serial

serial

This is an extended package for accessing the serial port. It is inspired by https://github.com/tarm/serial and several forks.

I made this library mainly for educational purposes. As you can see, I commented my code a lot, just to make myself clear what is happening.

Additionally, I will try to collect useful information in the repo-wiki

This package is currently untested.

Overview

• Library
• serial2http
• Terminal

Library

The connection struct is all you need. It encapsulates all parameters necessary and all functions needed to interact with a serial device. Just initiate a connection and open it. After that, you are able to read and write from it or to flush the I/O. When you are finished, just close it.

A connection can be initiated by setting all parameters within the code or by loading all parameters from a file. The library provides several consts to set the baud rate, data and stop bits as well as the parity.

Using the Init function:

connection, err := serial.InitConnection("/dev/ttyUSB0", serial.Baud115200, serial.DataBit8, serial.StopBit1, serial.ParityNone)

Loading from a file:

connection, err := serial.LoadConnection("sample/connection.json")

The next step is to open the connection:

err := connection.Open(0)

This simply sets up the underlying file and binds the desired parameters to it. The 0 is indicating that no timeout is being used. The file is blocking until at least one byte is received.

Writing to the serial port is done by just calling the write function:

n, err := connection.Write([]byte("WriteToPort"))

This returns the count of transmitted bytes as well as the error.

Reading from the serial port requires a delimiter, which indicates the end of the transmission:

response, err := connection.Read(10)

The delimiter is device dependent. Using an ASCII table to find the correct decimal value may help at this point. The response is a []byte, which contains all data transmitted until the delimiter is reached.

Another way for reading from the port is to use a buffer.

response, err := connection.ReadToBuffer(256)

This will read all bytes into a []byte with the given size.

After finishing reading and writing, the connection can be flushed and closed:

err := connection.Flush()

This causes the I/O to discard not transmitted and unread data.

err := connection.Close()

This causes the connection to be closed.

Possible Errors

• invalid baud rate
• invalid data bits
• invalid stop bits
• invalid parity
• connection not open
  • should only occur when trying to write or read
  • solution: execute connection.Open() before trying to write or read

serial2http

Terminal