How Is The Uart Going To Work?


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WhiteBat

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I've been learning about uart recently and i was wondering how to use it on the pandora. Assuming i have space, im going to put a gps and maybe 3g module in there somewhere.
For the gps i wanted to use navit of course, but does navit have like a uart input? or will it just... work? I don't really know what im tring to ask :huh:
 
I've been learning about uart recently and i was wondering how to use it on the pandora. Assuming i have space, im going to put a gps and maybe 3g module in there somewhere.
For the gps i wanted to use navit of course, but does navit have like a uart input? or will it just... work? I don't really know what im tring to ask :huh:
(Short version: use bluetooth GPS and USB 3G)

If you're speaking of modding them _into_ the pandora - i really doubt there's space for those (i doubt that for even one of them, sure not for both).
Anyways, there will be 2.8V 200mA power and 2 1.8V CMOS level UART's /dev/ttyS0 and /dev/ttyS1 on the EXT connector with one of them having flow control (RTS/CTS). I doubt your 3G module is compatible with a 1.8V CMOS level UART, or can be run from 2.8V - so even more electronics will be needed - even more likely it wont fit in the pandora.
 
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Yes - this isn't like a netbook, which is small but still has internal space; the Pandora will have practically no space for any extra boards.

And navit uses gpsd; that will talk to anything.
 
yeah, i knew about the bluetooth gps and usb 3G, but i don't really like carrying extra bricks around if i don't have to.
in short, i found room around the speakers and on the pcb itself. I'll make it fit if it kills me. ^_^

I don't mind surface mount soldering, so stealing 3.0-4-2 volts from the battery can power the module i suppose.
I thought there would be a 3.3 and 5.0 volt i could steal from the power regulator/controller but i guess not :(

thanks for the specs urjaman, maybe i should have just looked up the beagleboard specs but i don't know if the dev team had changed anything.

anyway im glad navit uses gpsd :D
if it dosent work either i will die, or go with the externals.

*edit* will the antenova M10214 work? (gps)
power voltage min: 3.3v / max: 5.5v
and the tx/rx are 1.8 volts

*edit* all 3 data sheets:
http://www.mediafire.com/?tz3kygmgfo5
 
I thought there would be a 3.3 and 5.0 volt i could steal from the power regulator/controller but i guess not :(
I only listed the abilities that are on the EXT connector (and according to MWeston free to work with as in that they dont power anything else on the pandora), ofcourse you have the 5V for the USB conn there too - and AFAIK it could be possible to take the power before the USB current limiter device (which limits to 500mA, 750mA peaks IIRC), but then you have to be careful of the amount of power you use - and a 3G modems are quite power hungry (i remember somebody saying that dont take over 100mA from the USB power (before limiter), not sure and cant find it now though). I still dont think there's space for a 3G module inside.

EDIT: The Antenova M10214 could work - i think it would be ok to power it straight from the battery (it's recommended voltage is 3.6V and it doesnt break if given 5.5V (that's all i can say sure for from the datasheets)), and there was no mentioning of the TX/RX voltages, if they are 1.8 as you say, it would be a relatively easy mod, IF you can fit it inside (battery to power, tx and rx to ext conn).
 
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Confirmed: The Pandora has GPS! j/k j/k :lol:

it seems the data sheets are different. here take a look at this one
(*edit* look at previous post)

*edit*
i think it will fit right on the pcb, where that big white dot is, im pretty sure.
(actually i think that you can put it on top of the pcb now...)
as long as i get rid of the ~2mm connector on the back and solder the wires instead.
and i can also trim the edges and make it shorter, then use epoxy, since the screw holes will be gone.

*edit 2* does anyone know the baud rate? Is it 115200, data - 8 bit, no parity, stop - 1 bit?
 
I wouldn't be very surprised, Bluetooth modules can usually communicate over UART at 921600 bps.
 
I wouldn't be very surprised, Bluetooth modules can usually communicate over UART at 921600 bps.
I've worked with a bluetooth module that could do 921600 -- but (my only experience though) with a telit 3G module that can do only 230400, but i wasnt really referring to speed but size.
 
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The Bluetooth module in Pandora can communicate at up to 4Mb/s but OMAP3 is limited to 3Mb/s with the minimum clock divider. The BT connection is limited to 3Mb/s anyway and the extra was just to minimize overheads.

If you can find a 3G module that communicates at 3Mb/s over UART, that would be your maximum link speed there.
 
well i found one that might work, but it uses half an amp of power -_-
 
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