diff --git a/platformio.ini b/platformio.ini
index b133bed..2fb4226 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -24,7 +24,6 @@ upload_protocol = atmel-ice
 lib_deps = 
     ${env.lib_deps}
     SparkFun External EEPROM Arduino Library
-build_flags = -D ATSAMD21G
 
 [env:mega2560]
 platform = atmelavr
@@ -33,7 +32,6 @@ framework = arduino
 lib_deps = 
     ${env.lib_deps}
     DIO2
-build_flags = -D ATMEGA2560
 
 [env:mega328]
 platform = atmelavr
@@ -41,5 +39,4 @@ board = uno
 framework = arduino
 lib_deps = 
     ${env.lib_deps}
-    DIO2
-build_flags = -D ATMEGA328
\ No newline at end of file
+    DIO2
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 604633b..10584d5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -25,7 +25,7 @@ void waveform_IrqHandler() {
 }
 
 #if defined(ARDUINO_ARCH_SAMD)
-void SERCOM2_Handler()
+void SERCOM4_Handler()
 {   
     mainTrack->hdw.railcom_serial->IrqHandler();
 }
@@ -52,7 +52,7 @@ void setup() {
     EEStore::init();
 
 	JMRIParser::init(mainTrack, progTrack);       // Set up the string parser to accept commands from the interfaces
-	CommManager::showInitInfo();                
+	CommManager::showInitInfo();           
 }
 
 void loop() {