I-TTL Protocol Analyzer

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Connection of the Teensy 2.0 board as sniffer for Nikon I-TTL protocol

The board will be connected to the I-TTL bus using the following pin :

Teensy Pin	Project Name	Nikon name
0	/Sync X	X
1	Data	CSTP
2	/CLK	CRT/CRY
3	/Handshake	CSP

The board must be connected to PC using USB cable. USB will power the board. The ARDUINO software development tool must be installed including TeensyDuino add-on. Compile the program and download it. The protocol command and data are display on the serial Monitor windows of the tool.

Nikon shoe connection

To sniff the protocol I decide to modify a Metz TSC-20/NIK because easy to open (4 screw) and internal connection are soldered.

Picture of the tool…

and link to the Arduino sketch  Analyseur-iTTL_V0.ino