skyplabs / pyhdlcontroller

Python HDLC controller

Python HDLC Controller

HDLC controller written in Python and based on the python4yahdlc Python module to encode and decode the HDLC frames.

Installation

From PyPI (recommended)

pip3 install --upgrade hdlcontroller

From sources

git clone https://github.com/SkypLabs/python-hdlc-controller.git
cd python-hdlc-controller
pip3 install --upgrade .

Documentation

The full documentation is available here.

License

MIT

pyhdlcontroller's Issues

local variable 'seq_no' referenced before assignment

In hdlcontroller.py line 260 seq_no is not defined. Must be defined before try-statement in line 229. Maybe seq_no=0

the controller is not working

Hi

I have setup a serial connection between two Linux machine and tried to communicate using this HDLC controller but sent message couldn't be received. The sender keeps trying to send the frame over and over again with no ACK signal from the receiver.

The code that I used is derived from your test with little additions. I am not sure why I could not get it to work. The code on both machines is this:

import threading, serial, time
from hdlcontroller.hdlcontroller import HDLController
from yahdlc import *

ser = serial.Serial(port = "/dev/ttyS0", baudrate = 9600, timeout = 0)

def read_serial():
    return ser.read(ser.in_waiting)

def send_callback(data):
    print('< {0}'.format(data))

def receive_callback(data):
    print('> {0}'.format(data))

hdlc_c = HDLController(read_serial, ser.write)
hdlc_c.set_send_callback(send_callback)
hdlc_c.set_receive_callback(receive_callback)
hdlc_c.start()

def readHDLC():
    while True:
        recvd = hdlc_c.get_data()
        print(recvd)

def writeHDLC():
    while True:
        strInput = input()
        hdlc_c.send(strInput)


readThread = threading.Thread(target=readHDLC)
writeThread = threading.Thread(target=writeHDLC)

readThread.start()
writeThread.start()

Best

Doesn't install in Windows

When trying to install in windows I get the following error:

ValueError: path '/home/travis/build/SkypLabs/python4yahdlc/lib/fcs16.c' cannot be absolute

HDLC on Ethernet port

Hi
Does your software make possible to receive data from HDLC frame on Linux on Ethernet port?

Example does not talk to ArduHDLC

What should read_uart return? Seems not to work with an bytearray like:
b'~Tst\xbe6~'

Which is the output of an arduino:

#include <Arduhdlc.h>

#define MAX_HDLC_FRAME_LENGTH 32
 
void send_character(uint8_t data);
void hdlc_command_router(const uint8_t *framebuffer, uint16_t framelength);
 
Arduhdlc hdlc(&send_character, &hdlc_command_router, MAX_HDLC_FRAME_LENGTH);
char framebuffer[MAX_HDLC_FRAME_LENGTH];
 
void send_character(uint8_t data) {
  Serial.print((char) data);
}

void hdlc_command_router(const uint8_t *framebuffer, uint16_t framelength) {
  // Do somethin here with the data in buffer
  return;
}

void setup() {
  Serial.begin(57600);
}

void loop() {
  framebuffer[0] = 'T';
  framebuffer[1] = 's';
  framebuffer[2] = 't';
  hdlc.frameDecode(framebuffer, 3);
  delay(500);
}

/*
SerialEvent occurs whenever a new data comes in the
hardware serial RX. This routine is run between each
time loop() runs, so using delay inside loop can delay
response. Multiple bytes of data may be available.
 */
void serialEvent() {
    while (Serial.available()) {
        // get the new byte:
        char inChar = (char) Serial.read();
        hdlc.charReceiver(inChar);
    }
}

If lib expects string: Not every bytearray can be decoded to a string, like example above. 0xbe can't be decoded

Splittig UART packages

Hi, wondering about when one HDLC frame is in two UART packages or if 2 HDLC frames are in 1 UART package. Should we implement splitting and concatenating UART packages (HDLC frames) ourself or should this be part of this library ?

In this example, I have to send the same frame twice as it is not recognized, because it is in 2 UART packages:

send data: b'~\xff\x10\x08\x01"!\x10\x00\x1a\x15\x08\x00\x10\x00\x18\x00"\x05extra*\x06gitrev"\x06\x08\x00\x10\x00\x18\x00\x1dU~' of len: 43
read data: b'~\xff\x01\x0e\xe1~~\xff\x10\x08\x01".\x10\x86' of len: 15
read data: b'\x12\x1a\x16\x08\x00\x10\x04\x18\x00"\x04-rc1*\x084354d098"\x11\x08\xb2\x80\xd0\x02\x10\xac\xc4\xaa\x93\x06\x18\xee\xd8\x91\xe3\x06\\\xa9~' of len: 47
send data: b'~\xff\x10\x08\x01"!\x10\x00\x1a\x15\x08\x00\x10\x00\x18\x00"\x05extra*\x06gitrev"\x06\x08\x00\x10\x00\x18\x00\x1dU~' of len: 43
read data: b'~\xff\x01\x0e\xe1~~' of len: 7
read data: b'\xff\x10\x08\x01".\x10\x86\x12\x1a\x16\x08\x00\x10\x04\x18\x00"\x04-rc1*\x084354d098"\x11\x08\xb2\x80\xd0\x02\x10\xac\xc4\xaa\x93\x06\x18\xee\xd8\x91\xe3\x06\\\xa9~' of len: 55
send data: b'~\xff!\x0c\xc0~' of len: 6

question: Does your controller handles SREJ frames?

Hello guys,

First of all, let me thank you for your work. It is nice to see initiatives like yours.
I have a situation where a series of frames are sent with segmented data in another layer.
One of these frames is rejected and a SREJ is sent back to me.
I would like to know if your controller handles SREJ and does re-transmission automatically.

BR,

Roberto

[Travis CI] Use the new build stages feature

Use the new build stages feature of Travis CI to deploy to PyPI only if all tests have passed successfully (and not only with Python 3.5 as it is the case at the moment).

serial.inWaiting() changed to serial.in_waiting

In newer versions of pySerial, method inWaiting() has been replaced by attribute in_waiting. See http://pyserial.readthedocs.io/en/latest/pyserial_api.html

Problem with instalation

Hello,

First, thanks for share your proyect. I will try to test but the instalation has a problem.

I do teh upgrade of the setuptools and wheel, but I can't solve this problem, Could you help me please?

Thanks
Juan Carlos

Raspberry pi and arduino communicate with hdlc protocol

I have found an hdlc lib for arduino from @jarkko-hautakorpi. I want use this python-hdlc-controller on PC/Raspbery pi and Arduhdlc on Arduino, could it work together?
https://github.com/jarkko-hautakorpi/Arduhdlc

Thanks!

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