I've got a pinhole camera from an old drone that I dismantled a few years ago. It has a built in MicroSD reader, and 3 pins (red, black, and yellow). I'm wanting to repurpose the camera for use with an Arduino, but not sure how to communicate with it. If I recall correctly, the drone had the option to take a photo or video. I've connected the red wire into +5v, and black into GND, but not sure what to do with the yellow wire. I tried just writing a high signal with an Arduino to see if the camera would do anything, but it didn't work. An LED came on inside though, so it is being powered. Is there some common communication protocol for cameras like this I could use, or any advice on how I could initialize video recording with it? The drone is no longer functional, so I can't use that to determine the communication. Thanks!
Yellow is often a composite video signal. Connect an oscilloscope to it and see if it looks like a video signal.
From the Hackaday link:
There's a fourth pad by the yellow wire. That might be a digital input to trigger an image capture.
Check that extra pad and the yellow wire. See if either has 5V DC on it. If so, short it to ground through a low value resistor (1k or so) and see if that causes the module to store a photo on the SD card.
Outside of those possibilities, I don't see much you can do with that thing. You are kind of limited by not having a datasheet (or a model number or even a manufacturer name to try and find a datasheet.)
I encountered the same problem that you have, in my case, I am controlling a camera module for a SYMA X8C Venture drone. The board is probably completely identical to yours. The three pins are connected to a headphone jack, but I soldered on some wires to replace to hook it up to a breadboard so I could easily manipulate it.
Also, good thing to remember, if the module is not from an FPV drone or video streaming drone, then the yellow/brown cable is definitely not video output. It will also have an SD Card reader like yours.
I found these things when experimenting with it:
- The unit requires 5V DC and constantly draws 140-160mA.
- The unit can get pretty warm.
- When powered:
- If there is no SD Card inserted, the LED lights for about a second, then turns off.
- If there is, then it will flash green and red for another a second, then turn solid green.
- If an SD Card has been inserted after the LED turns off, it will immediately run solid green.
- Using the device:
- Before doing any of this, wait for the unit to turn solid green first.
- Remember to use a resistor when shorting. Any resistor above 1k ohms should be fine.
- Taking a picture: Short the yellow/brown pin to GND quickly (<1s). The unit will turn red for about a second and back to solid green. The picture will have then been taken.
- Taking a video: Short the yellow/brown pin to GND for a couple seconds. The unit will flash red, which signifies recording, until you short the two pins again. After that, it will turn solid green. The video will have then been recorded.
- The photos it produces are always 2560x1440 px JPGs, and the videos are 1280x720 px 30fps AVIs with a single 352kbps 22.050kHz sample rate audio channel.
- For videos, the metadata for "Contributing Artists" and "Origin" are set to "Generplus", and the "Year" is set to 2010.
- Sometimes the unit will glitch and produce an empty, junk video file.
- Upon insertion of the SD Card, if it is formatted/completely empty, the unit will create two directories named "PHOTO" and "VIDEO".
Here are a picture and video of my monitor taken with this camera: