lora-params-matrix

Generates a comprehensive heatmap visualization of LoRa radio parameters across all bandwidth / spreading factor combinations, with annotations for common protocol presets.

Output

A 2×3 grid of annotated heatmaps covering:

• Link Budget — range potential in dB
• Bit Rate — CR4/5 and CR4/8
• Figure of Merit — Link Budget × Bit Rate
• Throughput Efficiency — bps per dB of link budget
• Time on Air — 1-byte payload
• Time on Air — 250-byte payload

Preset annotations

Label	Protocol	BW / SF / CR
[L]	LoRaWAN EU868	125kHz, any SF, CR4/5
[C]	MeshCore EU	125kHz, SF9, CR4/8
LF	Meshtastic Long Fast	250kHz, SF11, CR4/5
LS	Meshtastic Long Slow	125kHz, SF12, CR4/8
LMo	Meshtastic Long Moderate	125kHz, SF11, CR4/8
MF	Meshtastic Medium Fast	250kHz, SF9, CR4/5
MS	Meshtastic Medium Slow	250kHz, SF10, CR4/5
ShF	Meshtastic Short Fast	250kHz, SF7, CR4/5
ShS	Meshtastic Short Slow	250kHz, SF8, CR4/5
ST	Meshtastic Short Turbo	500kHz, SF7, CR4/5

Chart

Usage

python lora-params-matrix.py

Displays the chart and saves it as lora_charts.png.

Dependencies

numpy
matplotlib

Radio parameters

Based on the Semtech SX1261/2 datasheet (Rev 2.2, Dec 2024):

• TX power: +22 dBm (SX1262 max)
• Noise figure: 6 dB
• SNR thresholds: SF7 = −7.5 dB … SF12 = −20 dB (Table 6-1)
• LDRO enabled when symbol time ≥ 16.38 ms