WiFi-Scanner

Introduction

While studying Electrical Engineering at HAW Hamburg there is a mandatory project to undertake with co-students to train team play and practice technical expertise. The project can be chosen by the students themselves as long as it has a relation to Electrical or Information Engineering.

Our projects aim was to build an WiFi-Scanner - a device which can rotate around it's yaw- and pitch-axis and scan the wireless network access points via directional antenna. Thus it can determine the signal strength of an WiFi-Network in respect to a vantage point and display it as a heatmap.

In the following there are some impressions of the making-of and the usage of the device.

The team members were

Jonas Buuck

Tobias Claus

Stefan Ralfs

Timo Vandrey

Impressions

The mechanical base and housing is completed. We used a ball bearing to support the aluminum pipe.

A little glance into the (admittedly a bit untidy) cable management and required modules. The red modules are the stepper motor driver modules. In the back, behind the battery, you can see the voltage supply units.

The whole apparatus opened. The directional antenna can be seen hanging from the head. Also, the yaw and pitch motors are now installed.

A look into the head. The ESP32 captures the network data and sends it via serial comm to the RasbPi.

A first test. Here a created heatmap and the GUI can be seen.

Last test run

A panorama view of the vantage point from which the apparatus scanned the surroundings. We also indicated the network access point positions via red circles.

This is the resulting heatmap. Unfortunately the apparatus had a little problem in the yaw range from 45°-90°. In that range the stepper motor step made barely any progress. The result is a squashed heatmap. Also, the degrees ticks aren't right. Unfortunately, due to time constraints, we weren't able to fix these issues.

Here, both the heatmap and the vantage point panorama are overlapped. The heatmap was (rather haphazardly) stretched so it would fit a little bit better. We scanned for the network access point "m3", and as you can see, the signal strength is higher in the direction of "m3".

Conclusion

Due to time constraints, we weren't able to fix the issues we discovered. There were a few unfortunate things going on, for example the 45°-90° range problem, the signal strengths contrast and quality, heatmap display issues, etc.

We would be able to fix all of them and now have a better understanding of what to do better the next time. It was a very fun project and we got an A+-rating from our professor.

Download

Here you can download the report on the whole project.

Unfortunately it is only available in German.

If you want any source code or have other questions to the project, just contact me.