树莓派4B 串口 配置GPS+PPS授时
https://www.cnblogs.com/zhaoo/p/19310117/raspberry-pi-4b-serial-port-configuration-gps-pps-timing-z1f1kr4 https://www.cnblogs.com/zhaoo/p/19310117/raspberry-pi-4b-serial-port-configuration-gps-pps-timing-z1f1kr4 https://www.cnblogs.com/zhaoo/p/19310117/raspberry-pi-4b-serial-port-configuration-gps-pps-timing-z1f1kr4