Why does this cable work???

MadScientist · 12-11-2012, 07:02 PM

I am giving my old Canon camera to my son. He still has an old 27" CRT TV, that has composite but no HDMI connections. The camera came with a stereo AV cable that has a mini HDMI connector on one end and RCA composite; 2 stereo audio, 1 video, connectors on the other. http://www.adorama.com/ICAAVCDC400S.html

I nor he has tried it out yet, but since it came with the camera I'm assuming it works. But without a DAC how????

sdifox · 12-11-2012, 08:07 PM

err, I doubt it is a hdmi end.

Zorander · 12-11-2012, 08:48 PM

Doubt the camera sends out a digital signal (HDMI). It's probably sending out analog signals (composite) out of the mini-HDMI plug to the composite RCA ends. There are more than enough pins in the mini-HDMI plug to accomodate a composite video+audio signal.

Matt1970 · 12-11-2012, 11:30 PM

Quote:

Originally Posted by Zorander

Doubt the camera sends out a digital signal (HDMI). It's probably sending out analog signals (composite) out of the mini-HDMI plug to the composite RCA ends. There are more than enough pins in the mini-HDMI plug to accomodate a composite video+audio signal.

It's more than likely this.

MadScientist · 12-12-2012, 06:46 AM

Quote:

Originally Posted by Zorander

Doubt the camera sends out a digital signal (HDMI). It's probably sending out analog signals (composite) out of the mini-HDMI plug to the composite RCA ends. There are more than enough pins in the mini-HDMI plug to accomodate a composite video+audio signal.

This was my first thought, but there is also an optional cable you can use, a mini HDMI to an HDMI to hook the camera up from the same port on the camera to an HD TV. See page 38 of manual http://gdlp01.c-wss.com/gds/7/030000...0HS_CUG_EN.pdf

http://www.bhphotovideo.com/c/product/516706-REG/Canon_2384B001_HTC_100_HDMI_Male_to.html

Of course you can get this same cable from Monoprice for $3.20.

So does the camera put out an analog signal when the composite cable is hooked up and then somehow switch to a digital signal when the HDMI cable is hooked up???

Zorander · 12-12-2012, 07:10 AM

I'm no expert on this but my next guess is the camera can detect if it is connected to a HDMI-capable or analog-only device (by checking for an open/closed circuit on one of its pin pairs, for example).

MadScientist · 12-12-2012, 07:57 AM

Quote:

Originally Posted by Zorander

I'm no expert on this but my next guess is the camera can detect if it is connected to a HDMI-capable or analog-only device (by checking for an open/closed circuit on one of its pin pairs, for example).

This sounds plausible. It has to be the camera detecting which signal to put out. You can not do it with just a cable; as these unhappy, scammed, customers at Amazon will attest to. http://www.amazon.com/HDMI-RCA-VGA-Cable-1-8m/dp/B002ZUI68G/ref=pd_sim_e_7

Railgun · 12-12-2012, 08:24 AM

That`s not mini HDMI. That`s a mini USB connection.

MadScientist · 12-12-2012, 09:12 AM

Quote:

Originally Posted by Railgun

That`s not mini HDMI. That`s a mini USB connection.

Are you referring to this cable: http://www.bhphotovideo.com/c/product/516706-REG

The description states it's a "HDMI Male to Mini HDMI Male Cable".

Railgun · 12-12-2012, 09:25 AM

I'm referring to the cable you linked in the op.

MadScientist · 12-12-2012, 02:24 PM

Quote:

Originally Posted by Railgun

That`s not mini HDMI. That`s a mini USB connection.

Question answered. You are absolutely correct. I just spoke with my son who received the camera in the mail yesterday. The cable in my OP has a mini usb male connector that connects to the mini usb interface connector.

Bad assumption on my part that it was a mini HDMI.

Zorander · 12-12-2012, 09:35 PM

I found this info in this thread which you may find interesting. It does not matter whether the cable is mini-HDMI or -USB. Both have enough pins to output composite audio+video signals.

From what I gathered, all RCA plugs share one common ground, with the positive end of each of the three plugs connected on one of the pins on the other end (that's 4 pins used out of 5 available - I'm guessing the remaining pin is used for the above-mentioned detection purpose). The cable manufacturer either knows the pin layout of the device or there is a standard layout for this kind of cable.

MadScientist · 12-13-2012, 06:14 AM

Quote:

Originally Posted by Zorander

I found this info in this thread which you may find interesting. It does not matter whether the cable is mini-HDMI or -USB. Both have enough pins to output composite audio+video signals.

From what I gathered, all RCA plugs share one common ground, with the positive end of each of the three plugs connected on one of the pins on the other end (that's 4 pins used out of 5 available - I'm guessing the remaining pin is used for the above-mentioned detection purpose). The cable manufacturer either knows the pin layout of the device or there is a standard layout for this kind of cable.

Thanks for the info. My son's guess is that it's the camera's firmware that makes it possible to use the same mini USB port for the mini USB/USB cable to download pics/movies to your PC and also connect the camera to a TV with the mini USB/RCA composite cable.