Welcome
Welcome to goprouser

You are currently viewing our boards as a guest, which gives you full access to view most discussions and access.. By joining our free community, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content, and access many other special features. In addition, registered members also see less advertisements if any. Registration is fast, simple, and absolutely free, so please, join our community today! Any issues email goprousergroup@gmail.com

the GoPro Hero HD "bus" interface *MOVED* see last post

Gopro User forum. This Old Forum is unlocked but ARCHIVED

Re: the GoPro Hero HD "bus" interface

Postby janmartin » Tue Jan 11, 2011 9:12 am

There are maybe 2mm, if at all.
So no plug will fit inside the normal casing.
Even when bending all the pins, the gray plastic of the plug itself is to large.

You need the new casing from the backpack (without the backpack) to gain the space needed.
janmartin
 
Posts: 81
Joined: Thu Jul 01, 2010 8:12 am


Re: the GoPro Hero HD "bus" interface

Postby Greg_E » Tue Jan 11, 2011 2:42 pm

I think to get usable life out of the system, you really need to have the larger battery to use with wireless connections. I'm waiting for the LCD backpack to get a little more info about what is going on with that connector. What we need in the shutter button (still not found) and the LED status to make a good remote. Then I need to investigate a couple bluetooth devices that are already licensed in most countries. It is very possible that for about $70USD there could be a DIY remote power, record start/stop, and status LED. To do video on Bluetooth you just about need an encoder chip to make a compressed stream.
http://transportcontrols.com
Updated with version 1.
User avatar
Greg_E
 
Posts: 1646
Joined: Thu Jan 28, 2010 7:39 am

Re: the GoPro Hero HD "bus" interface

Postby gopropit » Wed Jan 12, 2011 12:40 am

Hi guys

Sorry for long absence. In meantime I had some luck with interesting documents found over the internet:
1)service manual of very similar camera: http://wenku.baidu.com/view/b37abd4ffe4733687e21aa60.html
2)analyze of ASCII strings from new GoPro firmware: http://chdk.setepontos.com/index.php?topic=5890.0

Finnaly, please find below full pinout of herobus connector. Numbering is based on iPod plug as follows:
Image

1 GND
2 R video out - component Pb/Cb or composite
3 G video out - component Y
4 B video out - component Pr/Cr
5 USB +5V USB power
6 USB +5V USB power
7 USB DP-B USB data line D+
8 USB DM-B USB data line D-
9 GND
10 HPR audio out right channel
11 HPL audio out left channel
12 PWR/MODE power/mode button
13 V3.6 ?
14 IN1R audio in right channel
15 IN1L audio in left channel
16 IR IN input IR receiver
17 TRIG ?
18 GND
19 ID1 digital input
20 ID2 digital input
21 ID3 digital input
22 ID4 digital input
23 ADAPTER output - power for ext. adapter?
24 ADAPTER output - power for ext. adapter?
25 WBAT+ input - ext. power for camera?
26 WBAT+ input - ext. power for camera?
27 GND
28 DATA interface I2C
29 CLK interface I2C
30 GND

You probably noticed some question marks - those are FUNCTIONS of the pins I'm not sure of, but names and connections to the circuit are correct.
Some description:
- video out - in order to get composite (standard quality) video out of the bus, pins 20 (ID2) and 21 (ID3) must go low (can be shorted to GND). Camera will switch to "TEL" mode and on pin 2 (R) you will find what we were looking for. In order to get HD quality (componnent), just pull only pin 20 (ID2) down. Be aware, those outputs need 75ohm termination - just simply solder 75ohm resistors between each output and the GND;
- USB - power pins are doubled to maintain more current during charging. Data pins in turn, I been not able to make any connection by this port (tried all combinations of ID1-4 inputs without luck);
- HPR/HPL - audio out, operational when video switched to herobus. Unfortunately found voice only on one channel - HPR so far. Maybe by using IN1R/IN1L, stereo sound can be recorded and played - to be investigated (Xtreemtec is on the case I believe - go ahead and let us know);
- PWR/MODE - this pin has straight connection to the front button (hooray GoPro!). Basically it acts in the same way as this button, by pulling it down (to the GND as the button does) we can turn camera on/off, change mode etc. With new software and "One Button Mode", this can be used to take snapshots, start/stop recording and all source of things (I'm sure Janmartin will enjoy of that function);
- V3.6 - and this is mistery still. On that pin there is steady +2,5VDC and I have no idea what this pin can be for so far;
- IR IN - I've tried a lot of remote controllers with remote receiver connected to this pin but without luck. Looking at similar devices, such as Kodak Zi6, Zi8: http://code.google.com/p/openkodak/updates/list, based on almost same components and comparing those firmwares and GoPro firmware I came to the conclusion that IR control is not implemented yet in our device.
- TRIG - and here is the devil - since the beginning I thought this is external shutter or something similar. Recent findings revealed that this is digital output. It does nothing in video mode, but goes down as soon as first photo is taken (in all photo modes) and stays down untill mode is changed back to video or camera is turned off/on. A bit strange function, for me more usefull could be short pulse down after each picture or something similar - anyway if somebody have idea how to use it please comment (please find, I'm still using old firmware, maybe new firmware changed that behaviour - once again comments welcome);
- ID1-4 - so far, only input 2 and 3 made some reaction of camera (video output). Function of 1 and 4 unknown;
- ADAPTER - looks like this is power output to feed external adapters (such as LCD). Voltage on those pins (doubled for more current) follows battery voltage during usage and is turned on/off toogether with camera by (most probably) some transistor key;
- WBAT+ - this is the best candidate for external battery connection (doubled also for more power capability). There is ~0VDC during normal usage, but ~ +4,3VDC when USB power is connected (some voltage drop on diode? 5V-0,6(0,7)V=4,3V) - to be verified;
- DATA,CLK - forget about my previous findings. This is I2C interface. During starting, you can capture configuration data for both audio codec and video sensor.
First (audio codec) is TLV320AIC3101 from Texas Instruments. It's I2C adreses are: 0x30[hex] for write and 0x31[hex] for read the registers.
Second (video sensor) is MT9P401 from MICRON. It's I2C adresses are: 0xBA[hex] for write and 0xBB[hex] for read the registers.
Ambarella is a master on this bus. I'm still working on that and trying to capture data for all modes.

For those, who are interested, some datasheets:
TLV320AIC3101: http://focus.ti.com/docs/prod/folders/print/tlv320aic3101.html?lpos=Middle_Container&lid=Alternative_Devices
MT9P401 (datasheet on 6th page): http://www.iwimage.com/download.asp?BigClassName=&SmallClassName=
SGM5018: http://www.datasheetarchive.com/SGM5018-datasheet.html
Last edited by gopropit on Wed Jan 12, 2011 6:02 am, edited 1 time in total.
gopropit
 
Posts: 30
Joined: Sat Dec 11, 2010 4:32 pm

Re: the GoPro Hero HD "bus" interface

Postby janmartin » Wed Jan 12, 2011 1:33 am

Hi gopropit,

wow. Nice findings.

We nearly have everything I need (USB +5V, GND, ON/MODE), except the shutter release button.
Unfortunately switching the camera on/off to take advantage of the single button mode to take an single image is not really an option. I can confirm however that when using an external Intervalometer wired to the release button and GND, one can reliably take an image every 2 seconds. Which is also the minimal interval available in interval mode.

I guess its time for you to update to the new firmware, then see if the shutter release pin can be found?

JanMartin
janmartin
 
Posts: 81
Joined: Thu Jul 01, 2010 8:12 am

Re: the GoPro Hero HD "bus" interface

Postby Greg_E » Wed Jan 12, 2011 2:02 am

I assume that ID1 through 4 are pulled low to make them function? Seems like if you pull one or two of them low to get video output to work, you probably need to also pull one or two low to get external audio inputs to work.

What happens on the i2c bus when the shutter button is pressed? Seems like that is the last way to start and stop the recorder and might actually be easier to make a bluetooth wireless remote than using a contact closure. Things like the cheap RN-42 are happy to send data, but making them do contact closure is not so easy. I guess I need to solder some headers to my Sparkfun break out board and start playing. Thanks for doing the dirty work inside the camera.
http://transportcontrols.com
Updated with version 1.
User avatar
Greg_E
 
Posts: 1646
Joined: Thu Jan 28, 2010 7:39 am

Re: the GoPro Hero HD "bus" interface

Postby gopropit » Wed Jan 12, 2011 2:51 am

I assume that ID1 through 4 are pulled low to make them function? Seems like if you pull one or two of them low to get video output to work, you probably need to also pull one or two low to get external audio inputs to work.


That is true, pins ID1-4 are digital inputs, pulled up by 10kohm resistors. In order to "activate" each input, just pull (tie down) to GND. Audio inputs are not my priority now, so I let this case for others.

What happens on the i2c bus when the shutter button is pressed? Seems like that is the last way to start and stop the recorder and might actually be easier to make a bluetooth wireless remote than using a contact closure. Things like the cheap RN-42 are happy to send data, but making them do contact closure is not so easy. I guess I need to solder some headers to my Sparkfun break out board and start playing. Thanks for doing the dirty work inside the camera.


That's why I focused on I2C now, as I don't see more choices for remote trigger.
Please find attached "init" traffic on I2C bus captured recently. "Picture" capture or video start/stop data are not ready yet (but for sure, there are sequences for starting and stopping recording, picture). However, I don't have an experience with multimaster on I2C bus, as any external device should act as second master (the first is Ambarella). Maybe, there is possible to control Ambarella by this interface as well, but we must find proper adresses, registers and other data first.

It is good that you raised the issue of wireless communication. I've been looking at the picture of front PCB and this big, white area with 11 golden pins around. In left, top corner, there is "RF1" mark - that (i hope) points to "radio module":
Image

Maybe, somebody can recognise a module which can fit there?

And just out of curiosity - any ideas of that chip:
Image
It's "U3" on the same PCB, just below white area. Package QFN10.
Attachments
i2c_power_up.zip
(25.66 KiB) Downloaded 678 times
gopropit
 
Posts: 30
Joined: Sat Dec 11, 2010 4:32 pm

Re: the GoPro Hero HD "bus" interface

Postby gopropit » Wed Jan 12, 2011 3:01 am

janmartin wrote:
I guess its time for you to update to the new firmware, then see if the shutter release pin can be found?

JanMartin


Hi Jan

I don't like to update the firmware untill I have old one in the file format "bin", same as new one. In that case, I'll be able to swap from old to new and back in order to compare quality and functions of the camera. If anybody heard about dump of old firmware, please let me know.
gopropit
 
Posts: 30
Joined: Sat Dec 11, 2010 4:32 pm

Re: the GoPro Hero HD "bus" interface

Postby Xtreemtec » Wed Jan 12, 2011 4:37 am

I don't have mine yet to thinker with..
But surely will look into the ' audio input'

So if the ADAPTER goes down after power down you can use this to connect a led with resistor on it to have feedback. Use one button mode and use the power / mode input to put the unit on and off..

Intresting so far.

Could somebody get a hold on that Ambrella document ?? I'm not able to safe it but it is very nice docu for reference. Looks like on that unit the line input is not wired. So i have to do some reverse engineering on the GoPro to see if i need to buffer / add some resistors / caps on the line in from not killing / or overreacting it.

Still waiting for my GoPro. iPhone cable standing by..
Xtreemtec
 
Posts: 12
Joined: Mon Jan 10, 2011 12:38 am

Re: the GoPro Hero HD "bus" interface

Postby gopropit » Wed Jan 12, 2011 5:04 am

Xtreemtec wrote:
So if the ADAPTER goes down after power down you can use this to connect a led with resistor on it to have feedback. Use one button mode and use the power / mode input to put the unit on and off..



Hi Xtreemtec

As a simple indication of the device's on/off state - this should work without problem.

Looks like on that unit the line input is not wired. So i have to do some reverse engineering on the GoPro to see if i need to buffer / add some resistors / caps on the line in from not killing / or overreacting it.


On our camera, both inputs are wired through capacitors C124 and C125 (both 100nF). As far as I remember, I checked that some time ago.
Image
Of course is better if you'll check that and confirm.
gopropit
 
Posts: 30
Joined: Sat Dec 11, 2010 4:32 pm

PreviousNext

Return to Old Forum Topics - Tips, Tricks and DIY Customizations - ALL Models

Who is online

Users browsing this forum: No registered users and 0 guests

suspicion-preferred