Samsung Galaxy Camera Mod

[jc0r]

Hi all

For a while now I have been working on a little project that would see me adapting a HD camera into a pair of binoculars for the purpose of streaming live video over Skype / Google hangouts etc whilst on the move.

I first looked at the radio control community where they use small cameras for first person viewing. Whilst these cameras were small enough for my needs, the quality of the image they produce wasn't really acceptable. Another issue I faced using this method is all the cameras in that community are analogue as they send the image feed over wireless transmitters, so I would need to convert that image to digital for use in video chat software.

I then looked at implementing a standard USB webcam hooked up to a small tablet PC, similar to techniques used by many amateur astronomers where they attach webcams to telescopes. After buying several higher end webcams, striping them down, I found this method to be to cumbersome. As a general rule, the higher the resolution of a webcam, naturally, the size of the device also increased. This is a problem for me as I would like to fit the device into the eye piece of one side of the binoculars so I can still use the other with my own eyes.

This brought me to where I am now. Looking for another solution, it suddenly dawned on me that I already own the device that ticks almost all the boxes, my Samsung Galaxy S5. The video quality of my phone when using applications like Skype far exceeded any webcam I had bought even though both were streaming 720p, and strangely enough, the amount of bandwidth I was using also decreased massively which is a factor for me as I am mobile and don't always have access to wifi networks. Using this method also gave me the luxury of not having to cart around a tablet PC.

A simple solution would be to use phone cases such as the following:



This however, is again, to cumbersome for my needs.

As the camera inside of my phone is very small, I started to think, why can't I just extend the flex cable inside and just have the camera module itself in the eyepiece of my binoculars? So this is what I set about doing.

After much searching, I came across this product:



Although this product is for a Samsung Galaxy S3, the amount of pins on the connector are the same as on the Galaxy S4 and S5. Having some idea of relative scale, I estimated the flex extender would be roughly 5cm long, this meant I was going to need quite a few of these extenders daisy chained together in order to get my phone out of the way of the binoculars. So I ordered 20 of them.

When they turned up, I began looking at teardown videos for a Galaxy S5, this was pretty much a none starter as the S5 been waterproof, requires you dismantling the screen in order to gain access. Nevemind I thought, I have a very understanding wife who also happens to own a Galaxy S4. I quickly dismantled her phone only to release, although the pin configuration was the same, the socket was slightly smaller, as can be seen here:



Not one to be deterred, I then contacted a friend of mine who owns a Galaxy S3. Knowing what im like, he agreed for me to teardown his phone. A couple of minutes later and his internal camera was now external and it worked! I then continued to add more extenders, this is where my moment of glory was short lived. 2 extenders connected, still working fine. Added the 3rd and the image cut in and out. I tried different extenders, same result. 4 extenders and the phone could not recognise the camera was connected.

This is where I am at now. I would like to add, no phones were harmed during this experiment

I came to the realisation that with every extra flex extender, there must be an increase in resistance which is stopping the camera from functioning properly. What I don't know is whether this extra resistance is been created by additional connecters in the loop or whether it is the length of the cable, or both. I started to think, if I could make, or have made a flex cable to my desired length (roughly 1m) thus eliminating all the extra connectors along the way, would this work?

I understand this has been a very long post and I appreciated your patience. If anyone can offer any advice whether a custom cable would work, where to get these made, or even still, a better solution that I have not considered I would be very thankful.

Once again, I thank you for your time

[Michaela Joy]

@jc0r: Your problem has nothing to do with the resistance of the cable; it's actually the capacitance of the cable (And the inductance to a certain extent) all of which is determined by the length of the cable. The longer the cable, the more ringing you get (extra signals and noise) After a certain length, the receiver on the board can no longer understand the data being sent.

:MJ

[jc0r]

Many thanks Michaela for your response. You'll have to forgive my knowledge with regards to resistance / capacitance, when I say resistance, I basically mean, something getting in the way I take on board what you are saying and will continue my research as an electronics noob. So to use an analogy, if the receiver on the board is a microphone, if I was to speak into the microphone, it would pick up my voice, but if I was to stand 100m away, it wouldn't pick anything up. So the only way to achieve what I am trying would be to have a more powerful receiver which in this case is not a viable option?

[Mechatrommer]

option 1) Samsung KZoom 10X zoom built in, 1920p 60fps capable 20Mpixels sensor, pros: not cumbersome, use as is. cons: expensive, cannot record 640x480 30fps or lesser
option 2) buy extension zoom unit specific to your S5 from ebay. pros: not cumbersome, use as is, cheap. cons: onehunglow quality can be subpar.
option 3) buy 3d printer, design and print bino holder for the S5, pros: you can use the 3d printer for other project. cons: cumbersome, expensive
option 4) your way above, pros: 0 investment as you already have most of the materials, only small cheap flex needed. cons: cumbersome, you risk damaging an expensive smartphone that you may passdown to folks or relatives.
ymmv.

Another issue I faced using this method is all the cameras in that community are analogue as they send the image feed over wireless transmitters, so I would need to convert that image to digital for use in video chat software.

you can buy rca/analog video input to usb output converter, no problemo its cheap as well.

[Grapsus]

Hi,

I'm not sure I understood exactly what you attempted, correct me if I'm wrong:
  - you'd like to mount a Galaxy s3 camera module on a cable instead of having the module inside the camera
  - you bought several flat-flex extenders for the connector that is used to connect the camera module to the motherboard
  - one extender worked fine
  - finally, that's the part I'm not sure about, you tried to daisy-chain several extenders in order to have 1m of cable length ?!

In short, and I could bet my hand on it, it will never work.

The camera module generates a huge amount of data, something like 8 Mpix * 8 bits * 30 fps ~= 2 Gbit/s of raw data. This data needs to go to the motherboard for processing, encoding etc. Therefore the interconnect that you're trying to extend is moving digital data at a tremendous speed, probably using a high-speed, differential signaling protocol like CSI. This protocol has been designed to work with short cables, inside a device. Now, there is probably a security margin because all connectors and solder joints have some tolerance, but the more connectors and cable length you will add, the bigger the probability of an error will be because the signal will become distorted, delayed etc. With 1m cables running outside the device the transmission failure is certain and the module cannot communicate with the motherboard at all.

Extending cables and adding connectors works with slow protocols like RS-232 where the security margin is huge, but high-speed protocols are closer to the physical limits of the transmission lines they use and it's not that simple. However, this fact doesn't prevent some ebay stores to sell you 5 meters PCI Express cables