Serial to TCP Bridge Protocol
An error tolerant serial UART to TCP connection, raw data bridge.
Description
Host side gateway service written in Go that listens on COM ports for serial clients.
This is meant to bridge the gap between tcp connections and serial devices using UART/RS-232/Virtual COM over USB, etc.
Clients implementing the protocol client have a tcp like api that they can use to make connections to real servers.
The goal of the project is to have the means to connect the simplest and cheapest devices to the internet, albeit indirectly.
For now, I use this to connect microcontrollers on development boards to servers running on localhost through the Virtual COM port over USB, without requiring any Ethernet/Wi-Fi hardware.
Included in this repo is an implementation of the Protocol Gateway and Client, written in Go. They work on Windows, Linux and even Raspbian.
The following clients are also available:
| Client | Platform | Language |
|---|---|---|
| ArduinoSerialToTCPBridgeClient | Arduino | C++ |
| STM32SerialToTCPBridgeClient | STM32 | C |
Use
- Install Go and set your
$GOPATH. - Open a terminal, then run
go get -u github.com/RoanBrand/SerialToTCPBridgeProtocol. This will fetch dependencies and build the gateway service. - Copy the config.json example to $GOPATH/bin next to the binary and set it according to your configuration.
- Run the binary.
Details
- The protocol provides the app an in order, duplicates free and error checked byte stream by adding a CRC32 and simple retry mechanism. See this for background.
- The Protocol Gateway opens a real TCP connection to a set destination on behalf of the Protocol Client.
- The Protocol Client connects to the Protocol Gateway over a serial-like connection, which can possibly corrupt data.
- The client specifies the destination IPv4 address and port.
- The gateway forwards traffic bi-directionally, as long as tcp connection is open and serial line is good.
Tests
- Open a terminal, then run
go get -u github.com/RoanBrand/goBuffers. - In the terminal, change directory to the
protocolfolder inside the repository. - Run
go test -vin the terminal.
Future plans
- Add ping option to periodically test serial line and drop upstream connection if timeout.
- Multiple connections per client to servers.
- Capability to scan system and listen on all found COM ports for clients.
- Turn into OS service.