GRC Protocol Decoder

A simple way to decode a known protocol in GRC in real time. Once you've figured out the protocol a device uses, decoding it to view the transmitted values either requires writing them to a file and decoding them manually, or writing a custom GRC block to decode them in real time. This block will save you that last step, letting you quickly define a protocol so you can decode it and view transmitted values in GRC in real time.

Requirements

This is built to read the output of the Pattern Dump block in this repo: https://github.com/tkuester/gr-reveng You'll need to build that before using the block included here.

Samples

There's a sample cfile and GRC graph for you to test with. Install both gr-reveng and gr-protocoldecoder, then view the demos in the examples/ folder.

Usage - Protocol

You can describe a protocol by grouping bits and converting them to an appropriate value. Bits can be ignored, or optionally labelled. For example ignore.4 int.4 will convert the last 4 in a sequence to an integer, and the output will simply be, for example, 25. Groups can be labelled without affecting the parser. For example, ignore.4 label.deviceid int.4 will output: deviceid:25

ignore.4 will ignore 4 bits

label.sometext will prepend the next value with sometext:

bits.4 will just output the following 4 bits as they are

int.8 will take the next 8 bits, convert them to an integer, and add them to the output

hex.8 will take the next 8 bits, convert them to hex, and add them to the output

Usage - Input Format

This will decode bits according to common transmission schemes.

%[bits] will parse bits as they were given

%[man-bits] will manchester-decode bits, converting 10's into 1s and 01's into 0s before converting values

%[pwm-bits] will PWM-decode bits, converting 110's into 1s and 100's into 0s before converting values

Installation

make a directory called build, cd into it and run

cmake ..
make 
sudo make install