GPS Guided Robot

fawazalm · February 24, 2016, 11:16am

Hey,

I’m following the tutorial here (http://www.dexterindustries.com/GoPiGo/projects/python-examples-for-the-raspberry-pi/example-project-a-raspberry-pi-gps-guided-robot-with-the-gopigo/).
I have the Grove GPS installed. However, after running the python script, i’m unable to capture data.
Do I have to cross the wires like they mentioned in the tutorial?

karan · February 24, 2016, 11:28pm

Hi fawazalm,
Yeah, you would have to cross the wires to make it work.

-Karan

fawazalm · February 25, 2016, 1:25am

Hello Karan,

Even though I crossed the wires, I still couldn’t capture data.
Any ideas of what the problem may be?

JohnC · February 25, 2016, 1:30am

If we backup, what version of the GoPiGo are you using?

fawazalm · February 25, 2016, 1:52am

I’m using the latest versions of the GoPiGo and the Grove GPS module.

JohnC · February 25, 2016, 1:58am

This should not require a switching of the lines. On the GPG2 the lines are not reversed for serial I think. Just to confirm, your GPG came with a velcro strap for the battery pack, right?

fawazalm · February 25, 2016, 2:07am

Yes. Even when I don’t switch the lines it still wouldn’t work. Could the problem be software related?

JohnC · February 25, 2016, 2:11am

Do you have a logic analyzer avalable to check the lines? What I would like to do is check the serial data back and forth on the serial line and make sure that the GPS module is working.

fawazalm · February 25, 2016, 2:19am

No, unfortunately I don’t have one. Is there any other way to check if the GPS module is working?

JohnC · February 25, 2016, 3:53am

Let me give it a shot, I am working on a project with these parts at the moment.

JohnC · February 25, 2016, 5:07am

Can you try this code to test if your GPS sensor is working:

github.com

DexterInd/GoPiGo/blob/master/Software/Python/Examples/GPS_Bot/gps_hardware_test.py

#!/usr/bin/env python
########################################################################                                                                  
# This example is for is the simplest GPS Script.  It simply reads the
# raw output of the GPS sensor on the GoPiGo or GrovePi and prints it.  
#
# http://www.dexterindustries.com/GoPiGo/ 
# http://www.dexterindustries.com/GrovePi/                                                                
# History
# ------------------------------------------------
# Author     Date      		Comments
# John      2/25/2015		Initial Authoring
# 			                                                         
# These files have been made available online through a Creative Commons Attribution-ShareAlike 3.0  license.
# (http://creativecommons.org/licenses/by-sa/3.0/)           
#
########################################################################


from gopigo import *
import serial, time

This file has been truncated. show original

What’s the output? Do you get a full GPRMC string out?

fawazalm · February 25, 2016, 5:42am

Hello John,

Yes, I got the a similar output.

$GPGGA,000047.799,0,0,M,M,*4C

$GPGSA,A,1,*1E

$GPGSV,1,1,00*79

$GPRMC,000047.799,V,0.00,0.00,060180,N*46

$GPGGA,000048.799,0,0,M,M,*43

$GPGSA,A,1,*1E

$GPGSV,1,1,00*79

$GPRMC,000048.799,V,0.00,0.00,060180,N*49

$GPGGA,000049.799,0,0,M,M,*42

$GPGSA,A,1,*1E

$GPGSV,1,1,00*79

JohnC · February 26, 2016, 3:36am

Great, that means your sensor is working. That’s great news! You may need to add a 0.001 or 0.01 delay before the serial read of the GPS to make the other program work though.

fawazalm · February 26, 2016, 8:25am

YES, IT WORKED!
Thank you so much for your help!

JohnC · February 28, 2016, 6:07am

Good deal. Did you make any changes to the files? Would you mind making a pull request if you did?