Synchronize the color lens of D435I with an external sensor

[JasonWang9805]

Required Info
Camera Model	{ D435i }
Firmware Version	(Open RealSense Viewer --> Click info)
Operating System & Version	{ Linux (Ubuntu 18/20/22) }
Kernel Version (Linux Only)	(e.g. 5.4)
Platform	NVIDIA Jetson
Librealsense SDK Version	{ 2.<?>.<?> }
Language	{C/C#/labview/opencv/pcl/python/unity }
Segment	{Robot/Smartphone/VR/AR/others }
ROS Distro	{Iron/Humble/Rolling/etc.. }
RealSense ROS Wrapper Version	{4.51.1, 4.54.1, etc..}

Hello. When the Intel RealSense D435I is in slave mode and using external triggering, does the trigger voltage have to be 1.8V? Can it be replaced with 3.3V instead?

[MartyG-RealSense]

Hi @JasonWang9805 Yes, the external trigger pulse's voltage has to be 1.8V in order to work with Pin 5 (the sync pin) on the slave camera.

If generating a 1.8V trigger is a problem for your external trigger equipment then you could generate a 3.3V pulse and then use an electronics component called a voltage shifter, or level shifter, to reduce the 3.3V to 1.8V so it works with the camera. An example of a level shifter that should work is the SparkFun one referenced at https://github.com/IntelRealSense/librealsense/issues/12064#issuecomment-1661991065