update

source/ConnectionChecker/ConnectionChecker.ino

@@ -0,0 +1,20 @@
+const int buttonPin = 2;     // the number of the pushbutton pin
+const int ledPin =  13;      // the number of the LED pin
+
+void setup() {
+  // initialize the LED pin as an output:
+  pinMode(ledPin, OUTPUT);      
+  // initialize the pushbutton pin as an input:
+  pinMode(buttonPin, INPUT);
+  digitalWrite(buttonPin, HIGH);  
+}
+
+void loop(){
+  int buttonState = digitalRead(buttonPin);
+  if (buttonState == LOW) {     
+    digitalWrite(ledPin, HIGH);  
+  } 
+  else {
+    digitalWrite(ledPin, LOW); 
+  }
+}