Published July 28, 2017 © GPL3+

Onion Omega2 GPS Info to OLED + Losant map

Display GPS info on the OLED and put it on a map dashboard at Losant. The map is much more detailed than what's shown here (privacy).

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Onion Omega2 GPS Info to OLED + Losant map

Things used in this project

Hardware components

Onion Corporation Omega2 Plus

Onion Corporation OLED Expansion

Optional

Onion Corporation Expansion Dock

GPS receiver (generic)

Software apps and online services

Losant Platform

Story

Ideation

I had just started really playing around with the Onion Omega2+ and ran into Brad Buskey's GPS Info to Oled article around the same time I got the "Two Bullet Tuesday" email from Onion with instructions on setting up the Omega with Losant. Well, I can't resist a mashup when I see one, so I had to put the two together.

This is just a quick and dirty example to show that the GPS info can be sent up to Losant to display on a map dashboard. I'm sure there are better ways to do a lot of it (in particular, the "awk and kill" seems like an awful way to get things done).

Step 1

It would be easier to just implement Brad's "GPS Info to OLED" first, then get the Losant setup going. Grab the "getgps.sh" and "showgps.py" files. Edit the "getgps.sh" file and put your device ID in the placeholder. Once you're connected to Losant, you can create (on your Losant "Device") a "gps" attribute to send data to (Data Type: GPS String, Name: gps).

Step 2

Then in the upper left go to the "Dashboards" menu and choose "+ Create Dashboard" and give it a name (I just called mine "map") and click the green "Create" button at the bottom. Now you can choose a "block" to add (I chose the "GPS History" block (the heatmap looks interesting as well):

The block should configure itself for the most part but you may want to look at the "Duration" (do you only want to see the last known location or see a whole "trip" on the map?) or tweak other settings. There is a live preview in the upper right so you can get an idea what your map will look like.

Troubleshooting

If you aren't getting any data in your map, the best place to start is the "Communication Log".

If the data is getting to Losant, but it isn't valid JSON or from there it isn't valid NMEA data then it won't work. The log should shed some light on the problem. Most of the time the first MQTT message at boot is missing the NMEA info and will be marked bad. The messages following afterward should be ok.

A valid JSON string for this setup would look like this:

{"data":{"gps":"$GPGLL,3906.71226,N,8430.74572,W,000653,A,*24"}}

To display the data sent to the OLED:

cat /root/gpsinfo.txt

To display the most recent GPS output from the "awk" line:

cat /root/gpsnema.txt

To display the JSON data generated by the script:

cat /root/gpsmqtt.txt

Losant's definition of the GPS data it expects to receive in this case is this one:

NMEA GLL Example:

$GPGLL,3906.71226,N,8430.74572,W,000653,A,*24

#!/bin/ash

# Run the loop to send it
while true; do

# Get updated gps info and write it to the nema file.
awk '/GPGLL/ {print}' /dev/ttyACM0 > gpsnema.txt &
sleep 1
killall awk
sleep 1

# Build the json string.
output="$(tail -1 gpsnema.txt)"
output="{\"data\":{\"gps\":\"${output}\"}}"

# write the json string to a file.
echo $output > /root/gpsmqtt.txt

# Write file for output to oled
ubus -S call gps info > /root/gpsinfo.txt


# Send the json data to losant.  You'll need to put your Losant device ID here.
mosquitto_pub -f /root/gpsmqtt.txt -t 'losant/xxxxxxxxxxxxxxxxxxxxxxxxx/state'

# call python script to write the data to the oled
python /root/showgps.py

# Exit the script
sleep 60
done
exit 0

#!/usr/bin/env python

#======================================================
# Show GPS Location on the OLED Screen on the Omega 2+
# Written By: Brad Buskey
# Contact Me: deckyon@gmail.com
#======================================================

#Initialize the script and pull in the required libraries.
from OmegaExpansion import oledExp
import time
import json
import os

# Initialize and clear the OLED screen
oledExp.setVerbosity(0)
oledExp.setTextColumns()
oledExp.driverInit()

# Draw the header for the display
oledExp.setCursor(0, 0)
oledExp.write("__Current GPS Info__")
oledExp.setCursor(1, 0)
oledExp.write("====================")

# Check fo the file size of gpsinfo.txt and exit if < 1
if os.path.getsize('/root/gpsinfo.txt') == 0:
	# File is empty or doesnt exist
	oledExp.setCursor(3, 0)
	oledExp.write("GPS Info doesnt seem")
	oledExp.setCursor(4, 0)
	oledExp.write("to exist.")
	oledExp.setCursor(6, 0)
	oledExp.write("Check GPSInfo file.")
	exit()

# Get the data fro mthe file written to in the shell script.
with file('/root/gpsinfo.txt', 'r') as gpsfile:
	gpsinfo = json.load(gpsfile)
	
# Pause the script and pretend to look stuff up.
time.sleep(2)

# Test for the existence of a GPS signal
if gpsinfo.has_key('signal'):
	# No GPS Signal, let the OLED reflect that
	oledExp.setCursor(3, 0)
	oledExp.write("No GPS signal found")
	oledExp.setCursor(4, 0)
	oledExp.write("Please try later!")
elif gpsinfo.has_key('latitude'):
	# Pull out the data from the desired fields in the dictionary 'gpsinfo'
	lat=gpsinfo['latitude']
	lon=gpsinfo['longitude']
	elv=gpsinfo['elevation']
	cou=gpsinfo['course']
	spd=gpsinfo['speed']
	# Build the data strings to be written to the OLED
	lat="Latitude : "+lat
	lon="Longitude: "+lon
	elv="Elevation: "+elv
	cou="Course   : "+cou
	spd="Speed    : "+spd
	# Draw out the rest of the information gathered from 'gpsinfo'
	oledExp.setCursor(2, 0)
	oledExp.write(lat)
	oledExp.setCursor(3, 0)
	oledExp.write(lon)
	oledExp.setCursor(4, 0)
	oledExp.write(elv)
	oledExp.setCursor(5, 0)
	oledExp.write(cou)
	oledExp.setCursor(6, 0)
	oledExp.write(spd)
	
# Exit the script cleanly
exit()

Credits

Matt Nelson

0 projects • 2 followers

Thanks to Brad Buskey and Lazar Demin (greenbreakfast).

Onion Omega2 GPS Info to OLED + Losant map

Things used in this project

Hardware components

Software apps and online services

Story

Ideation

Step 1

Step 2

Troubleshooting

Code

getgps.sh

showgps.py

Onion to Losant Setup Script

Credits

Matt Nelson

Comments

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Onion Omega2 GPS Info to OLED + Losant map

Onion Omega2 GPS Info to OLED + Losant map

Things used in this project

Hardware components

Software apps and online services

Story

Ideation

Step 1

Step 2

Troubleshooting

Code

getgps.sh

showgps.py

Onion to Losant Setup Script

Credits

Matt Nelson

Comments

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