.\sx1272mb2das\NUCLEO_CUBE_LORA.axf: Error: L6218E: Undefined symbol readableU1 (referred from main.o).This error occurs.​​​char readableU1(void);​​void check_GPSBufferSize(void) {​ int currentBufferLength = readableU1(); if (currentBufferLength > 0)...

I want to get gps information using p nucleo lrwan1. Can I get an open source that can help? I'll use the uart port.(gps)