diff --git a/NOISE_FLOOR_USAGE.md b/NOISE_FLOOR_USAGE.md
new file mode 100644
index 0000000..3934c31
--- /dev/null
+++ b/NOISE_FLOOR_USAGE.md
@@ -0,0 +1,153 @@
+# Noise Floor Measurement - Usage Guide
+
+## Overview
+The noise floor measurement capability has been added to provide real-time RF environment monitoring.
+
+## Implementation
+
+### 1. Radio Wrapper (pyMC_core)
+Added `get_noise_floor()` method to `SX1262Radio` class:
+
+```python
+def get_noise_floor(self) -> Optional[float]:
+ """
+ Get current noise floor (instantaneous RSSI) in dBm.
+ Returns None if radio is not initialized or if reading fails.
+ """
+```
+
+### 2. Repeater Engine (pyMC_Repeater)
+Added `get_noise_floor()` method to `RepeaterHandler` class:
+
+```python
+def get_noise_floor(self) -> Optional[float]:
+ """
+ Get the current noise floor (instantaneous RSSI) from the radio in dBm.
+ Returns None if radio is not available or reading fails.
+ """
+```
+
+The noise floor is automatically included in the stats dictionary returned by `get_stats()`:
+
+```python
+stats = handler.get_stats()
+noise_floor = stats.get('noise_floor_dbm') # Returns float or None
+```
+
+## Usage Examples
+
+### Example 1: Get Noise Floor Directly
+```python
+# From the repeater engine
+handler = RepeaterHandler(config, dispatcher, local_hash)
+noise_floor_dbm = handler.get_noise_floor()
+
+if noise_floor_dbm is not None:
+ print(f"Current noise floor: {noise_floor_dbm:.1f} dBm")
+else:
+ print("Noise floor not available")
+```
+
+### Example 2: Access via Stats
+```python
+# Get all stats including noise floor
+stats = handler.get_stats()
+noise_floor = stats.get('noise_floor_dbm')
+
+if noise_floor is not None:
+ print(f"RF Environment: {noise_floor:.1f} dBm")
+```
+
+### Example 3: Monitor RF Environment
+```python
+import asyncio
+
+async def monitor_rf_environment(handler, interval=5.0):
+ """Monitor noise floor every N seconds"""
+ while True:
+ noise_floor = handler.get_noise_floor()
+ if noise_floor is not None:
+ if noise_floor > -100:
+ print(f"⚠️ High RF noise: {noise_floor:.1f} dBm")
+ else:
+ print(f"✓ Normal RF environment: {noise_floor:.1f} dBm")
+ await asyncio.sleep(interval)
+```
+
+### Example 4: Channel Assessment Before TX
+```python
+async def should_transmit(handler, threshold_dbm=-110):
+ """
+ Check if channel is clear before transmitting.
+ Returns True if noise floor is below threshold (channel clear).
+ """
+ noise_floor = handler.get_noise_floor()
+
+ if noise_floor is None:
+ # Can't determine, allow transmission
+ return True
+
+ if noise_floor > threshold_dbm:
+ # Channel busy - high noise
+ print(f"Channel busy: {noise_floor:.1f} dBm > {threshold_dbm} dBm")
+ return False
+
+ # Channel clear
+ return True
+```
+
+## Integration with Web Dashboard
+
+The noise floor is automatically available in the `/api/stats` endpoint:
+
+```javascript
+// JavaScript example for web dashboard
+fetch('/api/stats')
+ .then(response => response.json())
+ .then(data => {
+ const noiseFloor = data.noise_floor_dbm;
+ if (noiseFloor !== null) {
+ updateNoiseFloorDisplay(noiseFloor);
+ }
+ });
+```
+
+## Interpretation
+
+### Typical Values
+- **-120 to -110 dBm**: Very quiet RF environment (rural, low interference)
+- **-110 to -100 dBm**: Normal RF environment (typical conditions)
+- **-100 to -90 dBm**: Moderate RF noise (urban, some interference)
+- **-90 dBm and above**: High RF noise (congested environment, potential issues)
+
+### Use Cases
+1. **Collision Avoidance**: Check noise floor before transmitting to detect if another station is already transmitting
+2. **RF Environment Monitoring**: Track RF noise levels over time for site assessment
+3. **Adaptive Transmission**: Adjust TX timing or power based on channel conditions
+4. **Debugging**: Identify sources of interference or poor reception
+
+## Technical Details
+
+### Calculation
+The noise floor is calculated from the SX1262's instantaneous RSSI register:
+```python
+raw_rssi = self.lora.getRssiInst()
+noise_floor_dbm = -(float(raw_rssi) / 2)
+```
+
+### Update Rate
+The noise floor is read on-demand when `get_noise_floor()` is called. There is no caching - each call queries the radio hardware directly.
+
+### Error Handling
+- Returns `None` if radio is not initialized
+- Returns `None` if read fails (hardware error)
+- Logs debug message on error (doesn't raise exceptions)
+
+## Future Enhancements
+
+Potential future improvements:
+1. **Averaging**: Average noise floor over multiple samples for stability
+2. **History**: Track noise floor history for trend analysis
+3. **Thresholds**: Configurable thresholds for channel busy detection
+4. **Carrier Sense**: Automatic carrier sense before each transmission
+5. **Spectral Analysis**: Extended to include RSSI across multiple channels
diff --git a/repeater/engine.py b/repeater/engine.py
index bdbeeb0..d6252dc 100644
--- a/repeater/engine.py
+++ b/repeater/engine.py
@@ -563,6 +563,20 @@ class RepeaterHandler(BaseHandler):
except Exception as e:
logger.error(f"Error sending periodic advert: {e}", exc_info=True)
+ def get_noise_floor(self) -> Optional[float]:
+ """
+ Get the current noise floor (instantaneous RSSI) from the radio in dBm.
+ Returns None if radio is not available or reading fails.
+ """
+ try:
+ radio = self.dispatcher.radio if self.dispatcher else None
+ if radio and hasattr(radio, 'get_noise_floor'):
+ return radio.get_noise_floor()
+ return None
+ except Exception as e:
+ logger.debug(f"Failed to get noise floor: {e}")
+ return None
+
def get_stats(self) -> dict:
uptime_seconds = time.time() - self.start_time
@@ -581,6 +595,9 @@ class RepeaterHandler(BaseHandler):
rx_per_hour = len(packets_last_hour)
forwarded_per_hour = sum(1 for p in packets_last_hour if p.get("transmitted", False))
+ # Get current noise floor from radio
+ noise_floor_dbm = self.get_noise_floor()
+
stats = {
"local_hash": f"0x{self.local_hash: 02x}",
"duplicate_cache_size": len(self.seen_packets),
@@ -593,6 +610,7 @@ class RepeaterHandler(BaseHandler):
"recent_packets": self.recent_packets,
"neighbors": self.neighbors,
"uptime_seconds": uptime_seconds,
+ "noise_floor_dbm": noise_floor_dbm,
# Add configuration data
"config": {
"node_name": repeater_config.get("node_name", "Unknown"),
diff --git a/repeater/templates/nav.html b/repeater/templates/nav.html
index 95f9175..2d5368b 100644
--- a/repeater/templates/nav.html
+++ b/repeater/templates/nav.html
@@ -84,7 +84,27 @@
+
+
+
+
RF Noise Floor
+
+ --
+ dBm
+
+
+
+
+
+