radio link stats: handle RSSI_DBM slightly better

olliw42 · Dec 31, 2023 · 0a26282 · 0a26282
1 parent 1b4a4cb
commit 0a26282
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Showing 2 changed files with 9 additions and 9 deletions.
diff --git a/libraries/AP_RCProtocol/AP_RCProtocol_MavlinkRadio.cpp b/libraries/AP_RCProtocol/AP_RCProtocol_MavlinkRadio.cpp
@@ -58,17 +58,20 @@ void AP_RCProtocol_MAVLinkRadio::update_radio_link_stats(const mavlink_radio_lin
     }
 
     if (packet->flags & RADIO_LINK_STATS_FLAGS_RSSI_DBM) {
-        // rssi is in dBm, convert to AP rssi using the same logic as in CRSF driver
-        // AP rssi: -1 for unknown, 0 for no link, 255 for maximum link
-        if (_rssi < 50) {
+        // rssi is in negative dBm, 255 = unknown, 254 = no link connection, 0...253 = 0...-253 dBm
+        // convert to AP rssi using the same logic as in CRSF driver
+        // AP rssi: -1 for unknown, 0 for no link connection, 255 for maximum link
+        if (_rssi == 254) {
+            rssi = 0; // no connection
+        } else if (_rssi < 50) {
             rssi = 255;
         } else if (_rssi > 120) {
-            rssi = 0;
+            rssi = 1; // connection, but very low rssi
         } else {
-            rssi = int16_t(roundf((1.0f - (_rssi - 50.0f) / 70.0f) * 255.0f));
+            rssi = int16_t(roundf((1.0f - ((float)_rssi - 50.0f) / 70.0f) * 255.0f));
         }
     } else {
-        // _rssi is 0..254, scale it to 0..255 with rounding
+        // _rssi is in mavlink scale 0..254, scale it to 0..255 with rounding
         rssi = (_rssi * 255 + 127) / 254;
     }
 }

diff --git a/libraries/AP_RSSI/AP_RSSI.h b/libraries/AP_RSSI/AP_RSSI.h
@@ -49,9 +49,6 @@ class AP_RSSI
 
     // return true if rssi reading is enabled
     bool enabled() const { return RssiType(rssi_type.get()) != RssiType::TYPE_DISABLED; }
-//OW RADIOLINK
-    bool enabled(RssiType type) const { return RssiType(rssi_type.get()) == type; }
-//OWEND
 
     // Read the receiver RSSI value as a float 0.0f - 1.0f.
     // 0.0 represents weakest signal, 1.0 represents maximum signal.