Implement RSSI based squelch control

openrtx/src/state.c

@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <state.h>
 #include <battery.h>
+#include <hwconfig.h>
 #include <interfaces/platform.h>
 
 state_t state;
@@ -52,7 +53,11 @@ void state_init()
     state.channel.fm.txTone = 2; // 71.9Hz
 
     state.rtxStatus = RTX_OFF;
+#ifdef HAS_ABSOLUTE_KNOB // If the radio has an absolute position knob
+    state.sqlLevel = platform_getChSelector() - 1;
+#else
     state.sqlLevel = 3;
+#endif
     state.voxLevel = 0;
 
     state.emergency = false;

openrtx/src/threads.c

@@ -118,7 +118,7 @@ static void ui_task(void *arg)
             rtx_cfg.rxFrequency = state.channel.rx_frequency;
             rtx_cfg.txFrequency = state.channel.tx_frequency;
             rtx_cfg.txPower = state.channel.power;
-            rtx_cfg.sqlLevel = state.channel.squelch;
+            rtx_cfg.sqlLevel = state.sqlLevel;
             rtx_cfg.rxToneEn = state.channel.fm.rxToneEn;
             rtx_cfg.rxTone = ctcss_tone[state.channel.fm.rxTone];
             rtx_cfg.txToneEn = state.channel.fm.txToneEn;

openrtx/src/ui/ui.c

@@ -537,16 +537,18 @@ void _ui_fsm_menuMacro(kbd_msg_t msg, bool *sync_rtx) {
     }
 
 #ifdef HAS_ABSOLUTE_KNOB // If the radio has an absolute position knob
-    state.sqlLevel = platform_getChSelector();
-    printf("New squelch value: %d\n\r", state.sqlLevel);
-#else // Use left and right buttons or relative position knob
-    if(msg.keys && KEY_LEFT) {
-        state.sqlLevel++;
-        state.sqlLevel = (state.sqlLevel > 15) 15 : state.sqlLevel;
+    if(msg.keys & KEY_LEFT || msg.keys & KEY_RIGHT) {
+        state.sqlLevel = platform_getChSelector() - 1;
+        *sync_rtx = true;
     }
-    else if(msg.keys && KEY_RIGHT) {
-        state.sqlLevel--;
-        state.sqlLevel = (state.sqlLevel < 0) 0 : state.sqlLevel;
+#else // Use left and right buttons or relative position knob
+    if(msg.keys & KEY_LEFT) {
+        state.sqlLevel = (state.sqlLevel == 15) 15 : state.sqlLevel++;
+        *sync_rtx = true;
+    }
+    else if(msg.keys & KEY_RIGHT) {
+        state.sqlLevel = (state.sqlLevel == 0) 0 : state.sqlLevel--;
+        *sync_rtx = true;
     }
 #endif
 }

platform/drivers/baseband/rtx_MD3x0.c

@@ -410,17 +410,18 @@ void rtx_taskFunc()
 
     if(rtxStatus.opStatus == RX)
     {
-        /* Convert back voltage to ADC counts */
-        float sqlValue = (adc1_getMeasurement(1) * 4096.0f)/3300.0f;
-        uint16_t sqlLevel = ((uint16_t) sqlValue) >> 6;
+        // Unmute speaker if rssi is greater than squelch value
+        float rssi = rtx_getRssi();
+        // sqlValue represents 15 steps from -140dBm to -70dBm
+        float rssi_squelch = -140.0f + rtxStatus.sqlLevel * 70.0f / 15.0f;
 
-        if((gpio_readPin(SPK_MUTE) == 1) && (sqlLevel > sqlOpenTsh))
+        if((gpio_readPin(SPK_MUTE) == 1) && (rssi > rssi_squelch))
         {
             gpio_clearPin(SPK_MUTE);
             platform_ledOn(GREEN);
         }
 
-        if((gpio_readPin(SPK_MUTE) == 0) && (sqlLevel < sqlCloseTsh))
+        if((gpio_readPin(SPK_MUTE) == 0) && (rssi < rssi_squelch))
         {
             gpio_setPin(SPK_MUTE);
             platform_ledOff(GREEN);