NMEA-0183 serial bus decoding overview NMEA (National Marine Electronics Association) 0183 is a UART-based protocol that has been in use since 1983. Originally developed for marine applications, it can now be found in other varying applications such as GPS devices. It utilizes a sentence structure to send its messages and displays them in human-readable ASCII text strings - each sentence consists of a ‘$’ to indicate the start of a message, followed by a 2-character talker identifier, 3-character sentence identifier, relevant data fields specific to the sentence ID and then an optional checksum (denoted by ‘*’ followed by a 2-character hex checksum) before terminating the message with ‘’ (carriage return and line feed). Each field in the sentence is separated by a comma. Note that some manufacturers utilize proprietary sentence structures which may deviate from the specification.  More information on NMEA-0183 - serial protocol decoding >>