Reyax RYS352A Multi-GNSS Module w/ Embedded Antenna & UART Interface

Connect the module's VCC (2.5-3.6V) and GND pins to your power supply. Link the TXD pin to your microcontroller's UART RX pin and the RXD pin to the TX pin. On power-up, the module will output standard NMEA 0183 sentences over this serial interface at a default baud rate, which can typically be configured via proprietary UART commands. Use a serial monitor or parsing library in Arduino/PlatformIO to read the latitude, longitude, and time data.

The RTC (Real-Time Clock) battery backup powers a small internal memory that retains satellite almanac and ephemeris data, along with the current time, when main power is removed. This enables significantly faster Time-to-First-Fix (TTFF) during a 'hot start' (under 1 second) or 'warm start' compared to a 'cold start' where all data must be downloaded from scratch, which can take 30 seconds or more. It is essential for applications requiring quick positional fixes after waking from sleep.

No, the RYS352A is an integrated antenna module where the active GNSS antenna is embedded and not user-replaceable. The design includes internal SAW filters, LNA, and impedance matching specifically tuned for its built-in antenna. For applications requiring an external antenna, you would need to select a different Reyax module variant that features an MMCX or SMA connector for external antenna attachment.

The update rate is configured by sending specific proprietary UART commands to the module. The exact command set (often PMTK or UBX protocols) is detailed in the Reyax RYS352A technical datasheet. Typically, you would send a binary packet or an ASCII string via the RXD pin to command the receiver to increase its update rate from the default 1Hz to 10Hz. Ensure your microcontroller's serial buffer and processing loop can handle the increased data rate of 10 NMEA sentences per second.