First, the ATmega48V only has one UART. This is connected to the GPS module at 9600, 8N1. The connection to the GSM M-590 module is only 2400 bps, and slow enough for a bitbanged UART.

A 4G module is available as an option. Otherwise, a connection is established via Wi-Fi 6 and Bluetooth 5.2. Unitree also offers a GPS module as an option.