>My problems are on the preamble, sync word, and the checksum/CRC. >Basically, it's packet transmission and reception. Start by working on the preamble/sync byte portion. Forget about the CRC until you are able to transmit messages, and receive them. Then worry about the CRC for error detection once you can exchange the messages. This is all part of breaking the problem down. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body