HDLC

by Djones A. Boni

HDLC stads for High-Level Data Link Control. This library adapts the HDLC protocol for standard serial, allowing easy communication with CRC error detection among microcontrollers connected via a serial bus.

For more information about HDLC and take a look at RFC-1662 - PPP in HDLC-like Framing or in the doc/rfc1662.txt file.

Implemented as a C++ class template, the HDLC Data Link Layer can be extended using class inheritance. The library also provides an One Byte Transport Layer derived class template as an extension example.

You can use HDLC both for closed- and open-source projects. You are also free to keep changes to this library to yourself. However we'll enjoy your improvements and suggestions. :-)

You are free to copy, modify, and distribute HDLC with attribution under the terms of the Apache License Version 2.0. See the doc/LICENSE file for details.

Supported hardware

The project has been developed and tested with AVR microcontroller family (ATmega 2560) using Arduinutil as development platform.

However it should be very easy to port to another microcontroller family and development platform.

How to use HDLC

• Create an HDLC object
• Send data with HDLC
• Receive data with HDLC

#include "HDLC.h"
#include "Arduinutil.h"

HDLC<Serial1_read, Serial1_writeByte, 16> hdlc;

void hdlc_sendMsg() {
    uint8_t msg[] = "Hello world!";
    hdlc.transmitBlock(msg, sizeof(msg));
}

void hdlc_receiveMsg() {
    if(hdlc.receive() != 0U)
    {
        uint8_t buff[hdlc.RXBFLEN];
        uint16_t size = hdlc.copyReceivedMessage(buff);

        Serial_print("Msg[%u]=%s\n", size, buff);
    }
}

int main(void)
{
    init();
    Serial_begin(115200, SERIAL_8N1);
    Serial1_begin(19200, SERIAL_8N1);

    Serial_print("Init\n");

    hdlc_sendMsg();

    for(;;)
    {
        hdlc_receiveMsg();
    }
}

Contributing to HDLC

If you have suggestions for improving HDLC, please open an issue or pull request on GitHub.

Important files

README.md Fast introduction (this file).

doc/LICENCE Complete license text.