The best result i ever attained when using the LINX radio was achieved using a balanced code.

A balanced code ensures the propagation of equal numbers of ones and zero's per transmission. If you don't use a balanced code a "dc offset" accumulates and this is especially troublesome when signal levels drop. Manchester encoding is popular but i used a code balance where 8 bits were encoded in 12 bit format where 6 "1"'s and 6 "0"'s always propagated per byte.

Also as mentioned CRC is a requirement. I did some interesting things here. I noticed that the code balance technique allow a form of error correction if i emitted CRCs every 8 Bytes.

Any block of 8 bytes that didn't agree with a "balanced CRC" i would then look for single byte representations that were not in balance. If i found more than 1 byte representation unbalanced i would NAK the message. If i found my single byte representation out of balance i would "flip" bits" to attempt to correct the byte. If i couldn't "fix" the byte withing a timeout value i just Nak'd the message.

regards,
p