OffGridPete writes that Fieldwatch is a passive, receive-only Android app that listens for nearby Wi-Fi access points and Bluetooth LE advertisements to help users identify radio sources around them. Built as a personal hobby tool, it runs entirely offline with no account, no backend server, and no dongle. The app was originally named Spectre but was renamed to avoid confusion with another existing app, and it is distributed as a sideload APK under the MIT License.
- Includes an extensible signature library for identifying radio sources
- Features GPS co-travel detection ("possible tail") and a Debrief report
- Privacy mode can mask Remote IDs on-screen while full coordinates are retained in logs
- Not capable of capturing Wi-Fi probe frames, Bluetooth Classic, cellular, or direction-finding data
- Includes an extensible signature library for identifying radio sources
- Features GPS co-travel detection ("possible tail") and a Debrief report
- Privacy mode can mask Remote IDs on-screen while full coordinates are retained in logs
- Not capable of capturing Wi-Fi probe frames, Bluetooth Classic, cellular, or direction-finding data
Jenny List writes about how an undocumented feature in certain ESP32 chips allows the raw I/Q stream to be tapped before the WiFi modem, effectively turning them into software-defined radio receivers. Discovered independently by Espargos and a Reddit user, the mode supports both 2.4 and 5 GHz bands but is limited to receive-only operation.
- Only works on ESP32 variants with earlier Tensilica hardware; Bluetooth-only and non-radio P4 chips won't work
- Transmit capability appears possible but remains undocumented, with the discoverer refusing to share due to "rule 3"
- The 80 Msps 32-bit/sample data rate creates bandwidth challenges for external transfer via SDIO or UART interfaces
- Only works on ESP32 variants with earlier Tensilica hardware; Bluetooth-only and non-radio P4 chips won't work
- Transmit capability appears possible but remains undocumented, with the discoverer refusing to share due to "rule 3"
- The 80 Msps 32-bit/sample data rate creates bandwidth challenges for external transfer via SDIO or UART interfaces
The SuperBase is a $75 standalone Meshtastic device from muzi works, combining a Base Uno and Super IO board inside a 3D-printed translucent PETG case. It offers built-in GPS (dual GPS/BDS), a digital compass, a large square OLED screen, and a 1500mAh battery that lasts up to 2 days with GPS enabled. Available pre-assembled or as a DIY kit requiring soldering.
- Powered by the nRF52840 SoC and SX1262 radio, supporting both 868MHz and 915MHz via a universal stubby antenna
- Weighs 80.3g (2.8oz) with antenna; dimensions roughly 48 x 80 x 19mm
- Features a 2-mode power switch, tone buzzer for notifications, fast USB-C charging up to 1A, and onboard RTC
- Customer reviews (4.55/5 from 11 reviews) praise portability and ease of use but note the translucent case chips easily and the display shows horizontal line shadowing at max brightness
- Powered by the nRF52840 SoC and SX1262 radio, supporting both 868MHz and 915MHz via a universal stubby antenna
- Weighs 80.3g (2.8oz) with antenna; dimensions roughly 48 x 80 x 19mm
- Features a 2-mode power switch, tone buzzer for notifications, fast USB-C charging up to 1A, and onboard RTC
- Customer reviews (4.55/5 from 11 reviews) praise portability and ease of use but note the translucent case chips easily and the display shows horizontal line shadowing at max brightness
A technical overview of intercepting and decoding satellite communications, detailing hardware, software, and techniques used for signal acquisition and decryption.
The ITU‑R Recommendation P.833‑2 provides guidance on estimating radio‑wave attenuation caused by vegetation for frequencies between 30 MHz and 60 GHz. Because foliage conditions vary widely and experimental data are limited, the recommendation offers separate models for different frequency bands and path geometries. For a terrestrial link with one end inside a woodland, the extra loss is expressed using two parameters: the specific attenuation rate γ (dB / m) that describes short‑range scattering loss, and a maximum attenuation Am that caps the total excess loss due to additional mechanisms such as surface‑wave propagation and forward scattering. The excess attenuation for a path length d inside the vegetation is given by Aev = Am 1 – exp(–d γ / Am) » . This formulation allows engineers to calculate the additional loss when a transmitter or receiver is located within dense vegetation.
Information about Meshtastic, an open-source, decentralized, off-grid mesh network, and the MDARC's involvement with it, including node locations and configurations.
Meshnology offers a range of IoT and Meshtastic related products including ESP32 LoRa modules, batteries, antennas, development boards, sensors, and cases.
This project details building a system to send images in real-time from high altitude using SSTV (Slow-Scan Television) and PMR walkie-talkies. It covers hardware setup, code configuration, and launch results. Note: PMR is under ham radio license in US.
Meshtastic offers a text messaging service that operates without internet, satellite, or cellular connections, using radios to send and receive messages and GPS coordinates. It's designed for ease of use, allowing anyone to communicate in areas without cellular coverage or as a backup communication method.
Utilizing LoRa (Long Range) technology, Meshtastic connects nodes (small, battery-powered radios) within signal range, forming a mesh network. Messages hop from node to node, reaching recipients even without direct line-of-sight, thanks to the mesh's retransmission capability. Security is maintained through encryption, ensuring that only intended recipients can read messages.
**Getting Started:**
1. **Choose a Node:** Select a LoRa node compatible with your region (915MHz for North America, 868/433MHz for Europe). Popular choices include the HelTec ESP32 LoRa V3 and the Seed Studios SenseCAP T1000-E.
2. **Install Meshtastic:** Flash your node with Meshtastic software using instructions from flasher.meshtastic.org.
3. **Download the App:** Install the Meshtastic app on your device to pair with the node and join the mesh.
4. **Join a Mesh:** Connect with existing nodes in your area or start your own mesh network. Engage with local mesh groups via channels like LongFast for community interaction.
Utilizing LoRa (Long Range) technology, Meshtastic connects nodes (small, battery-powered radios) within signal range, forming a mesh network. Messages hop from node to node, reaching recipients even without direct line-of-sight, thanks to the mesh's retransmission capability. Security is maintained through encryption, ensuring that only intended recipients can read messages.
**Getting Started:**
1. **Choose a Node:** Select a LoRa node compatible with your region (915MHz for North America, 868/433MHz for Europe). Popular choices include the HelTec ESP32 LoRa V3 and the Seed Studios SenseCAP T1000-E.
2. **Install Meshtastic:** Flash your node with Meshtastic software using instructions from flasher.meshtastic.org.
3. **Download the App:** Install the Meshtastic app on your device to pair with the node and join the mesh.
4. **Join a Mesh:** Connect with existing nodes in your area or start your own mesh network. Engage with local mesh groups via channels like LongFast for community interaction.
The T-Deck is a compact device with a 2.8-inch IPS LCD touch screen, integrated keyboard, trackball, microphone, and speaker, running on an ESP32-S3 dual-core processor. It supports various frequencies and includes a GPS module and battery in its Plus variant. It features a U.FL/IPEX antenna connector for LoRa and can be flashed using Espressif's firmware download mode.
