Reuse old laptop camera - DELL Latitude E7440

Somewhile ago I found a movie about reusing parts from old laptops. There were a few interesting ideas, but this one I decided to try by my self. It was not a discovery for my, that those cameras are connected internally via USB. As you may expect, you will not find USB plug inside, so to reuse it need to be recreted. And about this is this article.

One day, I got in my hand broken laptop DELL Latitude E7440. I decided to use it for this experiment. Camera module inside is CN-07YYTT. It allows you to get a picture with resolution 1280x720. Do not impress. As you can see it is connected via micro connector. I was looking for pinout a lot, but I couldn't find any. Everything gets even more complicated if one notice two MEMS microphones on both edges of PCB. Fortunately, there are eight golden dots - test points on PCB. They are electricaly connected to this small connector and can be used to solder cables.

First important thing I have found in the internet was fact about power supply from 3,3V. Producer even put this info on PCB overlay. Some guys claims it can be supplied directly from 5V. It can not! Main camera controller is SN9C270A. I was clearly said in datasheet, that maximum ratings is 3,6V.

Absolute max ratings

That is why I've made 3,3V power supply on prefboard and LM1117.

Stablizator LM1117-33

Now, the last thing is to find purpose of each point. Finding ground is easy, because almost whole electronic parts are covered with metal shield connected to it. To identify USB lines I used original cable. Wrapping out main isolation I got bunch of colorful cables. Two of them are twisted and those are D+ and D-. The hardest thing is to find power supply. Interesting method presented one engineer on YT, who used CR2032 battery to supply this module and watched multimeter. Wire, which cause voltage drop due to controller and camera sensor start, is the one we look for. Using this method I found my VCC.

But after connecting all signals device was not recognized by computer. I lost one evening, before it turned out, that my old, long USB cable was really bad. Data lines inside were not twisted with length of over one meter. When I shorted it to 20cm device started spinning ;).

Device Manager

All my foundings and missing microphone signals I have veryfied with laptops schematics. Results below.

Rozkład wyprowadzeń CN07YYTT

On the end two shots of camera matrix under microscope:



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