What type of help do you need? You quoted an app note, did you built it and it does not work? If so, what are the symptoms?
The X-10 protocol is based on house and device codes. For the data transmission to work, both the send and receive devices must be on the same house and device code.
After building the system, the easiest way to troubleshoot is to use existing X-10 devices, like the lamp module and the transmitter module. These are available at usually $10 to $20 each. Attach a lamp module to the power line at the same house and device code. If your transmitter can control the lamp module, but your LED cannot be controlled, then the problem is in your receive circuitry. If the lamp module or the LED works, then use the dedicated X-10 transmitter to verify that your receive circuit works the LED and troubleshoot your transmitter circuit.