📡 WiFi Heatmap Generator

A cross-platform desktop application for collecting and visualizing WiFi signal strength across a physical space — with or without a floorplan.

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Requirements

• Python 3.10+
• tkinter (usually bundled with Python; on Linux: sudo apt install python3-tk)

Installation

pip install -r requirements.txt

Usage

# Launch the GUI
python main.py

# Load an existing session on startup
python main.py --session my_office.json

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Workflow

1. Launch the app. The canvas starts in grid mode (no floorplan).
2. (Optional but recommended) Click 🖼 Load Floorplan in the sidebar to load a PNG/JPEG image of your floor layout. This significantly increases the accuracy and usefulness of the heatmap.
3. Click 🔄 Refresh Scan (right panel) to detect nearby access points.
4. Select an AP from the list.
5. Walk to a location in your space and click ▶ Scan & Place. The app scans WiFi (averaged over 5 readings) and waits for you to click your current position on the canvas.
6. Repeat step 5 from at least 6–10 different locations for a good heatmap. Cover corners and edges — they matter most for interpolation quality.
7. Once you have enough points, the heatmap auto-updates after each scan.
8. Switch between APs to compare coverage.
9. Export PNG for sharing, or Save Session to continue later.

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Platform Notes

OS	Scan Method	Notes
Windows	netsh wlan show networks	No admin required
Linux	nmcli → fallback iwlist	May need sudo for iwlist
macOS	airport CLI tool	No admin required

Linux Permissions

If scanning fails on Linux, try:

# Grant your user permission to scan (preferred)
sudo setcap cap_net_raw+eip $(which python3)

# Or run the app with sudo (not recommended long-term)
sudo python main.py

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Floorplan Tips

• Use a simple overhead floor plan at any scale — even a hand-drawn photo works.
• PNG with transparency supported.
• The image is scaled to fit the canvas automatically.
• Providing a floorplan increases accuracy because measurement points map to real room features, giving better spatial context for interpolation.

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Signal Quality Reference

dBm range	Quality
-30 to -50	Excellent
-50 to -65	Good
-65 to -75	Fair
-75 to -90	Poor

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Files

File	Purpose
main.py	GUI application entry point
scanner.py	Cross-platform WiFi scanning
interpolator.py	Spatial interpolation (RBF / cubic / linear)
renderer.py	Matplotlib heatmap rendering
data.py	Session data model and JSON persistence
requirements.txt	Python dependencies