diff --git a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
index 450a8df..0b5391f 100644
--- a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
+++ b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
@@ -119,34 +119,37 @@ void calibrateAlert() {
 /*------------------------------------------------*/
 
 void adjustGain() {
-
-  if (GAIN_FACTOR == 0) {
-    pinMode(GADJ_R3, INPUT);
-    pinMode(GADJ_R2, INPUT);
+  switch (GAIN_FACTOR)
+  {
+  case 4:
+    pinMode(GADJ_R0, OUTPUT);
+    digitalWriteFast(GADJ_R0, LOW);
+    break;
+  case 3:
+    pinMode(GADJ_R1, OUTPUT);
+    digitalWriteFast(GADJ_R1, LOW);
+    pinMode(GADJ_R0, INPUT);
+    break;
+  case 2:
+    pinMode(GADJ_R2, OUTPUT);
+    digitalWriteFast(GADJ_R2, LOW);
     pinMode(GADJ_R1, INPUT);
     pinMode(GADJ_R0, INPUT);
-  }
-  else if (GAIN_FACTOR > 0) {
+    break;
+  case 1:
     pinMode(GADJ_R3, OUTPUT);
     digitalWriteFast(GADJ_R3, LOW);
     pinMode(GADJ_R2, INPUT);
     pinMode(GADJ_R1, INPUT);
     pinMode(GADJ_R0, INPUT);
-  }
-  else if (GAIN_FACTOR > 1) {
-    pinMode(GADJ_R2, OUTPUT);
-    digitalWriteFast(GADJ_R2, LOW);
+    break;
+  case 0:
+  default:
+    pinMode(GADJ_R3, INPUT);
+    pinMode(GADJ_R2, INPUT);
     pinMode(GADJ_R1, INPUT);
     pinMode(GADJ_R0, INPUT);
-  }
-  else if (GAIN_FACTOR > 2) {
-    pinMode(GADJ_R1, OUTPUT);
-    digitalWriteFast(GADJ_R1, LOW);
-    pinMode(GADJ_R0, INPUT);
-  }
-  else if (GAIN_FACTOR > 3) {
-    pinMode(GADJ_R0, OUTPUT);
-    digitalWriteFast(GADJ_R0, LOW);
+    break;
   }
 }