sr-spi-decode
small and fast SPI-decoder for Sigrok-captures, written in C
What is this?
This is a small tool that parses a Sigrok-capture (.sr) containing SPI-data, extracts all the bytes that have been sent (MOSI and optionally MISO) and spit them out as hex or binary. This is version 0.03 rewritten for libsr, see below.
Licence and Disclaimer
AGPLv3+ and NO WARRANTY!
How to compile
Dependencies
You will need libzip. On Debian you need libzip-dev. You will also need my own libsr.
Compiling
gcc -Wall -Wextra -Werror -O3 -o main libsr.c main.c -lzip
Usage
usage: $executable $filename $mode $channelname_CS $channelname_CLK $channelname_MOSI [$channelname_MISO]
$mode:
"print" -> print decoded values in hex
"binary" -> dump decoded values as raw binary (for piping to another tool or saving into a file)
As you can see it is pretty basic but it gets the job done and fast.
Beware: At this point this tool is mostly untested, expect bugs and other bad stuff.
Version 0.02 drops the "info" mode, just open the sr-file in Pulseview or use sigrok-cli.
Limitations
A lot: Linux-only, CS must be active low, SPI-mode is fixed to 0 (not 1 as written before), transfersize is fixed to 8 bits, ... However with some basic C-knowledge it should be easy and quick to adapt the code. I may upload a better version some day if i make one (=if i need one).
FAQ
Sigrok does have a SPI-decoder already?!
Yes and Sigrok/Pulseview is really a great tool, but there are two problems:
-sigrok-cli eats up all the RAM and makes my computer crash. (TODO: Investigate)
-Pulseview works fine and the new versions can save the data as binary, but it is really slow. I have a file with 1,3GB worth of captured data with about 7000 SPI-transactions. On my not-so-old computer Pulseview with the integrated decoder needs 30 minutes(!) and 3GB of RAM to process the entire thing. My tool, written in C and compiled with -O3, needs less than 10 seconds(!) and much less RAM too. Of course you won't get all the fancy graphical stuff that Pulseview offers. Note: Those numbers are old, i no longer have the capture to check with newer versions of Sigrok and my tool.
Why not improve Sigrok?
The Sigrok-decoders are written in Python which i don't know. Pulseview is written in C++ as far as i know, same problem. sigrok-cli is written in C and i may work on it at some point, but for the moment i needed a way to quickly get my SPI-data out of the captures so i made this tool.