error message transmission now happens via uarthandler

StateMachine.cpp

@@ -1,4 +1,5 @@
 #include "StateMachine.hpp"
+#include "UartHandler.hpp"
 
 constexpr uint8_t ERROR_INDICATOR_LED_PIN = 3;
 
@@ -90,7 +91,8 @@ bool StateMachine::raiseError(const String &reason) noexcept
     state = STATE::ERROR;
     lastError = reason;
     digitalWrite(ERROR_INDICATOR_LED_PIN, HIGH);
-    if (Serial) {
-        Serial.println(String("Error!: ") + reason);
+    UartHandler& uart = UartHandler::getInstance();
+    if (uart.isOpen()) {
+        uart.send(String("Error!: ") + reason);
     }
 }