Hello,

The CPU Gopro is using is the Ambarella A2S.
Unfortunately I can't find any datasheet on the internet.

Hi all

I would like to refresh a bit this topic, as recently played a bit with the device on the bench. Hope, there is no other thread on this forum, as I don't wont to double the topic and make any mess.
First, I've had some doubts (same as halley in the first post) if this kind of informations should be published, but looking at lot of pictures flying around over the internet and other findings, this is not the case anymore I've send PM to Rambo about that, but looks like he is flying or paddling somewhere (nice homepage Rambo ) and I haven't got any replay yet.
So I decided to post some my findings here, as in my opinion - reveal functions of Hero Port will make the camera even better bestseller - GoPro should take this into account . I'm sure, people can find more good if they know how to use back connector instead of bunch of plugs and cables sticking from the side (e.g. FPV guys, can save some weight, less problems with pan/tilt heads).

This will be only a short part of the topic. Please feel free to read full thread posted on this forum: http://rc-cam.pl/viewtopic.php?t=2894 with a lot of pictures (it's in Polish, but I'm sure any of translating tools will have no problems with it).

Please find, that whatever you do is ON YOUR OWN RESPOSIBILITY ONLY! All below informations are posted for educational purposes only. Author takes no responsibility for any commercial or other than stated above usage of this informations.

Here we go:

As we know already, device is based on AMBARELLA SoC chip type A2S70-A1-RH:


Next interesting findings are on back connector PCB:


As you can see, there is a lot of marked goldpads, ready to be investigated

Below my presumed functions of the pins (this is applicable for the old/original software as I didn't updated my device yet):

G,R,B - this is related to video outputs. I found video switch IC on the board, responsible for switching video signals either to micro Jack outputs or to back connector. On my first attempt, I just pulled down appropriate input to low state, causing all video signals to be passed to Hero Port permanently, but only with conjunction with one of micro Jacks. Basically, there was enough to stick some plastic piece inside to open the contacts of the Jack's socket (yes, AMBARELLA senses that way, which socket is in use, and generates either normal or HD video). BE WARE OF ANY SHORTAGES - DO NOT USE ANY METAL FOR THAT PURPOSE, AS YOU GONNA FRY THE CHIP! Normal video (composite) you will find on R pin, others (when HD socket is triggered) are: componnent Y on G pin, Pb/Cb on R as well and Pr/Cr on B pin.


All of this is only in case of hardware modification, but without modification I found, that using pins ID1-4 we can switch the camera to rear connector output too. Those 4 pins are digital inputs in high state (+3,3V) pulled by RN1 pack resistor. So far discovered, that pulling ID2 low (wait few seconds), switches camera to "TEL"!! Unfortunately any of the video signals doesn't looks like "composite" (normal, low definition video), rather like composite or RGB. Hopefully with some more tests (combinations of those inputs) is possible to force AMBARELLA to throw some other formats through the port.

USB+5V, DM-B, DP-B - first one - no comments (you all know what this is) - Greg_E has discovered this already too. Other two - maybe second USB port's data pins - don't know yet.
HPL, HPR, IN1R, IN1L - audio outputs and inputs.
V3,6 - maybe external battery connection, in conjunction with WBAT+ - don't know yet.
IR_IN - sounds like infrared remote control receiver input - not tested yet.
TRIG - presume, this is counterpart of the top button, but as we know from correspondence with GoPro, this is not supported.
ADAPTER - no idea.
CLK, DATA - sounds like some synchronous serial interface (e.g. I2C), but CLK is quiet, only on DATA you can find some traffic. Looks like some UART transmission with 115200bps speed - to be analized.
DGND - common ground for all signals (yes - supposed to be only digital, but all grounds seems to be common).

Of course, those are not all pins from the port (30 pin), but looks like the most usefull - any way enough so far to play with I think.
Greg_E/halley - as you are on possession of breakboards already, I'm sure there will be easy to figure out the corresponding pins on the plug.

Once again, you are all welcome on the original thread, where you can find some more pictures.

B.Rgds

Pit

Very interesting, I had not thought to plug something into the video connectors to make a switch operate. I'll have to make a plug out of plastic and see which pin the video comes out on the breakout cable.

Hi Greg

I decided to go for it just out of curiosity, but my hands were shaking not only one time
Oh and forgot to mention before - video signals from bus Port need termination. Just connect 75ohm resistors between each output and ground. Jack sockets are terminated already.
Hope, there will be some progress on this topic.

Everybody,

I am looking for a way to have a master camera release a few slave cameras using the master cameras intervallometer.

So I purchased iPod connectors from Sparkfun and tested them with my GoPro HDs:
The "iPod Connector Male Style 1" fits really well: http://www.sparkfun.com/products/633

Didn't purchase nor test any of the other connectors available:
http://www.sparkfun.com/search/results? ... t=products

The breakout board:
http://www.sparkfun.com/products/8295

Jan

Hi Guys

Short update:

Found next analog switch, this time for USB signals:


So, as previously expected, pins DM-B and DP-B are signal lines for USB port and is the same port as the side one. Don't know yet how to operate this switch, but sooner or later we gonna find this too.

Please have a look at the Polish forum - there are some more, new pictures of heatsink and power supply chip.


Now, is time for me to take some rest - going for vacation. See you later and wish you Merry Christmas and a Happy New Year.

Don't forget that some pins could not be active yet until there is a new firmware release.

In communication over the internet about the GoPro i read about there should be a wireless transciever inside.
As they talk about wireless video display and wireless Stereo audio microphone.. I guess there should be a Bluetooth chip somewhere on there. (That would be the cheapest and easiest way. Bluetooth has already Microphones (thing about hands free for phone.. Those things that you put in your ear.)

Finally video is sorted a bit.. I did a extensive research on the 5018 chip but could not find a datasheet or something.

The other smaller chip is a Texas Instruments chip. AC3101i (Guess it's a i but not shure..)

Thank to GoProPit for pointing out there were references on the silk screen.. Anyone tested out if any pin will go high or power when you turn the GoPro on? This pin could then also be used as Indicator the connect a LED. I don't need a blinking LED a normal on is sufficient for me.

The HPL (HeadPhoneLineout) supprised me a little bit. This could mean that in the near future it will be possible to playback files on the LCD screen on the back. Playback previous recorded files.

Linein was what i was looking for!! I needed to have this for connecting a Headset configuration on it to record audio between driver and navigator. This will be my first mod.

Also in one button mode i can trigger on and off so i have the connections i needed for my project. Very well done guys.

Does anybody have the connector from sparkfun put into the Clear casing yet?

Greetings Daniel
Hardware Engineer and Camera men

Hi Xtreemtec,

I purchased a few plugs from Sparkfun.
They are tiny, but still to large to fit into the casing.
Pretty sure the new casing for LCD or Battery backpack will have enough space for the plug.

Jan

Xtreemtec wrote:
In communication over the internet about the GoPro i read about there should be a wireless transciever inside.
As they talk about wireless video display and wireless Stereo audio microphone.. I guess there should be a Bluetooth chip somewhere on there.

I doubt there would be Bluetooth chip, as they have always talked about a plug in wireless module for the rear port. The smart thing would have been to include it in the LCD and Battery Bacpak, but then not everyone wants the extra weight that comes with Bacpaks.

GoPro HDmk2-3 will see separation of hardware and further miniaturization. Total redesign, non camera like appearance. Camera head will Xmit wirelessly to main record unit/control/monitor (which will be like iphone).

Long time off yet, 2 years.

Okee i looked into the Sparkfun PCB. It quit huge alright..

I think i'm able to solder these >> http://www.sparkfun.com/products/9601

Then modify the case-ing a little bit to wire out on the side ..

How much space is there between the GoPro and the crash case-ing ?? Will it fit a 1cm or 0.8 mm connector on the backside? Don't have my GoPro's in the office yet. Waiting for a package to arrive in a few days...

Greets Daniel