ip2uart

ip2uart is a lightweight bridge between a serial UART and a UDP peer. It batches outbound UDP traffic, uses epoll-driven I/O, and can inspect CRSF, MSP, or MAVLink telemetry frames for verbose troubleshooting output.

Features

• UART TTY backend for embedded serial devices.
• UDP peer mode with coalescing thresholds for throughput-friendly batching.
• Reloadable configuration via SIGHUP.
• Per-second transfer statistics when launched with -v.
• Optional telemetry parsing for CRSF, MSP, or MAVLink in verbose mode.

Building

The provided Makefile is Buildroot-friendly and honors typical cross-compilation variables.

make CROSS_COMPILE=aarch64-linux-gnu-  # build the ip2uart binary
make clean                              # remove the built binary

Installation

Use the install target to stage files into a root filesystem image or the live system.

make install DESTDIR=/tmp/rootfs PREFIX=/usr

The install step places the binary in ${PREFIX}/bin, the sample configuration in /etc, and the init script in /etc/init.d. Files are stripped when STRIP is available via CROSS_COMPILE.

Configuration

Runtime settings are read from /etc/ip2uart.conf by default. The file uses key=value pairs, and unsupported entries are ignored.

Important options include:

• uart_device, uart_baud, uart_databits, uart_parity, uart_stopbits, uart_flow for serial configuration.
• udp_bind_addr, udp_bind_port to define the local socket.
• udp_peer_addr, udp_peer_port to lock to a peer. Leave the peer address blank to auto-learn from inbound packets.
• udp_coalesce_bytes, udp_coalesce_idle_ms, udp_max_datagram to tune UDP batching.
• telemetry_proto (off, crsf, msp, or mavlink) to select parser mode.
• telemetry_coalesce to control frame coalescing behavior in telemetry mode.
• telemetry_msp_rate to control MSP polling frequency in MSP mode.
• rx_buf, tx_buf to size scratch buffers and ring buffers.

An example configuration is shipped as ip2uart.conf.

Runtime hints

• Send SIGHUP to reload configuration and reopen file descriptors.
• Use -v one or more times to print one-line transfer statistics each second.
• In telemetry mode, verbose output reports protocol counters by direction.