GPS from Polstar

[billduck]

I had successfully written a program for a tracking solar array - moving a set of panels to face the sun. I am switching from a real time clock to a GPS for timekeeping. So I want to read the data from a Polstar unit <http://www.polstargps.com/Polstar_GPSpr ... MB648.html> I have a hunch that the stock code for a GPS has not been written for this particular GPS. Has anyone modified the stock code for this particular GPS? I apologize, I am a novice code writer.Thanks in advance. Bill S

[JohnCrow]

Hi Bill

Have you any reason for using this GPS module. Flowcode may be easier to get working with the fastrax one as used in the Matrix eblock
See these posts for more info on problems encountered. I see from the website it is capable of runing at 9600 baud which is the flowcode macro default so thats a good start

http://www.matrixmultimedia.com/mmforum ... gps#p34862

I personally have only used the eblock gps, but it does work very well even indoors way from windows.
This sounds like an interesting project.

[billduck]

Duh!. I will explore that.

[billduck]

So, I am using a ATMEGA2560 processor. I note that MM has several upstream boards, including an AVR board. I hope that the packaged code, that comes stock in Flowcode4, has been written for this board?
Is this a legitimate question? Am I on the right track by incorporating a Fastrax GPS?
I am an ex-non-programmer, but very timid about that.

[JohnCrow]

Hi Bill

Im not familiar with the AVR chips but I'm sure flowcode 4 has the gps for all the different versions. Im sure MM will confirm this when they open today.

[Benj]

Hello,

Flowcode v4 for AVR supports the ATMEGA2560 and the GPS component (though it is the older 4800 baud version of the component).

Flowcode v5 for AVR should be ready for release within the next couple of months which supports the newer GPS component and all the other v5 upgrades.

The ATMEGA2560 device will not work with the EB019 upstream board as this only supports DIL type IC packages. See the EB019 datasheet for a list of compatible target AVR devices.

[billduck]

Put me on the list for Flowcode v5-AVR.
It seems logical to ask where do I connect the data line to the Atmega2560 microcontroller. I have looked at the custom code for the GPS, and do not recognize anything that shows where to connect. The help file indicates to use the hardware UART. I find 4 TxRx (D0-D3).
Thanks, from a newbie.

[Benj]

Hello,

It looks like the standard UART signals are attached to the following pins on this device.

RXD0 -> E0
TXD0 -> E1

RXD1 -> D2
TXD1 -> D3

RXD2 -> H0
TXD2 -> H1

RXD3 -> J0
TXD3 -> J1

By default the component will use UART channel 0.

[billduck]

I finally got around to hooking up the GPS from Parallax <http://www.parallax.com/Portals/0/Downl ... n_V0.1.pdf> It works fine on the Latitude,Longitude and Time, all being reported correctly. But the date comes in a (my formatting) D/M/Y as 0/93/0. The date today is 6/13/2012. I would expect the numbers to be reported as 06,13,12. I have attached subroutines for the time and date. Any Ideas? If I reboot the mC, the number changes. For instance, now it is 72/0/3.
By the way, I have not figured out how to give thanks for the help the forum provides.

[JohnCrow]

Hi Bill

By the way, I have not figured out how to give thanks for the help the forum provides.

Just click the little "Thumbs Up" Icon on the top right of the message window

[Gary Freegard]

Hi Bill

Not sure if this could help you, but I did modify the GPS example to help Jorgen
http://www.matrixmultimedia.com/mmforum ... =29&t=9141

But also if you know the GPS format you can check to see if the Flowcode GPS module is looking at the right part, by having a look at GPS_Process_String in the Custom Code section.

Hope this helps.

Gary

[billduck]

If I start a project with a GPS component, and ask to "read Longitude", and compile to hex, the 4 errors reported are:
undefined reference to float32_div
undefined reference to float32_from_int32
undefined reference to float32_add
undefined reference to float32_sub

Flowcode 5 for AVR.
Thanks, Bill S

[Benj]

Hi Bill,

I have just tried it here and it is working ok for me. Can you please attach a program that demonstrates this compilation error?

[billduck]

I created and added the file. The error occurs when I compile to hex.
I still have FC4 Pro installed.
Thanks.