3  Deployment

This chapter covers testing and deploying the WiFi sensing service. You will first test in a controlled environment, then enable the service to run at boot, and finally test in the field without Ethernet.

3.1 Test in Controlled Environment

Run the Script

Power off the Pi, insert the external WiFi adapter, and power it back on.

Connect via SSH and verify the network interfaces:

ifconfig

The internal WiFi should be wlan0 with a MAC address starting with b8:27:eb. External adapters appear as wlan1, wlan2, etc.

Enter superuser mode and run the sensing script:

sudo su
python3 capture-scripts/code/start.py

Let it run for about 2 minutes, then stop with Ctrl+C.

  • -i: Retain raw WiFi packets
  • -b: Enable Bluetooth sensing

See the capture-script repository for all options (link anonymized for review).

Verify the Results

Access the Pi’s shared folder by typing \\raspberrypi\share in File Explorer.

In the stats folder, verify that file names reflect the execution time. Then check that the same files have been uploaded to Dropbox.

In the data folder, check for the WiFi packet file. If you used -b, a Bluetooth file should also appear. Use DB Browser for SQLite to inspect the data.

3.2 Enable the Service

Once testing is complete, configure the Pi to start sensing automatically at boot:

bash capture-scripts/service.sh

Follow the prompts and verify the service is running. Press Ctrl+C to exit the status display.

Note

The script has a 30-second delay at startup. To pause sensing for file transfers or maintenance, stop the service within this window:

sudo systemctl stop sensing.service

3.3 Test in the Field

This section tests the service without Ethernet, simulating real-world deployment. The two adapters divide the work: the internal adapter (wlan0) briefly connects to your hotspot in station mode to upload status files, while the external adapter switches to monitor mode for packet capture.

Prepare the Hardware

Turn on your mobile hotspot and connect an external battery to power the Pi.

Connect the battery

Enable your hotspot

Station Mode

When the Pi boots, the internal adapter (wlan0) first connects to your hotspot in station mode. In this phase:

  • The external adapter’s indicator light turns on
  • The Pi appears on your hotspot’s connected devices list
  • Status files begin uploading to Dropbox

Once connected, verify that status files appear in your Dropbox.

Note

The raspberrypi device may remain visible on your hotspot’s list briefly. The script disconnects the internal adapter (wlan0) shortly after startup, once the initial status upload completes.

Monitor Mode

After the initial connection, the external adapter switches to monitor mode for passive packet capture. In this mode:

  • The external adapter’s indicator light turns off
  • The Pi disappears from your hotspot’s connected devices list
  • Packet capture begins

To end sensing, unplug the battery. Review the results using Ethernet or your mobile hotspot, as in the controlled environment test.