Hardware hacking - need a little advice.

Discussion in 'Technology / Gadget Forum' started by daNtescpemstr, Aug 25, 2011.

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  1. daNtescpemstr

    daNtescpemstr bf2:doesnt get any better

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    Hi all.

    Because ever body works with computers on here and I couldn't find a decent forum to help I thought I would ask here.

    I bought myself an md 80 mini cam (£10 off ebay) I am going on a driving trip and want to film the journey. Unfortunately the battery wont last long enough and the memory isn't big enough. So I need to hack it!

    I am not/wont be in the situation where I can stop and download the data or run the camera from the in-car power.

    Battery:

    Say for example; the battery is 1.2v/1200mpa which last 30mins?

    if I got two 1.2v/1200mpa batteries to make 1.2v/2400mpa, would I be able to link the batteries together to make a cell? Or would I just need a bigger battery?

    Memory:

    At the moment it takes a micro SD card, up to 16gb? Which is good for about 8hours ish video, but the only thing is there not exactly cheap and I may not have the ability to download it every eve, so is there any thing I can use instead that is cheaper and holds a bigger memory?

    Or

    Is there a video receiver that could send it to a DVR sort of device. I don't want to go overly expensive hence why I am trying hardware hacks instead.

    Also I may need to access the device remotely, is 3G the only option or is there one that can work through the wireless that is cheap and be compatible with my device.

    If there is an easier alternative out there that is quite small and cheap I more than willing to take that on-board instead.
     
  2. brumster

    brumster Midland Muppet

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    Provided you linked them in parallel, that should work, yes.

    Might be better to make yourself a 12v->5v USB power supply though, assuming the camera can be powered by USB?

    A normal SD card is directly pin-compatible, if you consider that an alternative? Otherwise, SD cards basically have a serial memory interface very similar (if not identical, I think) to SPI, but you'd have to use something that implements it in exactly the same way - I doubt you'd find anything packaged up ready-to-use that's cheaper than a simple SD card anyway.

    Be a transmitter, not a receiver, if you want to send ;)
    I'm sure someone sells one but again, working out the interface between your camera (which presumably does not have any video outputs on it) would be a fairly monumental electronics project in itself unless someone's already done it.

    Blimey, this is a pretty massive project you're talking about :)

    If you're lucky there's a way of hacking the internal video stream to output it raw over the USB plug, but otherwise you'd have to hook into the data stream and use some sort of microcontroller interface to dump the video data over a wireless transceiver (doable; loads of chips in the microcontroller world that will do this, even development boards with it all on), but you're talking raw video data here, in whatever low-level format the internal ICs in the camera use. Better would be to maybe interrupt the flow of data into the memory card, which must be in some common format (MPEG4?). If you can interrupt it before it is translated into the FAT32 filesystem format written on the card, you could in theory be transmitting an MPEG4 video stream.

    What about a wireless web cam, that might align more with what you're trying to do and you've got less to do at the camera end as it's just a web server serving up a video stream... do your smart stuff at the client end by pulling in the video stream and doing whatever you want with it - write it to a file, dump it to a screen, etc...
     
  3. Archaon

    Archaon Eats, Drinks, Sleeps Kustom

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    Memory is a no-brainer. You can get a 16GB microSD for under £15 with free delivery - that ain't particularly expensive.

    For the battery, if it's got a mains charger (and will run when plugged in) then get a fag lighter > power socket inverter/adapter thing. If it charges off of USB then you can buy one which has a USB socket - Amazon have them around the £15 mark (or get a standard one and a mains > USB plug).
     
  4. gamerdude1989

    gamerdude1989 Banned

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    for the power, if it requires 1.2v, which would be a Nicad or a Nimh cell, Why not get a Lipo, (litium polymer) cell, ok their nominal voltage is 3.7v and 4.2v fully charged, but then you solder a voltage regulator on the positive, to constantly regulate it to 1.2v.
    lipo cells are fantastic for long life.
    a 1000mah Lipo lasts longer than a 2000mah Nicad / nimh.
    I use Lipo batteries in my rc cars, and they give fantastic run times.
     
  5. daNtescpemstr

    daNtescpemstr bf2:doesnt get any better

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    These are the specs of it.

    Description:
    Color: Black
    Material: Plastic
    Shape: Thumb
    Image Sensor: COMS
    Cmare: 2 Mega Pix els
    View Angle: 80 degree
    Endcoding: JPEG
    Video Resolution: 720*480
    Frame Rate: 30ftp
    Video Format: AVi
    USB : Compatible with USB 1.1 and 2.0
    Media Playing software: Attached software of the operating system or mainstream audio and video media playing software
    Operating System: Windows 2000 / XP / Vista
    Support TF&Micro SD card expended up to 8GB (not included)
    Battery: High-capacity lithium battery
    Battery capacity: 260mAh
    Work Time: About 2 hours
    Charge Time: About 3hours
    Operation Voltage: 3.7V
    Charging Voltage: DC 5V
    Work Circuit: 120ma
    Dimension: 52 * 21 * 20mm
    Net weight: 14g

    Would any of these do the job

    http://www.ebay.co.uk/itm/4x-3-7V-L...rElectronics_Batteries_SM&hash=item1e63ba1801

    http://www.ebay.co.uk/itm/18650-Lit...rElectronics_Batteries_SM&hash=item4aad4a7c31

    http://www.ebay.co.uk/itm/3-7V-2400...rElectronics_Batteries_SM&hash=item2a126a8114

    What sort of operation time do you think I would get from these batteries?
     
  6. gamerdude1989

    gamerdude1989 Banned

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    hi mate, unfortunately not, they are AA sized cells, therefor there is no way you will have a space to solder on a voltage regulator. (which is absolutely needed), 1.2v vs 3.7 well 4.2v fully charged, it will just blow the thing.

    Something like this would work well
    http://www.ebay.co.uk/itm/3-7V-1200...sGames_RadioControlled_JN&hash=item3366716d05

    1200mah with a 25C continuous discharger rate, which works out to be 30Ah, Then Concidering the device your wanting to mod is designed to run from something like an nicad / nimh, and low discharge rate.
    The Lipo cell would last a very long time.
    I couldnt possible tell you an estimate of roughly how long it will last per charge cycle, as i dont know the constant discharge rate of the device..
    But im imagining it will last a very long time indeed.
     
  7. daNtescpemstr

    daNtescpemstr bf2:doesnt get any better

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    Well it says

    "Operation Voltage: 3.7V
    Charging Voltage: DC 5V
    Work Circuit: 120ma"

    So those 3.7v batteries I posted should blow it/I wouldn't need a regulator would I?
     
  8. Ninjagordy

    Ninjagordy Winner of The Game (UJFL)

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    hi mate, the battery you listed is a li-po or lithium polymer battery anyway. you could buy a higher capacity lipo cell and solder connecting cables directly onto the pads as long as you had the correct orientation. this would increase the operational time by a large margin depending on the capacity of the cell , i use 4000mah lipo's for my rc cars and i can run 2 x 5 min heats with them and have spare left in them . with equivalent nimh i would get half the run time. shouldnt be too trick to do either!! be aware though. lipo cells are volatile if mishandled and charged incorectly or with the wrong charger. i have seen them burst into flames (check youtube)
     
  9. gamerdude1989

    gamerdude1989 Banned

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    yeah they are very good batteries ninjagordy, I run a 2S 7.4v in my 1.10 touring car race car, )Xray T3 2011 chassis.)
    and you sure are correct, they last me a good couple of races. easily
     
  10. brumster

    brumster Midland Muppet

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    Will it run while charging? The charging voltage is 5v, which implies USB. Therefore can you not just get an in-car USB power supply and run it off that? Or does the camera shut off when the charger is plugged in?
     
  11. Archaon

    Archaon Eats, Drinks, Sleeps Kustom

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    What I said before...16GB miniSD + car ciggy lighter adapter = £30. Job done.
     
  12. daNtescpemstr

    daNtescpemstr bf2:doesnt get any better

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    Can only take upto 8GB and I don't have a working cigarette lighter. So trumphs the usb idea, haha.
     
  13. daNtescpemstr

    daNtescpemstr bf2:doesnt get any better

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    I've broken it open and the battery says

    JU ZHAO
    0615331002
    3.7V 230 mAh

    Besides the end bit, does that mean anything to anyone?