APC220 Problem Communicating with each other (PC to Arduino or viceversa)

Hello arduino-er, just bought mine last week and having an awesome time for it. here is my quick questions.

  1. Arduino detect COM3(my com port) but i cant seem to send any command to arduino.
  2. I tried uploading the code using apc220, also failed (i noticed the 256bytes capabilities, but just trying).
  3. My code runs fine when using usb-powered at computer, but it wont run if i used adapter(the adapter is also using usb-cable to power the arduino). I set the code to blink once every loop for test purpose.
  4. I have no way of knowing if arduino is transferring data to my pc, since i cant even send from pc to arduino, much less test the reverse. Is there any way i can test if the arduino is transferring any data using COM3?
  5. I heard you cannot used usb-powered if i want to use APC220. Is that true? Do i need a battery then?
const int trigPin = 2;
const int echoPin = 4;
float temp;
int tempPin = 0;

void setup() {

void loop()

void room_heat_sensor()
  temp = analogRead(tempPin);
  temp = temp * 0.48828125;

void ultrasonic_sensor()
  long duration, inches, cm;

  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  digitalWrite(trigPin, HIGH);
  digitalWrite(trigPin, LOW);

  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH);

  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);
  Serial.print("in, ");

long microsecondsToInches(long microseconds)
  return microseconds / 74 / 2;

long microsecondsToCentimeters(long microseconds)
  return microseconds / 29 / 2;

p/s : i didnt connect the heat sensor and ultrasonic sensor in the pic below, but it still gives me random gibberish data continuously nonetheless.

|500x375 |500x375 |500x375 |500x375 |500x375

Below is some of the instruction i've followed http://www.swanrobotics.com/Wireless_Arduino http://fritzing.org/projects/wireless-arduino-with-apc220 http://www.appconwireless.com/NEWS/shownews.php?lang=en&id=6 and many others.

Any help is very much appreciated :)