Try this
Couldn't download zbitx_front_panel_sw.ino.uf2 from HFSIGNALS page. ? Downloaded code from zBitx page.- zbitx_front_panel_sw.ino.uf2 dated 3/30 9:15 AM. ? Xfer to zBitx - no response (stays on gray screen) ? Xfer v1.04 and zBitx reboots to 1.04.........