The T-Beam ships with two options:
1) L76K
2) MAX-M10S
   
NMEA (National Marine Electronics Association) format is a standard protocol used for communication between marine electronics devices, including GPS receivers, chart plotters, and other navigation equipment. It's a text-based, ASCII-encoded format that transmits data in "sentences" — short, comma-separated strings that start with a dollar sign ($) and end with a checksum.

Key Characteristics:
Structure: Each sentence begins with $ followed by a talker ID (e.g., GP for GPS), a sentence type (e.g., GGA for Global Positioning System Fix Data), and data fields separated by commas. It ends with an asterisk (*) and a two-character hexadecimal checksum.
Example: $GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47
This is a GGA sentence providing time, latitude, longitude, fix quality, number of satellites, etc.
Common Sentence Types (relevant to GPS):
GGA: GPS fix data (position, time, satellites).
RMC: Recommended minimum navigation information (position, speed, course).
GSV: Satellites in view.
TXT: Text messages (e.g., module identification).
Baud Rate: Typically transmitted at 4800 or 9600 baud over serial interfaces.
Usage: Widely used in GPS modules like the L76K and UBLOX MAX-M10S, as seen in your project's code where NMEA sentences are parsed to extract location, time, and satellite data.
In your T-Beam exercises, the code reads serial data from the GPS module, buffers it into lines, and parses these NMEA sentences to detect the module type and extract useful information like UTC time and satellite counts. Both L76K and UBLOX modules output NMEA by default, though UBLOX can also support other formats like UBX binary. If you need details on parsing specific sentences or differences between modules, let me know!