Ug-353 Gps Driver | Cross-Platform FREE |

The garbage was not NMEA sentences (which start with $GP or $GN ). It was random binary noise. Marta grabbed an oscilloscope: the UG-353’s TX was 3.3V, but the CM4’s RX was configured for 1.8V logic due to a broken device tree overlay. She fixed the config.txt :

dtoverlay=uart5,uart5_rx_pullup=on

stty -F /dev/ttyAMA5 9600 cs8 -cstopb -parenb Now cat /dev/ttyAMA5 showed garbage. Good—data was flowing. ug-353 gps driver

Now $GPGGA sentences appeared cleanly.

Marta checked the datasheet. UG-353 defaults to 9600 baud , but the Linux kernel expected 115200 for the UART. She fixed the stty settings: The garbage was not NMEA sentences (which start

Marta was a firmware engineer for a small agricultural robotics startup. Her team had just switched from an old U-Blox GPS to the UG-353 (a common, low-cost 10Hz GPS module with a UART interface). The robot’s navigation stack was failing. “No fix,” the logs said. “No fix.” She fixed the config

The UG-353 was wired to UART5 on a Raspberry Pi Compute Module 4. Marta had written a simple systemd service to start gpsd with the correct options: