A következő címkéjű bejegyzések mutatása: GPS tracking. Összes bejegyzés megjelenítése
A következő címkéjű bejegyzések mutatása: GPS tracking. Összes bejegyzés megjelenítése

2013. augusztus 26., hétfő

Cheap car GPS tracking with OpenWRT I. The basics


My goal to assembly a reliable GPS tracking system by cheap components with OpenWRT.
I would like to install it into my car. It would record the GPS data (latitude, longitude, speed) in 10 seconds and uploads to a server when it hase WIFI connection.
In my firs run it would scan the available wifi connections frequently and try to connect and upload the recorded data trough non-secure access points.
I would like to make a simple web page where I can follow the car's movement on the google map.


I'm good with it. It is running in pilot mode.

The parts of the project:
  • TP-LINK  TL-MR3020 router running OpenWRT
  • USB Hub to share to multiple the USB connectors
  • Flash drive to store recorded data
  • GPS receiver  to collect data
  • Power bank to work in case the car's battery disconnected
  • PCA with power connectors, fuse, DC-DC converter, etc
  • Webserver listening on the Internet

Here you can see a picture from the current status:

GPS tracking system

First I present the components then I write the "why" in the following posts.


TP-LINK  TL-MR3020 
This is a cheap, portable router which can share your 3G mobile connection as a wifi access point. It has one piece of USB connector, one peace 10/100Mb/s LAN connector and built-in 5DBm WIFI antenna.
An advantage of this device is it can run by USB power (5V, max 500mA).
I've replaced the original firware to OpenWRT by this tutorial.
It was very simply, works out of the box.

USB Hub
It is a cheap one, but can work with external power. The external power is important because the GPS receiver use approx 300mA. Without the extra power the Linux wrote I/O error into the log...
In the first step I use one connector for the USBdrive and another for the GPS receiver. (I plan to complete the system with a 3G stick to send the recorded data to the server immediately)

Flash drive
The router have only 4MB Flash storage, therefore it needs more space to store the recorded data. I've used a flashdrive 2GB space.

GPS receiver
During the period I've collected data to my project I found this and this article. They used the Globalsat BU-353 GPS Reciever. It is the most expensive part of the project, but it works pretty good.

Power bank
I've chosen a 5V and 2600mAh  power bank which can charge from USB connector. Optimally it will not works because I will connect the stuff onto constant current source in the car. One of my expectation is it have to works for a while when  external power is not available. It has a normal USB connector for power input and a micro USB for power output. Both connectors are connected constantly.

PCA
As you can see in the picture I soldered some components onto a project board. The most important component is the DC-DC converter which makes stable 5V  from the car's 12-14V.

Webserver
Basically the system store the collected data on the flash drive but in case it has connection to the internet it synchronize the local data with the remote database.
I would like to make a simple web page where i can follow the car's movement on the google map.
It would inform the visitor about the car's current position, the last "hearthbeat" when the car logged in the page, etc


I will coming soon with the presentation of the components