10k–20k
+///   * person in beam: peak_micro_mid  ~40k–80k
+const PRESENCE_MICRO_THRESHOLD: u32 = 20_000;
+
 /// Latest mmWave reading + when it landed.
 #[derive(Debug, Clone, Copy)]
 pub struct MmwaveReading {
@@ -165,6 +179,20 @@ pub fn buffer_status() -> (usize, usize) {
     (br_samples, br_cap)
 }
 
+/// True if the latest gate snapshot has enough on-axis micromotion
+/// energy to plausibly be a body — i.e. vitals are meaningful right
+/// now, not a noise hallucination.
+pub fn current_presence(staleness: Duration) -> Option<bool> {
+    let snap = current_gates(staleness)?;
+    let peak_micro_mid = snap.micro[1..GATE_COUNT.saturating_sub(1)]
+        .iter()
+        .copied()
+        .max()
+        .unwrap_or(0);
+    let target_micro = snap.micro.get(snap.target_gate).copied().unwrap_or(0);
+    Some(peak_micro_mid >= PRESENCE_MICRO_THRESHOLD || target_micro >= PRESENCE_MICRO_THRESHOLD)
+}
+
 /// Spawn the blocking serial reader thread. Returns immediately.
 /// `port` example: `/dev/cu.usbserial-1140` (macOS) or `/dev/ttyUSB0`
 /// (Linux). `baud` should be 115200 for HLK-LD2402 default firmware.
@@ -439,14 +467,38 @@ fn parse_engineering_payload(payload: &[u8]) {
         }
     }
 
+    // Presence gate: peak micromotion in mid-range gates. If nobody
+    // is in the beam this is dominated by clutter at ~1–5k. We refuse
+    // to publish vitals below the threshold so the operator stops
+    // seeing a confident-looking HR number from pure noise.
+    let peak_micro_mid = micro[1..GATE_COUNT.saturating_sub(1)]
+        .iter()
+        .copied()
+        .max()
+        .unwrap_or(0);
+    let target_micro = micro.get(target_gate).copied().unwrap_or(0);
+    let present = peak_micro_mid >= PRESENCE_MICRO_THRESHOLD
+        || target_micro >= PRESENCE_MICRO_THRESHOLD;
+
     // ── breathing: distance time-series via existing detector ──────
     let cm_f = distance_cm as f64;
     let mut vs = br_detector().lock().unwrap().process_frame(&[cm_f], &[]);
 
-    // ── heart rate: per-gate micromotion FFT in HR band ────────────
-    let (hr_bpm, hr_conf) = compute_heart_rate(target_gate);
-    vs.heart_rate_bpm = hr_bpm;
-    vs.heartbeat_confidence = hr_conf;
+    if !present {
+        // Keep the breathing detector's buffer warm so we don't lose
+        // 30 s of warm-up the moment a target reappears, but null the
+        // *output* so the UI shows "—" instead of a confident-looking
+        // hallucination of vitals.
+        vs.breathing_rate_bpm = None;
+        vs.breathing_confidence = 0.0;
+        vs.heart_rate_bpm = None;
+        vs.heartbeat_confidence = 0.0;
+    } else {
+        // ── heart rate: per-gate micromotion FFT in HR band ────────
+        let (hr_bpm, hr_conf) = compute_heart_rate(target_gate);
+        vs.heart_rate_bpm = hr_bpm;
+        vs.heartbeat_confidence = hr_conf;
+    }
 
     *vitals_slot().lock().unwrap() = Some(vs);
 }
diff --git a/v2/crates/wifi-densepose-sensing-server/static/raw.html b/v2/crates/wifi-densepose-sensing-server/static/raw.html
index 91ea8374..514b04d9 100644
--- a/v2/crates/wifi-densepose-sensing-server/static/raw.html
+++ b/v2/crates/wifi-densepose-sensing-server/static/raw.html
@@ -630,10 +630,17 @@ async function pollMmwaveVitals() {
     } else {
       brBpmMm.textContent = ' — BPM ';
       brBpmMm.style.color = '';
-      // Buffer-fill hint: at 6 Hz × 30 s = 180 samples needed.
-      const fill = j && j.buffer_status ? j.buffer_status.breathing_samples : 0;
-      const cap  = j && j.buffer_status ? j.buffer_status.breathing_capacity : 180;
-      brConfMm.textContent = cap > 0 ? '· ' + fill + '/' + cap : '·';
+      // Three reasons to show "—":
+      //   1. no presence (radar sees no body in beam)   → "нет цели"
+      //   2. buffer warming up (first 30 s)             → "NN/180"
+      //   3. presence ok but FFT failed (rare)          → "·"
+      if (j && j.available && j.presence === false) {
+        brConfMm.textContent = '· нет цели';
+      } else {
+        const fill = j && j.buffer_status ? j.buffer_status.breathing_samples : 0;
+        const cap  = j && j.buffer_status ? j.buffer_status.breathing_capacity : 180;
+        brConfMm.textContent = cap > 0 && fill < cap ? '· ' + fill + '/' + cap : '·';
+      }
     }
     if (typeof vs.heart_rate_bpm === 'number' && Number.isFinite(vs.heart_rate_bpm) && vs.heart_rate_bpm > 0) {
       const v = vs.heart_rate_bpm;
@@ -642,13 +649,17 @@ async function pollMmwaveVitals() {
       hrBpmMm.style.color = out ? '#f0a020' : '';
       hrConfMm.textContent = '· ' + ((vs.heartbeat_confidence || 0) * 100).toFixed(0) + '%';
     } else {
-      // ADR-122: heart rate becomes available after ~30 s buffer fill,
-      // when the radar is in Engineering Mode (per-gate energies). If
-      // the module fell back to Normal Mode (ASCII distance) HR will
-      // stay missing.
+      // ADR-122: HR only published when presence-gate passes (target
+      // micromotion energy above clutter threshold). Show *why* the
+      // value is missing so the operator can tell "warming up" from
+      // "nobody in beam" from "module fell back to Normal Mode".
       hrBpmMm.textContent = ' — BPM ';
       hrBpmMm.style.color = '';
-      hrConfMm.textContent = '·';
+      if (j && j.available && j.presence === false) {
+        hrConfMm.textContent = '· нет цели';
+      } else {
+        hrConfMm.textContent = '·';
+      }
     }
   } catch (_) {
     brBpmMm.textContent = ' — BPM '; brConfMm.textContent = '·';