Practical guidance for embedded developers designing custom communication protocols between MCUs and PCs or smartphones. Covers frame structure design including fixed headers with size, type, and sequence fields, payload byte-alignment and endianness choices for debuggability, and reserving bits for future use. Also addresses error detection via CRC, timeout and retry strategies for resynchronization, and using start codes to simplify debugging with logic analyzers and hex dumps. Recommends centralizing protocol handling in a single module and sharing a common spec file across firmware and host application.
