Shop OBEX P1 Docs P2 Docs Learn Events
gps module PMB-688 not working — Parallax Forums

gps module PMB-688 not working

AlokAlok Posts: 16
edited 2010-07-14 19:18 in Propeller 1
Hello,

I have GPS module PMB-688 , before connecting to propeller chip, I decided to check it, so I connected RS-232 ( serial) module, I connected TX ping ot GPS module to TX pin of rs-232 module and RX pin of gps to RX pin of RS-232 module, I did connected vcc and gnd pin to 5v power supply, after powering up red led blinked and then became solid red, other end of RS-232 module I connected to linux host through a cable ( to see if I am receiving any character), on linux I used minicom to connect to gps module, I do not see any output from GPS module, do I have to send any string to see any output from GPS module, I also wrote a c program to send following string


$PSRF103,00,00,01,01*25\r\n

before sending above string I calculated correct checksum, but I see no output from GPS, do I have to send any another string so that GPS module starts sending NEMA sentences...?


-Thanks
Alok

Comments

  • hover1hover1 Posts: 1,929
    edited 2010-07-14 17:00
    With a solid red light, the module should start outputting NMEA data automatically. No need to send any data to get it started.

    Perhaps TX and RX are reversed on your RS-232 module? Happens a lot. Remember to set up you receiver for 4800 asynchronous bps.

    Jim

    Alok said...
    Hello,

    I have GPS module PMB-688 , before connecting to propeller chip, I decided to check it, so I connected RS-232 ( serial) module, I connected TX ping ot GPS module to TX pin of rs-232 module and RX pin of gps to RX pin of RS-232 module, I did connected vcc and gnd pin to 5v power supply, after powering up red led blinked and then became solid red, other end of RS-232 module I connected to linux host through a cable ( to see if I am receiving any character), on linux I used minicom to connect to gps module, I do not see any output from GPS module, do I have to send any string to see any output from GPS module, I also wrote a c program to send following string


    $PSRF103,00,00,01,01*25\r\n

    before sending above string I calculated correct checksum, but I see no output from GPS, do I have to send any another string so that GPS module starts sending NEMA sentences...?


    -Thanks
    Alok
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2010-07-14 18:09
    I·asked about this item a couple of weeks ago and got but one Reply.· Doesn't have the usual Parallax cornucopia of information, does it?

    Disappointing.· Parallax will move mountains for some while others get·cipher.
  • AlokAlok Posts: 16
    edited 2010-07-14 19:09
    thanks,

    yes I changed swapped TX and RX lines and it works.


    -Alok
  • hover1hover1 Posts: 1,929
    edited 2010-07-14 19:16
    PJ, I agree. Very little information short of plugging in and hope you get something. I did notice that they did add this:

    ·http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/PULSTAR_NMEA_commands.pdf

    So now tech support will get deluged with questions on programing the GPS for different outputs, I don't think they are ready for it. I'll just have to get some of the new ones and dive into it for myself.

    Jim

    PS This should be moved to the Sensor Forum
    PJ Allen said...
    I asked about this item a couple of weeks ago and got but one Reply. Doesn't have the usual Parallax cornucopia of information, does it?

    Disappointing. Parallax will move mountains for some while others get cipher.
    Post Edited (hover1) : 7/14/2010 7:22:15 PM GMT
  • hover1hover1 Posts: 1,929
    edited 2010-07-14 19:18
    Glad it's working!

    Jim
    Alok said...
    thanks,

    yes I changed swapped TX and RX lines and it works.


    -Alok
Sign In or Register to comment.