TX/RX crossover, active antenna, MOSFET power-gating: wiring a UART GPS comes down to a few rules. And a slow GPS is not enough as telemetry.
Wiring a GPS module to an ESP32-S3 looks trivial. Three mistakes keep coming back, and each one yields a module that never gets a fix.
Wiring and antenna
The GPS TX goes to the ESP32 RX, and RX to TX. The crossover is mandatory. Wired straight, the UART stays silent with no error message.
Most of these modules need an active antenna. The antenna holds an amplifier powered by the RF pin. Without it, the module sees the sky but locks no satellite in an urban setting.
Power and rate
The module draws around 50 mA continuously during acquisition. On battery, that is a constant leak. A high-side MOSFET switch, driven by a GPIO, lets you cut the GPS off between two readings.
A consumer GPS outputs a position at a rate of 1 to 5 Hz. For plain navigation, that is enough. For fast-dynamics telemetry, it is too slow: between two frames the position is extrapolated and wrong. The GPS gives the absolute reference, not the fine dynamics.