Module codec 

Frame-level codec for \r-terminated CAT protocol messages.

The TH-D75 CAT protocol uses carriage return (\r, 0x0D) as the frame delimiter for both commands and responses. Each message is a sequence of ASCII bytes terminated by a single \r. There is no length prefix or checksum — framing relies entirely on the delimiter.

This codec sits between the raw serial byte stream and the protocol parser. The data flow is:

Serial port  -->  Codec::feed()  -->  Codec::next_frame()  -->  parse()
             raw bytes          buffered             complete frame    typed Response

On the transmit side, super::serialize produces the wire bytes (including the trailing \r) that are written directly to the serial port — the codec is not involved in outbound framing.

The codec maintains an internal buffer that accumulates bytes from successive Codec::feed calls. When Codec::next_frame finds a \r, it extracts everything before it as a complete frame (without the delimiter) and drains those bytes from the buffer. The buffer is capped at 64 KB to prevent unbounded growth if the serial link delivers noise without any \r terminators.

Structs

Codec

Frame-level codec for \r-terminated CAT protocol messages.