Category Archives: GSM

Using u-Center to connect to the GPS on Raspberry Pi

u-Center from u-Blox is a graphical interface which can be used to monitor and configure all aspects of the GPS module on a BerryGPS-IMU or BerryGPS-GSM.

u-Center from uBlox
U-Center

 

u-Center only runs on Windows. It can connect over the network to a Raspberry Pi.  This will require us to redirect the serial interface on the Raspberry Pi to a network port using ser2net.

Pi Setup

Do an upt-get update and then install ser2net;

pi@raspberrypi ~ $ sudo apt-get update
pi@raspberrypi ~ $ sudo apt-get install ser2net

Edit the ser2net config file and add the serial port redirect to a network port. We will use network port 6000

pi@raspberrypi ~ $ sudo nano /etc/ser2net.conf

And add this line at the bottom;

6000:raw:600:/dev/ttyACM0:9600 NONE 1STOPBIT 8DATABITS XONXOFF LOCAL -RTSCTS

This is a breakdown of the syntax for the line above;
TCP port : connection type : timeout : serial port : serial port speed speed : serial options

you can now start ser2net using;

pi@raspberrypi ~ $ sudo ser2net

And you can use the below command to check if it is running by seeing if the port is open and assigned to the ser2net process;

pi@raspberrypi ~ $sudo netstat -ltnp | grep 6000

If it is running, you should see something similar to the output below;

check result of ser2net

Windows PC Setup and Connecting to the GPS module

You can download u-Center from here.

Once installed, open u-Center. You will get the default view as shown below.  No data will be shown as we are not connected to a GPS.

u-Center default view

The next step, is to create a new network connection and connect to the GPS which is connected to our Raspberry Pi. You can create a new connection under the Receiver and then Network connection menus.

u-Center connect to Raspberry Pi
In the new window, enter the IP address of the Raspberry Pi and specify port 6000. This is the port we configured in ser2net on the Raspberry Pi.
u-Center Raspberry Pi Address

This is what the default view looks like when connected and the GPS has a fix.u-Center connected

 

u-Center

Below I will list of the more useful windows/tools within u-Center.
You can also click on the images below for a larger version.

Data View
This window will show you the longitude, latitude, altitude and fix mode. It will also show the HDOP, which is the Horizontal Dilution of Precision.  Lower is better, anything below 1.0 means you have a good signal.

u-Center Data View
u-Center Data View

Ground Track
This window will show you where the satellites are as well as what time.

u-Center Ground Track
u-Center Ground Track

Skye View
Sky view is an excellent tool for analyzing the performance of antennas as well as the conditions of the satellite observation environment.

u-Center Sky View
u-Center Sky View

Deviation Map
This map shows the average of all previously measured positions.

u-Center Deviation Map
u-Center Deviation Map

Continue reading Using u-Center to connect to the GPS on Raspberry Pi

Control the GPIO of a Raspberry Pi using SMS from a mobile phone

In this guide we will show you how to control the GPIO pins of a Raspberry pi by send a SMS to the Raspberry Pi from a mobile phone.

 

For this guide, the GSM modem we are using to receive the SMS is the  BerryGPS-GSM.

On the software side, we will be using Gammu, which is specifically designed to control  phones and GSM modules. It also has a daemon which will monitor the GSM modem for incoming SMSs.

We will configure Gammu to trigger a python script when a new SMS is received. We will use the contents of the SMS to control what happens in Python

LEDs are used here as an example, but you can do anything you like Eg. Open a garage door, turn on some lights, etc..

 

Wiring

Raspberry PI GPIO SMS

 

We will be using the three bottom right GPIO pins on the Raspberry Pi header. These are GPIO 16, 20 and 21.
Each is connected to a different color LED as shown above. The
The resistors used are 330 Ohm  and the GND pin (shorter pin) of the LEDs is connected to the GND power rail.

 

Setup

Install Gammu and python bindings;

pi@raspberrypi ~ $ sudo apt-get update
pi@raspberrypi ~ $ sudo apt-get install gammu-smsd python-gammu

Edit the config file;

pi@raspberrypi ~ $ sudo nano /etc/gammu-smsdrc

Find the below lines and add port and speed.
For the BerryGPS-GSM, use /dev/ttyACM1 for port and at115200 for speed

port = /dev/ttyACM1
connection = at115200

At the bottom of the file, add the line below. This is the python script which will run when a new SMS is received.

RunOnReceive = sudo python /home/pi/smsReceived.py

We will do a quick test. Restart the gammu service so the new config takes effect;

pi@raspberrypi ~ $ sudo /etc/init.d/gammu-smsd restart

Send a test SMS to a mobile number. The mobile number below is an example, you will need to update this;

pi@raspberrypi ~ $ echo "This is a test from a Raspberry Pi" | /usr/bin/gammu --sendsms TEXT +614123456789

 

Python Script

This python script will run every time a new SMS is received.

pi@raspberrypi ~ $ nano ~/smsReceived.py

Copy in the below code

import RPi.GPIO as GPIO
import time
import sys
import re


RED_LED =  21
GREEN_LED =  20
BLUE_LED =  16

GPIO.setmode(GPIO.BCM)
filename=str(sys.argv[1])                               #Gammu will pass the filename of the new SMS as an argument
complete_filename="/var/spool/gammu/inbox/"+filename    #we create the full path to the file here

GPIO.setup(RED_LED , GPIO.OUT)
GPIO.setup(GREEN_LED , GPIO.OUT)
GPIO.setup(BLUE_LED , GPIO.OUT)

sms_file=open(complete_filename,"r")
#read the contents of the SMS file
message=sms_file.read(160) #note that a not-parted SMS can be maximum 160 characters

#search the contents and perform an action. Rather than use 'find',
# we will use regular expression (re) so we can ignore case.
#Most smartphones will have the first letter capitalised
if re.search('red', message, re.IGNORECASE):
        GPIO.output(RED_LED , GPIO.HIGH)
        time.sleep(2)
        GPIO.output(RED_LED , GPIO.LOW)
elif re.search('green', message, re.IGNORECASE):
        GPIO.output(GREEN_LED , GPIO.HIGH)
        time.sleep(2)
        GPIO.output(GREEN_LED , GPIO.LOW)
elif re.search('blue', message, re.IGNORECASE):
        GPIO.output(BLUE_LED , GPIO.HIGH)
        time.sleep(2)
        GPIO.output(BLUE_LED , GPIO.LOW)



GPIO.cleanup()

To troubleshoot you can view the syslog

pi@raspberrypi ~ $ tail -f /var/log/syslog

Using a button and the GPIO on a Raspberry Pi to send a SMS

In this guide we will show you how to send a SMS using a button connected to the GPIO pins of a Rasberry Pi Zero.

 

For this guide, the GSM modem we are using to send the SMS is the  BerryGPS-GSM.

On the software side, we will be using Gammu, which is specifically designed to control  phones and GSM modules.

Python will be used to monitor some buttons connected to GPIO pins and Gammu python bindings will be used to send a SMS.

Buttons are used here as an example, but you can use anything to trigger the SMS, E.g. Temperature sensor, water level sensor, light sensor, etc..

We have includes some LEDs so we can see when the buttons are pressed.

Wiring

Raspberry Pi LED button

We will be using the three bottom right GPIO pins on the Raspberry Pi header. These are GPIO 16, 20 and 21.
Each is connected to a button and different color LED as shown above. The internal pull-down resisters will be used on these GPIO.
3.3v and GND are connect to the power rails on the breadboard.
The resistors used are 330 Ohm  and the GND pin (shorter pin) of the LEDs is connected to the GND power rail.

Continue reading Using a button and the GPIO on a Raspberry Pi to send a SMS

Real-time GPS tracking with a Raspberry Pi

In this guide, we will show how to do real time tracking, use a BerryGPS-GSM and initialstate.com 

Initialstate has some great tools to easily stream data from a Raspberry Pi to Initialstate.com and show this data within a dashboard using tiles.  We will send longitude,  latitude and  speed. And use a BerryGPS-GSM to get these values and upload them via 3G.

 

You will need to create an account on Initialstate.com and then grab your access key which can be found under "My Settings"

BerryGPS-GSM setup

If you are using a BerryGPS-GSM, you can follow this guide to get the GPS working and get your Pi to connect to via 3G using PPP.

The above guide also shows how to make your Pi connect to the carrier network automatically when booted. You will need this if you plan to perform remote tracking(E.g. Asset tracking).

Install required libraries

pi@raspberrypi ~ $ sudo apt-get install python-pip
pi@raspberrypi ~ $ sudo pip install pynmea2
pi@raspberrypi ~ $ sudo pip install ISStreamer

 

Main Python Script

Here we will create the main script which will stream the GPS data to Initialstate.com.
The code below creates a separate thread which is used to monitor the serial port. This is needed because we have a pause in the main loop. The pause is there to limit how much data we upload over 3G.
If we did everything in the same thread during the pause, the serial buffer would fill up (it is FIFO) and when we get the next value from the buffer, it will be old by a few seconds. This happens every loop and eventually the data will be minutes or hours behind.

The access key below is not a valid key, it is just an example. You will need to replace it with your own key.

pi@raspberrypi ~ $ nano ~/GPStracker.py

#! /usr/bin/python

from gps import *
from time import *
import threading
import datetime
from ISStreamer.Streamer import Streamer

gpsd = None  #Setup global variable 

#Setup the Initialstate stream, give it a bucket name and the access key
streamer = Streamer(bucket_name="GPS_Tracker20190713", bucket_key="GPS_Tracker20190713", access_key="ist_W4aHj0eCkMjCD8JVpp3AMsKomys8NaD")


class GPSDcollector(threading.Thread):
   def __init__(self, threadID):
      threading.Thread.__init__(self)
      self.threadID = threadID
      global gpsd #bring it in scope
      gpsd = gps(mode=WATCH_ENABLE) #Start GPSD
      self.running = True #Start running this thread
   def run(self):
      global gpsd
      while gpsdThread.running:
        gpsd.next() 
        
if __name__ == '__main__':
  gpsdThread = GPSDcollector(1) # create a thread to collect data
  try:
    gpsdThread.start() # start it up
    while True:
        print 'GPS ' , gpsd.utc,'--> CPU time->',datetime.datetime.now().time() ,
        if (gpsd.fix.longitude<>0) and (gpsd.fix.longitude<>'nan'): #Only upload data if it is valid
          streamer.log("Location", "{lat},{lon}".format(lat=gpsd.fix.latitude,lon=gpsd.fix.longitude))
          streamer.log("speed",gpsd.fix.speed)
        print '  lat    ' , gpsd.fix.latitude,
        print '  lon   ' , gpsd.fix.longitude,
        print '  speed ', gpsd.fix.speed

        sleep(5)
  except (KeyboardInterrupt, SystemExit): #when you press ctrl+c
    print "\nKilling Thread..."
    gpsdThread.running = False
    gpsdThread.join() # wait for the thread to finish what it's doing
  print "Done.\nExiting."
  

 

Start the script automatically on boot

If you are doing remote monitoring, you would want the script to run on boot. To do this, we will create a small script which will start the main python program.

pi@raspberrypi ~ $ nano ~/GPStrackerStart.sh

copy in the below lines;

#!/bin/bash
sleep 15
python /home/pi/GPStracker.py &

The pause above is there to give the Pi time to boot and connect via PPP.

Make the script executable;

pi@raspberrypi ~ $ chmod +x ~/GPStrackerStart.sh

We will use cron to start the script every time the Pi boots;

pi@raspberrypi ~ $ crontab -e

Add the below line to the bottom

@reboot /home/pi/GPStrackerStart.sh &

Other Guides and Tutorials for BerryGPS-GSM

Get a GPS fix in seconds using assisted GPS on a Raspberry Pi with a BerryGPS-GSM

Typically, a GPS module can take a few minutes to get  Time To First Fix(TTFF), or even longer if you are in  built up areas(+20mins).  This is because the Almanac needs to be downloaded from  satellites before a GPS fix can be acquired and only a small portion of the Almanac is sent in each GPS update.

Assisted GPS speeds this up significantly by  downloading  ephemeris, almanac, accurate time and satellite status over the network, resulting in faster TTTF, in a few seconds. This is very similar how to GPS works on a smartphone.

The BerryGPS-GSM supports assisted GPS. The below video shows a comparison between assisted and normal GPS.

  • Assisted GPS takes 19secs to get a fix
  • Normal GPS takes 8min 22Sec to get a fix

 

How does the BerryGPS-GSM do this?

The two main components on the BerryGPS-GSM are;

The SARA-U201 can be configured to download GPS assist data and then pass this over the the GPS module. These two components speak to each other via i2c.

This assist data is downloaded by the SARA-U201 modem (not the Pi), therefore the modem needs to create an internal PDP (Packet Data Protocol) connection.

Once the PDP connection is made, the SARA-U201 will reach out to uBlox AssitNow servers and download the latest assist data. A valid token is needed to perform this, all BerryGPS-GSM have had this token pre-configured.

Continue reading Get a GPS fix in seconds using assisted GPS on a Raspberry Pi with a BerryGPS-GSM