OV7251 External Trigger (sync two OV7251)

Raspberry Pi Cameras mipi-camera-modules
1

1.Which seller did you purchase the product(s) from?

2.The Model number of the product(s) you have purchased?

3.Which Platform are you using the product(s) on?

4.Which instruction are you following?

5.Has your product ever worked properly?

6.What problems are you experiencing?
I am using 2 Arducam OV7251 boards (UC-545 Rev. C) with a StereoPi IO board (RPi 3 compute module). Everything is working great, but I would like to see if I can synchronize the two cameras better. There are connections for FSIN and Strobe on the boards and I am wondering if it’s possible to connect the Strobe of cam1 to the FSIN of cam2 and then configure cam2 shutter to go on FSIN (external trigger)? Can you let me know if that sounds like a feasible approach and if there is a software setting for the external trigger could you help me find where to set it (I am using the latest Arducam MIPI software from Github as of 2020-11-17).
7.What attempts at troubleshooting have you already made?

8.How would you like us to help you?

2

Hello,

This mode need to configure the sensor, and we don’t have this configuration now. We just have external mode configuration.

 

3

Thank you for your reply, but I don’t quite understand. “External mode configuration” is the correct thing to use isn’t it? Means to trigger the shutter on FSIN?

4

It looks like according to page 22 of the datasheet (http://www.datasheet-pdf.com/PDF/OV7251-Datasheet-OmniVision-1252892 ) that one sets 0x3005 to 1 (FSIN as an output) and then connects FSIN from cam 1 to FSIN on cam2 (and I guess we set cam2 like https://github.com/ArduCAM/MIPI_Camera/blob/master/RPI/ov9281_external_trigger.c ) ?

5

Hello, external mode has two type, Master mode and slave mode. all of our ov7251 is slave mode, which means, the sensor’s strobe signal is not output, you should use external trigger signal to trig the sensor instead of connecting the signal to another sensor’s strobe pin, If you want to conenct one camera’s strobe to another camera’s FSIN pin. For the first camera, you should configure it to master mode and ensure the strobe signal is normal. For the other camera, you should configure it to slave external mode. Now we just have external slave mode and we don’t have master configuration.