Field Notes & Log

All Notes

Workbench writeups, protocol captures, hardware tests, and field experiments documenting radio frequency systems in the open.

All ESP32 LoRa Protocols Hardware Wi-Fi HaLow Wi-Fi Unlicensed / Part 15 MeshCore Guides

Nov 04, 2026

ProtocolsHardwareUnlicensedGuides

Technical vector illustration of Zigbee 3.0 coordinator, routers, end devices, and 2.4 GHz channel overlap map highlighting Channel 26 restricted band

Zigbee 3.0 & 802.15.4: 2.4 GHz Mesh Mechanics, Coexistence & Channel 26

A builder's guide to IEEE 802.15.4 and Zigbee 3.0: Coordinator/Router/End Device roles, 2.4 GHz Wi-Fi overlap maps, the Channel 26 FCC restricted band trap, and local ZHA control.

9 min read

Oct 28, 2026

ESP32WiFiProtocolsHardware

Technical vector illustration of ESP32 and ESP32-C3 microcontrollers with PCB trace antennas, sub-5ms action frame bursts, and AES-128 CCMP encryption

ESP-NOW Under the Hood: Action Frames, MAC Pairing & Sub-5ms Telemetry

A builder's guide to Espressif's connectionless protocol: 802.11 vendor-specific action frames, sub-5ms wake-to-transmit latency, AES-128 CCMP encryption, and channel coexistence.

8 min read

Oct 21, 2026

HaLowWiFiProtocolsUnlicensed

Technical vector illustration of Wi-Fi HaLow 802.11ah Sub-1GHz channels showing 1, 2, 4, and 8 MHz OFDM bandwidths in 902–928 MHz US ISM band

Wi-Fi HaLow (802.11ah): Sub-1GHz Megabit IP, 900 MHz Channels & Range

Everything builders need to know about IEEE 802.11ah Wi-Fi HaLow: 10x downclocked OFDM, 902–928 MHz US channels, WPA3 security, TWT sleep, and FCC Part 15 compliance.

9 min read

Oct 14, 2026

ProtocolsLoRaUnlicensedHardware

Technical vector illustration of Reticulum Network Stack cryptographic destination hashes, RNode transceivers, and multi-interface transport

Reticulum Network Stack: Cryptographic Addressing, Interfaces & Zero-Config

A deep dive into Reticulum Network Stack (RNS): self-sovereign cryptographic addressing, multi-interface transport, RNode LoRa links, LXMF, and Part 15 rules.

9 min read

Oct 07, 2026

MeshCoreLoRaProtocolsHardware

Technical vector illustration of MeshCore companion USB dongles, hilltop solar repeaters, room servers, and AES-128 packet framing

MeshCore Protocol: Structured Roles, Companion Topology & Repeaters

How MeshCore approaches sub-1GHz LoRa networking: distinct Companion, Repeater, and Room Server roles, deterministic routing paths, and AES-128 framing.

8 min read

Sep 30, 2026

LoRaProtocolsHardwareUnlicensed

Technical vector illustration of Meshtastic handheld nodes with OLED displays, 906.875 MHz spectrum waterfall, and multi-hop flood mesh routing

Meshtastic Off-Grid Messaging: Flood Routing, Airtime Budgets & FCC Limits

How Meshtastic builds peer-to-peer LoRa networks: managed flood routing, next-hop direct messaging, channel crypto, and why network hops are not FCC frequency hops.

8 min read

Sep 23, 2026

LoRaProtocolsUnlicensedGuides

Technical vector illustration of LoRaWAN US915 gateway, outdoor collinear antenna, and Class A/B/C end devices with uplink frequency spectrum

LoRaWAN in the US: Architecture, US915 Channels, and Part 15 Reality

A builder's guide to LoRaWAN network architecture, US915 uplink/downlink channels, Class A/B/C receive windows, OTAA nonce traps, and FCC Part 15 limits.

9 min read

Sep 16, 2026

LoRaUnlicensedGuidesHardware

Technical illustration of LoRa chirp spread spectrum waveforms, SX1262 transceiver module, and FCC Part 15 regulatory framework

What LoRa Actually Is: Physical Layer Mechanics, FCC Part 15, and the 1-Watt Trap

A builder's guide to Chirp Spread Spectrum physics, symbol time math, why 125 kHz LoRa cannot use the §15.247 1-Watt digital modulation shortcut, and how Part 15 differs from Part 97.

8 min read

Sep 09, 2026

GuidesUnlicensedProtocolsMeshCore

Technical illustration showing spectrum analyzer displays and signal sweeps across LoRa, Wi-Fi HaLow, Sub-1GHz, and 2.4 GHz bands

Welcome to OpenRF Note: An Unlicensed RF & Wireless Notebook

Why OpenRF Note exists: documenting FCC Part 15 unlicensed spectrum, exhaustive channel rosters, protocol packet framing, coexistence maps, and diagnostic RF engineering in the open.

5 min read