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gps shield on serial arduino
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gps shield on serial arduino

by blue-water on Fri Aug 01, 2008 10:28 pm

Hi,

I've got some problems with the gps shield on the latest version of the arduinoboard serial single (s3v3 2008). I am using arduino ver10 since ver 11 is buggy with the software from the Lady.

Apparantly I do not get the output of the gps as written in the first tutorial (connect, option 2).

Any Idea why?

Second problem: I do not get the sd card working. The error is 'cant't open filesys'. Is this related to the NG problem? Should I change R6 and R10 to zero and 2k ohm respectively?


The strange thing is that GPSTest_RMC is working.

I have the feeling that there is a problem with the rs232 level output of the gps being interfaced to my computer (using two very different rs232 ports (usb-rs232 cable and internal pci port)). I'm not sure what to do.


Does someone have any idea what is going on?

Thanks,

Nick
blue-water
 
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Update

by blue-water on Sat Aug 02, 2008 9:19 am

Update,

Just checked. The serial output levels of the EM-406A gps board is 3.00V.
Is this enough to drive the rs232 converter in the S3v3 rev 2 serial arduino board? Humm...
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by blue-water on Sat Aug 02, 2008 11:54 am

So I hooked up a maxim rs232 chip to the ftdi connector. Finally I get some useful data out the gps. :D

Note: Do not install the rs232 jumper on the serial arduino board, since it interferes with the output. Humm... :?:
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by blue-water on Sat Aug 02, 2008 7:58 pm

Another update.

Still playing with the gps in direct mode. I played with the sirfdemo 3.87.

I could for some reason not switch back to the nmea protocol. It took me an hour to figure out that the rsr232 port of my computer is not having a proper relation with the maxim chip (or gps for that matter). Using a different serial solution solved it (using an usb <->rs232 cable). I still do not understand this. This problem was also reported on another website (gpspassion). Hardware Sirfstar bug?

Warning: do not press 'Switch to user 1 protocol' It will kill the gps instantaneously. Well, I did not know that, so it stopped working :(

Solution: Open the small bottom shield ( :evil: ) then open the top one (with the patch antenna). Then desolder the small antenna pin and you can open the top/antenna. Desolder the battery, wait a bit. Test it. When it works again in nmea, reverse all steps. It took me about 1.5 h.

have fun!

ps. Anyone an update on the sd card problem? I'm still waiting for a solution...
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by adafruit on Sun Aug 03, 2008 12:56 pm

so i dont have a serial arduino, theres no way to test it but in theory it should work just fine. sirfdemo software is a bit finicky.
perhaps make sure that theres data going both ways (use a scope)

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by blue-water on Sun Aug 03, 2008 3:10 pm

Hi Lady,

I changed R10 to 2K and jumpered R6. It still did not accept the 128 Mb 'Dane Elec' sd card. Then I plugged a 2GB Intuix sd card into the slot. That one works. But this is hardly convenient. I would like to use my cheap, spare card.

Q? Should I revert to the original resistors?

Q? Why does this schematic behaves so strange? Others reported the same.

Q? Why is there no 100nF cap accros Vcc and Gnd close to the sd cardholder?
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by adafruit on Mon Aug 04, 2008 1:23 am

1. well if it works, stick with it?
2. the NG has a 'bug' in it that requires changing the resistor values. NGs are no longer sold so this isnt really a huge deal
3. isn't necessary

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gps shield card problem.

by dincer on Tue Aug 05, 2008 2:41 pm

i had the same problem 'cant open filesys' when i first operated my shield with a spare 32mb sd card on my decimilia. then i tried a 256 mb kingston sd and the result was the same. the problem wanished when i placed my 1gb sd of my camera into slot. i think these gps shields donot like the old spare cards... :) stick with your working card and there will be no problem i guess...
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Please be positive and constructive with your questions and comments.