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GPS to Propeller Interface — Parallax Forums

GPS to Propeller Interface

MJG300MJG300 Posts: 3
edited 2013-10-12 11:04 in Propeller 1
Hello Everyone,

First off, I am a noob to the propeller chip. Alot of experience with BS2px but crawling through the Propeller Manual.

I like to interface various devices to micro controllers. I am going to try the good ole' GPS to the Propeller trick. I have seen the Full Duplex code, but I get confused at the assembly language. (I don't want to use code unless I fully understand it.) I am going directly to the GPS Module at 38,400 baud rate. My goal is to communicate fully using the NMEA 0183 standard, written totally in SPIN Language. In addition to the prop manual, I also have the "Programming and Customizing the Multicore Propeller Microcontroller" Book.

Any help in pointing me in the right direction would be very helpful.:thumb:


Thanks to All,
Mark

Comments

  • dgatelydgately Posts: 1,630
    edited 2013-10-11 19:51
    Did you check out this?

    http://learn.parallax.com/KickStart/28500


    dgately
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-10-11 19:52
    MJG300 wrote: »
    (I don't want to use code unless I fully understand it.) I am going directly to the GPS Module at 38,400 baud rate. My goal is to communicate fully using the NMEA 0183 standard, written totally in SPIN Language.

    Spin isn't fast enough to use 38,400 bps.
    Where you willing to use Serin and Serout without understanding what the Basic Stamp was doing behind the scenes? If so then you ought to trust the various methods of a serial object even if you don't fully understand the code.

    If your GPS uses 5V logic use a 10k resistor on the Propeller's receiving pin.
  • HughHugh Posts: 362
    edited 2013-10-12 10:43
    I grabbed NMEA 0183 data from GPS at 4,800 bps using SPIN and letting FullDuplexSerial* do the legwork ('encapsulation' is A Good Thing). Not sure whether it would work at 38,400 bps. Post/code is here. Hope this helps...

    :smile:

    * I think FullDuplexSerialExtended worked more reliably in the end.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-10-12 11:04
    Hugh wrote: »
    I grabbed NMEA 0183 data from GPS at 4,800 bps using SPIN and letting FullDuplexSerial* do the legwork ('encapsulation' is A Good Thing). Not sure whether it would work at 38,400 bps

    Hugh, I think your code would work fine at 38,400 bps. When I said Spin isn't fast enough to work at 38,400 bps, I meant if the serial driver were written in Spin. Your project uses a serial driver with a PASM section. The PASM section takes care of reading and sending the bits.

    There is a serial driver written in Spin. IIRC, it's call SimpleSerial. Since it's written in Spin, it's limited to slow rates. I think it can communicate at 9,600 bps but not much faster.
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