scottp
dbed9bbc88
samples/shell is `rb9704` on the shell with callbacks that print what arrives, a CRC-32 and the start of each message from the network. Board overlays for native_sim (the modem a host serial port, a pty or a real 9704 on USB), NUCLEO-U575ZI-Q, XIAO ESP32S3 and ESP32-S3-DevKitC. tests/rig/bridge copies bytes between a board's USB serial port and a UART, so two boards wired together stand in for a USB-serial adapter: one runs the sample, the other bridges its modem UART to the host, where the fake modem answers. Overlays for a Nucleo and a XIAO, either way round.