Ultimate GPS Breakout not accepting commands

[mauimart]

My Ultimate GPS Breakout unit is also unresponsive to configuration commands. I am trying to change the update rate from 1Hz to 5Hz using the adafruit "echo" code with no success.

GPS.sendCommand(PMTK_SET_NMEA_UPDATE_5HZ);

The unit is also unresponsive to commands telling it which sentences to put out. I have scoped the RX pin (pin 10) on the gps chip to make sure it is receiving the commands at power up and the serial data looks good. It seems no matter which commands I change, the gps defaults to 1Hz, 9600 baud, and all sentences.

Here is some sample output for "GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);" and "GPS.sendCommand(PMTK_SET_NMEA_UPDATE_5HZ);".
From what I can gather in the PMTK command packet spec the "2" in $PMTK001,220,2*31 means ‘2’ = Valid command / packet, but action failed .

The actual data when the unit has satellite lock is accurate. Any ideas? Is this a bad unit?

Thanks.
Martin



Adafruit GPS library basic test!
$PMTK001,220,2*31
$GPGGA,003126.067,,,,,0,0,,,M,,M,,*4F
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,003126.067,V,,,,,0.00,0.00,060180,,,N*45
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,003127.067,,,,,0,0,,,M,,M,,*4E
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,003127.067,V,,,,,0.00,0.00,060180,,,N*44
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,003128.067,,,,,0,0,,,M,,M,,*41
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,1,1,00*79
$GPRMC,003128.067,V,,,,,0.00,0.00,060180,,,N*4B
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32

[adafruit_support_rick]

Please post a photo of your wiring and soldering.

[8bar]

I, too, am having the problems that these two people report--gps.sendCommand does nothing. I get the same output that is shown above (all sentences), and my connections and soldering look just like the photos. I haven't used the MT3339 GPS PC Tool software. I'm using the basic echo sketch and simply changing the commenting:

Code: Select all

  // You can adjust which sentences to have the module emit, below
 
  // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
  //GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
  // uncomment this line to turn on only the "minimum recommended" data for high update rates!
  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY);
  // uncomment this line to turn on all the available data - for 9600 baud you'll want 1 Hz rate
  //GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_ALLDATA);

Has there been any resolution of this issue?

[adafruit_support_rick]

Sounds like you are receiving data from the unit but it's not receiving data from you. Check your connection to GPS RX. Try different jumper wires, different breadboard slots, etc. Check the soldering on the GPS RX pin - reflow it.
Feel free to post a picture of your wiring and soldering.

[8bar]

I think I fixed the problem. I put a 1 sec delay after GPS.begin and after each GPS.sendCommand and now it works.

[adafruit]

Sounds like it needs a little more 'boot' time?

[adafruit_support_rick]

I think I fixed the problem. I put a 1 sec delay after GPS.begin and after each GPS.sendCommand and now it works.

Weird. What kind of arduino are you using? Do you need the delay after every sendCommand? Can you see if it works if the delay is only before and/or after the GPS.begin?

[8bar]

OK, I took out the delays after the sendCommands. It didn't work the first time I tried (I asked for RMC and GGA but got RMC only).

But after that, it worked every time, and I could switch between

GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA),
GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY), and
GPS.sendCommand("$PMTK314,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29") (GGA only)

arbitrarily with the correct output showing up.

Then I took the delay out after the GPS.begin, and I could no longer switch again.

[adafruit_support_rick]

Then I took the delay out after the GPS.begin, and I could no longer switch again.

OK - that makes some sense, I suppose. GPS.begin sends a baud-rate command, so maybe your GPS is not quite finished with that when the next command comes in.

Some questions:
Are you calling GPS.begin(9600), or are you setting some other baud rate?

Are you using hardware or software serial?

[8bar]

Are you calling GPS.begin(9600)

yes

Are you using hardware or software serial?

software

[adafruit_support_rick]

Thanks. Looks like we'll have to update the library to include a delay.

[adafruit_support_rick]

Hi - We've updated the library to add a delay after GPS.begin. If you get a chance, download it and see if it works for you.
Thanks!

[spade]

Just received my Ultimate GPS breakout & was experiencing the same thing using your newest code. After fussing with it and even re-soldering the Rx pin as someone suggested, I realized that the Serial.println("Adafruit GPS library basic test!"); was never even printing. So I changed
//Serial.begin(115200); to
//Serial.begin(9600); and now its working.

Maybe you can tell me why this worked but I figured it has something to do with the delay in trying to read&write.

(Note that around 14400 is where it starts to get jittery.)
Best,

[8bar]

You also need to change the speed of the serial monitor to 115200. Do that in the lower right-hand corner of the monitor. It is 9600 by default, which explains why it worked when you changed your code.

[8bar]

Hi - We've updated the library to add a delay after GPS.begin. If you get a chance, download it and see if it works for you.
Thanks!

Yes, the new code with the delay works well! Thanks.