SparkFun Forums

[donzi]

Hi All,

Rant on
I received LS23060 GPS Receiver instead of the 32 Channel LS20031 GPS 5Hz Receiver I ordered.
They say it is the LS20031 GPS 5Hz Receiver I ordered event though the pictures I sent them show something different. Twice in one month I have not recieved what I ordered from this company.
Off Rant

Problem,
I can't get the reciever to send clear text showing the NMEA data being sent to RealTerm.
Tried different baud rate settings both on the PC and on the GPS. Nothing seems to be working.
I have attached an image of what I'm seeing in the RealTerm window.

realterm_error.jpg

Anyone have any ideas what I can do to fix this issue?

Thanks
Don Anderson

[teekay_tk]

initial impressions... looks like a bad ground connection between PC and GPS.. can ou check there are no dry joints, broken wires etc

[Polux rsv]

Yes, bad connection: ground connection, level converter problem. See bottom of your display: UART receiver framing error.

Or the classic :
-Hey, I connected my GPS unit directly to the RS232 port, and it doesn't work !!!
-How do you connect it ?
- As usual, GND on GND, Tx on unit to RS232 Rx, and Rx to Tx
- And what about a level converter, or usb to TTL serial ?
- What are you talking about ?
- You can't connect directly a device with TTL level outputs to a RS232 interface.
- And how can I make it working ?
- Use a simple MAX232. Or connect your GPS to a USB to TTL serial cable
- Ok, I will try this. Thanks
- Ok, who's next ?

Ok, Ok, dont't push me, I see the exit, I could go by myself

Angelo

[teekay_tk]

I guess if he was not using level converter he would not see any data all because UART output is inverted in polarity as RS232.

[donzi]

Hey All,
Thanks for the quick replys.
It turns out there is a issue with the FTDI cable I was using that was part of the problem.

Anyone have an idea on a way to configure the GPS so I do not get a CRLF at the end of each line?

RealTerm_error2.jpg

Thanks for any help you can provide.
Don Anderson

[Polux rsv]

I think you can't setup. But receiving CR/LF will simplfy your serial input code. You can then remove them by software.

Angelo

[teekay_tk]

or you can have a microcontroller in between just doing that, i.e, removing th Cr Lf
but my question is Why?

[donzi]

Good point.
The CrLF would be a good marker to show the end of one set of values.
Was not thinking of that. Just thinking of the microcontroller not having to deal with processing the extra charecters. The microcontroller will be comunicating with another microcontroller and at some
point I plann to have main controller recording data from 12 or more sensors.
Thanks for helping me open my sights

[e-samolocik]

Hi All,

Just couple of days ago, mistakenly I have inverted Ground and Power cables and connected my Locosys LS20031 gps.
In resoult something burned. It doesn't power up anymore.
Does anyone know if this can be fixed?

Is there any resistor that i can exchange and bring my GPS back to life?

I would be thankful for any help.