Ext Port And Rs232

[sixtyfifthbit]

When I ordered my Pandora, I asked about getting a couple of EXT port connectors, so I can make an RS232 adapter for a project I had. The reply was that OpenPandora wasn't selling them at the moment. I tried to find out if the EXT port was using an existing "off the shelf" port so I could buy the connectors elsewhere, but neither Openpandora nor the wiki had that information. Can someone in the know fill in that info, and possibly point to a source for connectors?

 

[cbox]

I've been trying to find it, it's been linked to on the board long, long ago, but search isn't coming up with much. As far as I remember though, the companies that sold the part all require minimum orders in the thousands, so it probably won't be easy to get (unless you want a bunch). I believe gbax will have extras in stock, though.

Also, I believe that the ext port doesn't have RS232, probably easier to use a USB > RS232 adapter anyway. There are internal solder pads for RS232.

 

[DragonAX]

What would be great is if the TV out cable actually had conductors connected to all of the pins in the EXT connector so we could just buy a TV out cable and chop the end off. It'd be easier than soldering one up yourself too.
I guess it's a bit late for that thought though...

 

[Exophase]

Also, I believe that the ext port doesn't have RS232, probably easier to use a USB > RS232 adapter anyway. There are internal solder pads for RS232.

Two UARTs are brought out to the ext port. There's no RS232 transceiver on the board, as that'd be a pretty obvious waste of money and board space for something almost no one wants.

Connector cables brought out the UARTs to dev breakout boards. MWeston has said they may even make some more BoBs to sell. I'm sure the connector isn't custom-made and can be found in something somewhere.

 

[droneb]

IIRC

OPT bought 20k just in case. (or was it the 10k each male female)


those boys are sure hard to find, but i believe they are also hard to solder.

 

[DragonAX]

Hrmmm if it's gonna be too tricky I might start thinking about ripping it off and replacing it with a mini IDC header (I'm pretty sure they exist). Dunno if it'd fit or not...

 

[BackAssward]

MWeston did say at one point that he would get extra EXT connectors so people could do customizations. If that is still true, I cannot say. The part is off-the-shelf, but the site we had doesn't seem to have them in stock. I found my post from this thread that has the relevant info (the post is very old, we would need an update from MWeston if he still plans to buy extra connectors):

According to a couple threads, this is the connector you are looking for, but good luck trying to find any. Though, MWeston did say over a year ago:

...
I'll try to have lots of extras on hand for people who want to build their own add ons....

 

[Zotty]

Would love to be able to buy a BoB. Somehow (TTL) UART's always seem to pop into my life when all I got is hardware that lacks a easy to use port.

This will probably looked at once the 1st batch (the 4k one that is) is done. *fingers crossed*

 

[torpor]

I am sort of having the opinion that if there are 10,000 EXT connectors out there under someones control, then the Pandora should ship with one or two in the box.

 

[Exophase]

I am sort of having the opinion that if there are 10,000 EXT connectors out there under someones control, then the Pandora should ship with one or two in the box.

Add a part to the packaging procedure that very few people want, most would lose, and probably even be confused as to why it's there... and give away hundreds, maybe thousands of dollars of merchandise for free.. Parts that possibly can't be easily replaced and are probably reserved for cables made in the future.

No, including them in the box seems like a bad idea to me. Probably should just sell them on request to the couple dozen or so who want them. Or they could just buy TV out cables.

 

[sixtyfifthbit]

I am sort of having the opinion that if there are 10,000 EXT connectors out there under someones control, then the Pandora should ship with one or two in the box.

Add a part to the packaging procedure that very few people want, most would lose, and probably even be confused as to why it's there... and give away hundreds, maybe thousands of dollars of merchandise for free.. Parts that possibly can't be easily replaced and are probably reserved for cables made in the future.

No, including them in the box seems like a bad idea to me. Probably should just sell them on request to the couple dozen or so who want them. Or they could just buy TV out cables.

AS much as I would like one, I must agree. I was willing to pay extra for mine. Hopefully, if OP has extras, they will be selling soon.

Also, I guess I meant UARTs, not necessarily RS232 voltages. What I want runs with TTL voltages anyway - it should be a direct connect, hopefully.

 

[Zotty]

Oh crap, just blew a RS232 port in a one of a kind device.... *snif*

I hate RS232 transceivers...

 

[urjaman]

Also, I guess I meant UARTs, not necessarily RS232 voltages. What I want runs with TTL voltages anyway - it should be a direct connect, hopefully.

Unless you want to connect pandora to some MCU that has 1.8V IO voltages*, you'll still need to level convert them. Still, its just a single chip.

*:
OMAPs
Atmel XMegas at 1.8V (12Mhz)
Propably other ARM SOCs, i dunno.

But actually, theres not a lot of hobby class stuff that runs at 1.8V.

EDIT: Oh and I would pay to get one or two of these connectors included in the box. AND if there is just a dozen of people who want this, I think that it wouldnt be too much to ask (not many packages to special-case), if they already have the connectors.

 

[Zotty]

Did anyone bother to ask OPT yet?

 

[mitosis]

I always figured that I would just wire up a MAX232 chip somewhere... I remember looking at some datasheets for the 3530 a while back and seeing a spot where it could go.

I don't really remember anymore but I'll look into it more once I have my pandora in hand. I was thinking of adding the rs-232 conversion hardware internally to the pandora and cutting an extra hole for some kind of mini 9 pin connector, then use an adaptor cable to turn that into DB-9 for my com port.

I GUESS a usb to rs-232 cable could be used, but those never work right for me so meh.

 

[hunternet93]

For a great USB > serial adapter, try one of these: http://www.sparkfun.com/commerce/product_info.php?products_id=9115 I have one for serial communications is ATmegas, and it works perfectly. Sparkfun also has a board that brings out just about every serial-related pin imaginable. I've used these under Linux with no problems whatsoever, just plug and play (on /dev/ttyUSB0).

 

[Exophase]

For a great USB > serial adapter, try one of these: http://www.sparkfun....roducts_id=9115 I have one for serial communications is ATmegas, and it works perfectly. Sparkfun also has a board that brings out just about every serial-related pin imaginable. I've used these under Linux with no problems whatsoever, just plug and play (on /dev/ttyUSB0).

This adapter is 5V/3.3V, you probably need 1.8V for the Pandora.

 

[peca]

Exophase: I guess that he meant use it opposite way - connect USB side to USB on Pandora and use serial side as RS232, instead of breaking RS232 from EXT port. I think that use EXT port and some level shifter will be better - just guess, not electronics engineer

 

[Exophase]

Exophase: I guess that he meant use it opposite way - connect USB side to USB on Pandora and use serial side as RS232, instead of breaking RS232 from EXT port. I think that use EXT port and some level shifter will be better - just guess, not electronics engineer

That adapter isn't RS232, it's 5V TTL levels. USB to RS232 cables, on the other hand, are very common. It's also the method that makes the most sense to me, unless people are this dead set against using Linux.

 

[urjaman]

That adapter isn't RS232, it's 5V TTL levels. USB to RS232 cables, on the other hand, are very common. It's also the method that makes the most sense to me, unless people are this dead set against using Linux.

That adapter is great for easy interface for what not hobby uC projects. Still, for some purposes a real UART wins over USB converter because if you do ping-pong-style communication over RS232-USB, then the latency of USB will be a major slowdown (Get the idea: doing SPI programming of an AVR uC with an FT232RL chip (using ft232rl pins as gpio) happens at a breakneck speed of 3 bytes/s ....). Latency of a real UART is near zero (when compared to USB latency) (interrupt latency + inthandler).
I might fancy a "dongle" for the Pandora that makes the UART with flow control a real RS232-level UART with the normal connector and adds a header for the second uart at a input-able TTL-level (and some power); 5 pin header would do: gnd,rx,tx,vcc-in,2.8V.