limit gain increases to +34 dB

rx888.c

@@ -424,13 +424,15 @@ static void *agc_rx888(void *arg){
     if(frontend->rf_agc && (new_dBFS > AGC_upper_limit || new_dBFS < AGC_lower_limit)){
       float const target_level = (AGC_upper_limit + AGC_lower_limit)/2;
       float const new_gain = frontend->rf_gain - (new_dBFS - target_level);
-      if(Verbose)
-	fprintf(stdout,"Front end gain change from %.1f dB to %.1f dB\n",frontend->rf_gain,new_gain);
-      rx888_set_gain(sdr,new_gain,false);
-      // Change averaged value to speed convergence
-      frontend->if_power *= dB2power(target_level - new_dBFS);
-      // Unlatch high water mark
-      frontend->if_power_max = 0;
+      if(new_gain > 34){ // Don't try to go above max gain
+	if(Verbose)
+	  fprintf(stdout,"Front end gain change from %.1f dB to %.1f dB\n",frontend->rf_gain,new_gain);
+	rx888_set_gain(sdr,new_gain,false);
+	// Change averaged value to speed convergence
+	frontend->if_power *= dB2power(target_level - new_dBFS);
+	// Unlatch high water mark
+	frontend->if_power_max = 0;
+      }
     }
   }
   return NULL;