diff --git a/Config.h b/Config.h
index 3eb0ed4..c68fba1 100644
--- a/Config.h
+++ b/Config.h
@@ -62,4 +62,3 @@
 // #define SERIAL_REPEATER
 
 #endif
-
diff --git a/IODue.cpp b/IODue.cpp
index 93faf35..4c41752 100644
--- a/IODue.cpp
+++ b/IODue.cpp
@@ -106,8 +106,10 @@ void CIO::startInt()
   ADC->ADC_IDR  = 0xFFFFFFFF;                 // Disable interrupts
   ADC->ADC_IER  = ADC_CHER_Chan;              // Enable End-Of-Conv interrupt
   ADC->ADC_CHDR = 0xFFFF;                     // Disable all channels
-  ADC->ADC_CHER = ADC_CHER_Chan |             // Enable rx input channel
-                  RSSI_CHER_Chan;             // and RSSI input
+  ADC->ADC_CHER = ADC_CHER_Chan;              // Enable rx input channel
+#if defined(RSSI_CHER_Chan)
+  ADC->ADC_CHER |= RSSI_CHER_Chan;            // and RSSI input
+#endif
   ADC->ADC_CGR  = 0x15555555;                 // All gains set to x1
   ADC->ADC_COR  = 0x00000000;                 // All offsets off
   ADC->ADC_MR   = (ADC->ADC_MR & 0xFFFFFFF0) | (1 << 1) | ADC_MR_TRGEN;  // 1 = trig source TIO from TC0
@@ -172,7 +174,11 @@ void CIO::interrupt(uint8_t source)
     sample = ADC->ADC_CDR[ADC_CDR_Chan];
     m_rxBuffer.put(sample, control);
 
+#if defined(RSSI_CHER_Chan) && defined(SEND_RSSI_DATA)
     m_rssiBuffer.put(ADC->ADC_CDR[RSSI_CDR_Chan]);
+#else
+    m_rssiBuffer.put(0U);
+#endif
 
     m_watchdog++;
   }
@@ -203,7 +209,7 @@ void CIO::setDStarInt(bool on)
   digitalWrite(PIN_DSTAR, on ? HIGH : LOW);
 }
 
-void CIO::setDMRInt(bool on) 
+void CIO::setDMRInt(bool on)
 {
   digitalWrite(PIN_DMR, on ? HIGH : LOW);
 }
@@ -213,10 +219,9 @@ void CIO::setYSFInt(bool on)
   digitalWrite(PIN_YSF, on ? HIGH : LOW);
 }
 
-void CIO::setP25Int(bool on) 
+void CIO::setP25Int(bool on)
 {
   digitalWrite(PIN_P25, on ? HIGH : LOW);
 }
 
 #endif
-