   // check all lines for incoming data
   for (int i=0;i<3;i++) if(bus[i]->available()) {
     char c = bus[i]->read();
+    if(SERIAL_DEBUG) Serial.println("received: "+c);
     switch(c) {
       case ALERT: // button is pressed
         if (!isSource && !alertState) {

#define leds2pin 3
#define button1pin 2 // not used
#define button2pin 4

#define ENERGY 0
#define DROPPING_CONNECTOR 254

int alertTimer;

void sendEnergy() {
  if(SERIAL_DEBUG) Serial.println("send energy");
  char c = ENERGY;
  for (int i=0; i<3; i++) bus[i]->write(c);
  addTimer(100, sendEnergy);
