An RS-232 to TCP bridge for legacy serial equipment. Reads from a serial port, writes to a TCP socket, and vice versa. Configurable. Fast enough.

Why This Exists

I needed to integrate a piece of lab equipment that had only a serial interface into a monitoring system that spoke TCP. The commercial solutions for this cost $400 and required Windows. This solution cost nothing and runs on a Raspberry Pi.

What's Interesting About It

Not much, technically. Serial-to-TCP bridges are a solved problem. The interesting part was the reliability work — making sure that a dropped TCP connection caused a clean reconnect without losing or duplicating data on the serial side, and handling the many ways that serial equipment can signal "I'm not talking to you right now" without actually closing a connection.

There's also a Python configuration layer that maps named devices to serial ports, manages multiple bridges simultaneously, and provides a minimal web status page.

The Real Reason I'm Including This

This is representative of a category of project I do regularly: something small, useful, not glamorous, that solves an actual problem and gets used for years. SerialGadget has been running continuously on a lab bench for seven years. I updated it once to handle a newer kernel's USB serial enumeration behavior. Otherwise it's just there, doing its job.

I think there's value in talking about these projects because a lot of engineering portfolio culture overweights the ambitious and underweights the reliable.