Waoo!! Brian nice, are u a EE or is this strictly an avocation. I can tell you from experience trouble shooting communication issues like this can be a trying time. I do have professional horror stories. I see you are from east CT. I still have family in Shelton. I also as I write this have I hope that I found my problem. Its the switch. I set up some counters on the program execution and the sensor was communicating motion but the light switch is not turning on. So what i thought was a faulty sensor can be a faulty Switch.