As reported here: https://community.sparkfun.com/t/rtk-express-pvt-server-garbled-text/67200 `temp[]` needs to be increased to at least 31 to accommodate three lines of text: https://github.com/sparkfun/SparkFun_RTK_Firmware/blob/14630e4908c04718d8637326455c7e028857de44/Firmware/RTK_Surveyor/Display.ino#L2991