Wireless DVR Dongle - DIY

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paulham
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Joined: 09 May 2012, 12:35
Location: Potters Bar, Hertfordshire

Wireless DVR Dongle - DIY

Post by paulham » 28 Mar 2014, 13:15

Wireless DVR Dongle - DIY

There have been a lot of builds recently using cheap reversing camera 2.4 GHz transmitter/receivers or 5.8 GHz transmitter/receiver modules to wirelessly send camera data from the back of the scope to the heads up monitor.
This tutorial will cover the reversing camera receiver attached to a DVR but I won’t be going into detail on the transmitter. The wireless units may look the same from the outside but there are many different circuits used in these, they all should work in a similar way so this tutorial might not be exact. If your board looks different to mine then you will need to take some extra care to make sure you are connecting your wires to the correct places.


Parts Required
DVR - £125
Reversing Camera 2.4 GHz Wireless Modules - £8(Not identical to mine, but should still work)
MINI 2.5mm 90º Degree Jack to 2 RCA's - £2.09
Heat shrink
Velcro

Total Price - £10-15 (excluding DVR)

Tools Required
Soldering Iron
Solder
Wire cutters/Strippers
Small cross head screwdriver
Multimeter


Steps
Step 1
Take the receiver out of the plastic enclosure and examine the wire connections, basically there should be2 wires for power in & 2 wires for video out.

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The reversing devices are designed to work in a car which has 12v readily available. Our DVR’s have a Cam-In socket which can power a 5V CMOS camera, we will use this 5v to power the receiver.
The 2 wires going into the circuit for the power can be followed to a regulator (the thing which gets really hot). This is getting hot because it is dropping the input voltage of 12v down to a usable 5v which the wireless module wants and throwing the rest off as heat, wasting power. You can see if this is outputting 5v by probing it with a multimeter, the black probe on the ground tab and the red probe to the right leg for 12v input and left leg for 5v output.

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Follow the 5v output to somewhere else on the board that you can solder a wire to.


Step 2
Work out which position on your DVR that you want to attach the receiver to (with Velcro) then cut your cable with enough length. Strip the end of your wire to expose a Red (power), White (video) & 2 bare wires (ground).

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Your DVR might have a different pin out, check this with a multimeter if you are unsure.


Step 3
Solder your wires to the pads on the board. My board had silk screen print labels which made it easy for me to solder the connections.

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Cover the board with electrical tape so the ground wires do not short, cable tie or hot glue the wire to the board.


Step 4
Cover the board with heat shrink tubing to protect it from the elements and from shorting against anything metal it may come into contact with.

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Attach some velcro onto the wireless dongle and to the back of the DVR for easy removal.

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Conclusion
Turn on your DVR the dongle should start receiving video automatically.
This mod can be removed from your DVR very easily and it doesn’t require any extra batteries (your DVR battery might not last as long though).

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