Hacking a SPI LCD Display bus with Arduino

Hi, maybe you will find useful this sketch I wrote in order to use my UNO as a SPI sniffer.
I'm a newbe so It seems to me veeeery useful and simple.
I hope it would be useful for other newbe like me...

Thanks to the community from which I learned a lot...and found a lot of info...
...unfortunately I have found nothing very simple to let Arduino work both as slave and as sniffer in silent mode.

It works using the standard SPI.h library and ports... no new data structure, library or whatever...
very simple...

In my project I need to hack data through the SPI bus between an ECU and a LCD display 122x32 dots with a ST7920 chip (It is a very common display).
In this project I hacked the data protocol xcrossing oscilloscope reading and st7920 datasheet...
Unfortunately on the display there were no info about the chip used ...nor on googling because the display was an unknown type.... MS12232F
Anyway I performed hypothesys ("Spock! try to hypothesize!) and made a lot of try&error ...

I wrote as much comment as possible within the sketch.

cheers

LCD_ST7920_SPI_sniffer_v1.ino (7.33 KB)

1.jpg

LCD_ST7920_SPI_sniffer_v1.txt (7.49 KB)