Dude, where is my car? (Raspberry Pi Edition) - Part 1

A year ago I started a project to be able to track my car in real time. Additionally, my idea was to use it as a car alarm system. I went through different iterations until I had a working system with which I was satisfied. This is the first part of a blog post series that describes how to track your car in real time and how to use it as a car alarm system.

• Part 1: Choosing the GPS tracking system and tracking my car with a Raspberry Pi (this article)


• Part 2: Using an old Android mobile phone to track my car

The Beginning: GPS Tracking System

The first idea I had was to put a Raspberry Pi into my car that gathers the GPS data and submits it to a server. So I started to look into GPS tracking systems usable with Linux. Unfortunately, all GPS tracking systems I found where either in a way that I had to host them myself by using MQTT or they were only available as a service. The self-hosting suited me fine, but the MQTT part not. Why not? Because I have to open a port to the Internet for a MQTT server which I do not know the code quality of. Being a security enthusiast, I would rather have the GPS tracking system using HTTPS via a standard web server which I know is tested a millionfold. The GPS tracking as a service would also be fine for me as long as it gives me access to the data via an API. Unfortunately, the data is stored unencrypted (no end-to-end encryption) by the services and therefore do not protect my privacy (I do not want some provider to know where my car is all the time). Also, some other GPS tracking services did not have an API to fetch the stored data.

So, I started to develop an end-to-end encrypted GPS tracking system myself, called ChasR. The complete source code is available on Github if you want to host it yourself or you can just use it as a service (since the data is stored encrypted, your privacy is protected).


The Raspberry Pi

In order to install the GPS tracking into my car, I bought a Raspberry Pi (version 1), a USB GPS receiver and an UMTS modem. Obviously, the GPS receiver is used to gather the current location. The UMTS modem is necessary so the Raspberry Pi can transfer the GPS location data to the server. With the help of the Linux client for ChasR, the Raspberry Pi is able to do that. An early test setup looked like this:



To not drain the battery of my car, I connected the Raspberry Pi to the ignition of my car. Meaning, every time I started the engine of my car, the Raspberry Pi got powered up. However, I had a problem. Every time I turned off the engine of my car, the Raspberry Pi lost also power. First I thought I do not care. However, the temporary files stored locally by the ChasR logger were corrupted by this. Therefore, I added code to the client that syncs the filesystem each time a file is touched by the logger. As a result, the loss of power did not corrupt the temporary files anymore.

Finally, I was able to track my car in real time either on my browser at home or via an Android App on my mobile phone: