So, I bought a GoPro HD camera. But, my camera is mounted on the main-hoop diagonal, and I can’t reach it from the driver’s seat while buckled in. This last weekend that meant starting the camera when I got to the grid, then starting the process of buckling up, putting on my helmet, and waiting to be released from the grid. As many people have noted that results in about 8 minutes of dead video at the front of every recording. There has to be a better way!!!
In comes the gopro user forum: http://goprouser.freeforums.org/the-gopro-hero-hd-bus-interface-t797.html
These folks have hacked the entire herobus connector on the back of the HD camera. All I want to do is wire up a switch, an ON indicator, and power. That way I can turn on the camera from a dash mounted switch, have a light when the camera is ON, and run the camera off car power so I don’t have to worry about the internal battery.
These guys have figured out how to control the shutter, and do all sorts of crazy things with the cameras. Enjoy.
Connections
For the Pinout… I listed ALL ground pins. More grounding is always better. I recommend using all ground pins.
1 GND
5 USB +5V USB power
9 GND
12 PWR/MODE power/mode button
14 AUDIO IN RIGHT Line level audio input signal, right side
15 AUDIO IN LEFT Line level audio input signal, left side
18 GND
23 ADAPTER output – power for ext. adapter? ~3.6V when camera is ON.
27 GND
30 GND
wire pins 12 and 18 to each side of a momentary (normally open) push button or toggle (puch to close contact)
wire pins 23 and 30 to each side of a LED via a ~150 ohm resistor.
wire pins 5 and 9 to each side of output of a cigarette lighter USB power supply
Just be sure you are counting from the same end of the connector as described in the post dated “Tue Jan 11, 2011 11:40 pm” below.
The 150 ohm resistor gives about 1.3mA through the LED…adjust, as needed, per your selected LED. So, that’s 3 twisted pairs of wires. Since its DC you could get away with untwisted. Shielded cable would be recommended. Only ground one end of the shield. I would ground at the CHASSIS end of the cable—not the camera end. This is because any noise coupled onto the shield would have to travel back through the ground wires in the cable bundle. That puts the noise in with the signal wires…not really the point of a shield!
Parts
Digikey has the bare connector: http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=DD1P030MA1
GoPro LCD Backpack cover – email me for ideas on how to get one of these
USB cell-phone car charger (any old one will do). I chose one with a pig-tail attached rather that one with a standard USB receptacle.
Copper PCB material, etch-masking pen (1/32″ line thickness) + Feric Chloride or other copper etching solution
Cat5 or Cat6 wire + RJ45 crimp connectors (you could also buy pre-made ethernet cables and cut the ends into strategic lengths.
Female-Female RJ45 adaptor
Desired color LED indicator
USB Power Supply
Here are the bare parts stripped out of the cig-lighter plug. 12V input is on the right (withe spring), 5V output is on the left (by the red LED).
When I first opened it up the components were standing pretty tall. There is just under 1/2″ of space inside the GoPro LCD backpack cover. So, I needed to “shorten it a little bit. Perhaps with some searching a more compact power supply could be found. I have a soldering iron, and the skills. So, I desoldered a couple components, and moved them around so they would lay flat.
Next was to mock-up the circuit board. The inside of the GoPro case is 1 11/16″ x 2 5/16″. So, I’m making my PCB 1/16″ shy in both directions: 1 5/8″ x 2 1/4″. I found a picture of the bare GoPro camera online, a loaded it into PaintShopPro and corrected the perspective, then printed it out at 1:1 scale. That gives me a reference for where the HeroBus connector will be located and therefore where the USB board will need to be located.
Here is the mock-up inside the LCD cover.
Connector
In the same thread, another guy in the forum figured out how to mount the connector at a 90 degree angle to a printed circuit board.
http://goprouser.freeforums.org/the-gopro-hero-hd-bus-interface-t797-140.html
This is my plan.
PCB
I’ve done a PCB layout for the circuitry that goes in the box with the camera. This provides connections for 12V power, ON/OFF button, LED output, and L/R audio input. The trapezoid in the center is the cutout for the USB power-supply. The 2pin headers are for the USB power supply connections (12V in, 5V out).
I may end up removing the unused pins from the GoPro connector. This will allow me to enlarge the pins for more pain-free soldering. At 1mm pitch, they are pretty tight.
Installation
I decided to use Cat6 ethernet cable for the installation. I used the brown pair for the on/off button, the green pair for the ON/OFF LED, and the orange pair for the 12V power. I put a RJ45 crimp connector on the end, and will use a FEMALE-FEMALE adapter to connect to the harness wiring. Again, I’ll use the female-female thing to connect to the camera end.
Now, I just need a camera.
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