Arduino Unio and xBee (series 1) radios configurationh help with PIR

Help me configure two xbee Series 1 radios (Coordinator and End Point) to communicate with each in 2 ways. 1) When a PIR attached to an End Point radio senses motion, I need that radio to notify the coordinator and a simple sketch that helps me to recognize the event. 2) I need the coordinator to send a message to the End Point which will trigger a relay. Ideally, the same sketch used in (1) would also be used to demonstrate this also. I would like a Fritzing diagram of the configuration along with necessary radio settings (XCTU screen shot or similiar). I am using the following components: -- Arduino Uno -- Series 1 xbee radios -- Adafruit xBee adapter - P126 ([login to view URL]) -- HC-SR501 PIR Sensor ([login to view URL]) I have all of the pieces and parts and have the configuration very close to working with option (1) above. However, I've invested a ton of time and need help finishing the project. I am software guy, not a hardware guy. I really need access to a resource that I can consult with regards to these sorts of configuration issues as my product works its way through development. So, I do expect ongoing tasks. A little more background... I got stuck on my build when I started to read about needing a pull down resistor with the PIR. Also, my End Point radio config is constantly sending data to the communicator that has nothing to do with the PIR action. I have a wire soldered to Pin 4 of the xbee adapter and somehow need to tell that end-point to only send a signal to the coordinator when motion is detected.