GPS Development Board | ANTENOVA M20050-1 and ATGM332D-5N31

A KiCad breakout board for evaluating two GPS modules side by side — the ANTENOVA M20050-1 and the ATGM332D-5N31 — plus two footprints for 20 mm coin‑cell holders that keep the module's almanac powered for a warm start.

It is one of the breakout boards for the EJA "Intelligent Popup Buoy" project (2021 Hackaday Dream Team): every candidate part for the EJA M board was tried first on a small dedicated PCB. Both modules speak plain NMEA over UART and share an identical header pinout here, so the same firmware runs against either. The ATGM332D-5N31 was the one carried into EJA M.

Schematic

ANTENOVA M20050-1

Schematic of the GPS Dev Board: Circuit for the GPS ANTENOVA M20050-1.

ATGM332D-5N31

Schematic of the GPS Dev Board: Circuit for the GPS ATGM332D-5N31.

Additional Coin Battery Holders

Schematic of the GPS Dev Board: Circuit to test coin cell battery holders.

Bill of Materials

PCB

3D Model of the PCB design of the GPS Dev Board.

3D Model of the PCB design of the GPS Dev Board.

Firmware & Testing

The Firmware/ folder in the repository has an Arduino sketch for each module (esp32_atgm332d and esp32_antenova_m20050) — the same code with a different banner, since only one module is exercised at a time.

• The ESP32's Serial2 runs at 9600 baud on GPIO16 (RX) / GPIO17 (TX), wired to the module's UART header.
• The FuGPS library parses the NMEA stream; the sketch requests RMC + GGA sentences.
• On a fix it prints fix quality, satellite count, HDOP, altitude and a ready‑to‑click google.com/maps link with the current coordinates; if the module goes quiet for ~10 s it prints a "not responding" warning.

Test rig — the board's UART header wired to an ESP32; an active antenna goes on the U.FL connector.

Wire VIN→3V3, GND→GND, TX→GPIO16, RX→GPIO17, open the matching sketch (ESP32 board support + the FuGPS library installed) and watch the serial monitor at 115200 baud. A first outdoor fix takes a few minutes cold, seconds warm with the backup cell fitted.