Breakout Cable For Prototyping

[johnjtaylor]

Hi all,
This is my first post here - I've been watching the progress of the project for months, got my order in and now I'm anticipating the arrival just like everyone else.

I'm a hardware hacker at heart and am really looking forward to poking around with all the i/o signals that are exposed in our little box of tricks. To get us started we are going to need a breakout cable to expose the signals on the A/V connector. I'm not sure if the dev team are looking at making one available, but if not then we should all band together to get the best prices on things like plugs.

We should also think about designing a breakout board to attach the cable - from bitter experience I want mine to be opto-isolated wherever possible (got to keep the magic smoke inside the box!) (http://en.wikipedia.org/wiki/Magic_smoke).

Post your comments and suggestions here - lets get going and maybe we can have them ready for Pandora's arrival!

Cheers,

John

 

[jdh2550]

Thanks John - I'm in.

 

[cosam]

I don't know if I'd have all that much use for a full breakout cable, but I'd definitely like something to get at the UART(s). I'd certainly be interested in one of the plugs if anyone's planning on placing a bulk order.

 

[Hollenderster]

Consider me interested but I will have to wait for the second batch first.
I had a look at the Tyco product page for the plug. It looks like this one is considered to be molded permanently to a cable, so modding a standard TV-out cable will probably destroy it or make it at least look very ugly. Since I doubt that the TV-out cable has the UARTs and ~2V power connected, a fully patched open ended cable of about 1.5 m length seems to belong in every hackers/modders inventory. This could also be useful for any docking station/port replicator kind of application (i.e. carputer).

 

[TaG]

I had assumed they would be selling these with the Pandora and was surprised when they only offered the tv cable. I'll be interested if the price is right.

 

[MWeston]

Here's what the breakout board for devs looks like:

http://i198.photobucket.com/albums/aa99/MW...n_2007/dev1.jpg
http://i198.photobucket.com/albums/aa99/MW...n_2007/dev2.jpg

It was something throw together quickly so the devs would have access to the serial ports but I decided to add everything. S-Video looks very nice on a big TV.

 

[JerryG20]

Here's what the breakout board for devs looks like:

http://i198.photobucket.com/albums/aa99/MW...n_2007/dev1.jpg
http://i198.photobucket.com/albums/aa99/MW...n_2007/dev2.jpg

It was something throw together quickly so the devs would have access to the serial ports but I decided to add everything. S-Video looks very nice on a big TV.


Beautiful picture of the final Pandora PCB fully populated. Could we please get a nice, overhead picture of it in a blog post on openpandora.org (kind of like the 2nd blog post, just as homage to where we came from and where we are now)?

 

[WarmFluffyUK]

Excellent, are there any plans to develop the breakout board further, i.e design a case for it, and sell it as an add on?

 

[johnjtaylor]

Here's what the breakout board for devs looks like:

http://i198.photobucket.com/albums/aa99/MW...n_2007/dev1.jpg
http://i198.photobucket.com/albums/aa99/MW...n_2007/dev2.jpg

It was something throw together quickly so the devs would have access to the serial ports but I decided to add everything. S-Video looks very nice on a big TV.



That is exactly what I had in mind! Kind of obvious that you'd have already done it

I think there is definitely an option to produce the following:

(1) A connector on a small PCB to break out the pins to a header or ribbon cable

(2) The above attached to a PCB with buffering, isolation and level shifting options

(3) A fully populated PCB in a nice smart box

I'd be quite happy with (2) - though it sounds like warmfluffyuk would like (3) and stevem wants (1). I've added a poll to the thread to gauge the level of demand and then we can see where we are going.


John

 

[cosam]

I think there is definitely an option to produce the following:

(1) A connector on a small PCB to break out the pins to a header or ribbon cable
(2) The above attached to a PCB with buffering, isolation and level shifting options
(3) A fully populated PCB in a nice smart box

I'd be quite happy with (2) - though it sounds like warmfluffyuk would like (3) and stevem wants (1). I've added a poll to the thread to gauge the level of demand and then we can see where we are going.

(1) would do me fine although, if I could choose, I'd go for a cable with a moulded "Pandora-plug" at one end, with the other end either unterminated or fitted with a more easily obtainable connector.

The nice thing about your list is that if one of the more "complete" options is provided, it would be possible to provide all previous options, although it'd probably be an administrative PITA to cover all of them. If it's all kept modular enough, it would even be possible to upgrade from e.g. a cable to a bare PCB and so on.

Oh, and maybe add option 2.5: a kit with the PCB all the parts so you can solder it up yourself.

 

[Tor]

Oh, and maybe add option 2.5: a kit with the PCB all the parts so you can solder it up yourself.

I voted 3 but would be fine with 2.5 as well.

 

[emip]

2.5 and 3 are equally good from my point of view, but even just 1 would make me happy, getting hold of a distributor for the connector (in single quantity) seems to be causing some trouble.

 

[jdh2550]

Here's what the breakout board for devs looks like:

http://i198.photobucket.com/albums/aa99/MW...n_2007/dev1.jpg
http://i198.photobucket.com/albums/aa99/MW...n_2007/dev2.jpg

It was something throw together quickly so the devs would have access to the serial ports but I decided to add everything. S-Video looks very nice on a big TV.


MWeston - is it possible to get a hold of one of these boards? Pretty please?

 

[TaG]

As the work has largely been done hopefully they will consider selling them.

 

[MWeston]

MWeston - is it possible to get a hold of one of these boards? Pretty please?

I'll certainly do what I can to make sure people who want access to the extra pins on this port can do so. I don't know if it will be this board or something like it. This board uses a pricey RS-232 transceiver because it handles 1.8V signals directly from the OMAP chip but I could probably put a level shifter before the chip and use something more standard to save money when providing for the masses who need it to be cheap. This would also help get away from the fine pitched parts so anyone could solder up their own board easily if it was presented as a kit.

I haven't given any thought to a case for this board yet because it just feels like a real developers tool and not a finished product that would have much appeal to all that many people, but I could be wrong. I think the cost of a molded case would be hard to recover but maybe there is a nice hobby box at Digikey we can line the screw holes up with on a new PCB and then carve up the case to fit the connectors through.

 

[TaG]

I think the cost of a molded case would be hard to recover but maybe there is a nice hobby box at Digikey we can line the screw holes up with on a new PCB and then carve up the case to fit the connectors through.
That would seem like a sensible way to go. Nice to know it will be considered - few extra pennies into the coffers too, which is good for the overall product development.

 

[greendots]

I dont think it really needs any sort of container. The price is likely going to be more then the TV out kit so theres no reason to purchase this for non developers. Alternatively you could add some other features to this and make a full-fledged docking station (4 or 6 port usb hub for controllers and maybe tv tuner, 5.1 surround sound etc...)

 

[Chip]

Alternatively you could add some other features to this and make a full-fledged docking station (4 or 6 port usb hub for controllers and maybe tv tuner, 5.1 surround sound etc...)
And a Satellite uplink, and a flux capacitor, and a Popiel pocket fisherman, and a Fleshlight...

All you really need is access to the points on the EXT connector. If you want to add other stuff, that is your prerogative. There is no point in sending the cost of the board through the roof adding components you can get elsewhere for less.

 

[jdh2550]

All you really need is access to the points on the EXT connector. If you want to add other stuff, that is your prerogative. There is no point in sending the cost of the board through the roof adding components you can get elsewhere for less.

I agree - after all, all I really want right now is the damn plug (wires pre-attached would be a bonus!)...

Mind you I'm sure I could have fun if they did add a flux capacitor...

 

[WizardStan]

I'm not convinced that rapidly accelerating your Pandora to 88 miles per hour is a good idea.