Category: Other

October 8, 2026

FliteGrid: A Crowdsourced Drone Detection Network That Pays Feeders US$50 A Month

Thank you, Chris, for writing in and sharing news about the recent launch of FliteGrid's hex claiming scheme. FlightGrid is a crowdsourced drone-tracking network that will pay feeders in an eligible hex grid $50 a month to run a drone-detection sensor. Chris explains:

The US government is building out Unmanned Traffic Management (UTM), which will be the equivalent of air traffic control for drones. This will make it possible to automate things like shipping, emergency response, infrastructure inspections, and more all over the country. To do that, they'll need awareness of every drone in the sky just like they have for every plane today, and FliteGrid is our solution to providing it.

The devices themselves are custom sensors that receive Remote ID transmissions. That's the standard the FAA created for drones to transmit identifying information, which it now requires all drones in America to broadcast. Serial number, location, altitude, operator location, etc. Remote ID can be broadcast on four different protocols, so we've got four receivers in each piece of hardware; two WiFi and two Bluetooth. That data is then uploaded onto the SkySafe platform, which provides a realtime map of every drone in the sky.

The catch to getting paid is that you need to 1) pay a $100 refundable deposit to receive their hardware, and 2) place and run it in a hex grid that offers to pay. The paying hex grids are mostly around US airports and critical infrastructure right now, so you'd need to live in, or have access to a roof in those areas to host the device. Payment is given in USDC, a stablecoin cryptocurrency pegged to the US dollar.

FliteGrid Hexes: Red - Claimed, Green - Available to claim with $50 p/m payout, Purple - Requested by community, Black - Requestable.

FliteGrid/SkySafe is able to pay users because operators of critical infrastructure and large facilities such as airports, universities, energy infrastructure, the US military, DHS, and the DOD will pay for real-time awareness of the airspace above them. SkySafe has been around since 2015, has raised around $50M in funding, and has contracts with many of the previously listed organizations. Chris notes that the service has already been used successfully in operations like busting gangs smuggling drugs into prisons via drones.

The FliteGrid sensor appears to be a computing device with WiFi and Bluetooth radios repurposed to detect Remote ID, with each radio connected to a higher-gain external antenna. Recently, on the blog, we have seen DIY Remote ID detectors made from ESP32s and other commodity Bluetooth hardware.

Since a 2024 mandate, drones over 249 g in the USA must transmit Remote ID signals for tracking and identification purposes, similar to how ADS-B is used for larger aircraft. For ADS-B, flight aggregation services such as FlightAware/FlightRadar24/ADS-B Exchange etc. already exist, with volunteer feeders setting up stations that can cover up to 400km. However, unlike ADS-B, Remote ID is transmitted with single-digit milliwatts of power, compared to a minimum of 70W for ADS-B, so its reception range is limited, making a dense distributed reception network like SkySafe for Remote ID very important. Individual SkySafe hex grids cover just under 1km of area.

FliteGrid cannot detect drones that are not transmitting Remote ID, though Chris mentions that government infrastructure and facilities may use normal radar to detect these. A radar detection that does not correlate with a SkySafe detection would confirm that a drone is a potential threat.

October 1, 2026

Various Projects Independently Find Hidden SDR Capabilities in ESP32 Microcontrollers

Back in 2025, we posted about ESPARGOS, a phased array of many patch antennas, each connected to an ESP32 WiFi microcontroller. ESPARGOS could be used to determine the direction of arrival for WiFi signals and create a live augmented reality heatmap.

Recently, the ESPARGOS team has made an exciting discovery. They found that several ESP32 chips have an undocumented feature that lets the firmware bypass the fixed WiFi and Bluetooth functionality and instead capture raw IQ baseband samples. As a result, several ESP32 models can now be used as an internal SDR covering 2.2–2.7 GHz, plus 4.8–6.0 GHz on the ESP32-C5, with up to 80 MS/s sample rate and roughly 13–54 MHz of analog bandwidth, depending on the chip.

However, for use as a general-purpose PC-connected SDR, the output bandwidth is insufficient, so only snapshots of data can be exported to a PC. This means that the SDR will only work as a spectrum analyzer, and demodulating or decoding continuous radio data is not possible with just an ESP32. The exception is the new ESP32-S31, which can stream continuously at up to 16 MS/s over its Gigabit Ethernet interface, with a SoapySDR driver for GNU Radio and gqrx coming soon. If you want to try it yourself, the ESP-WebSDR page lets you flash the firmware to most ESP32 dev boards directly from your browser and view a live spectrum and waterfall.

Furthermore, ESPARGOS notes that phase-coherent IQ sample capture is now possible with their hardware. This means ESPARGOS is no longer limited to WiFi and Bluetooth signals; it can now perform direction finding on any arbitrary signal in the 2.4 GHz band. The team also says phase-coherent transmissions would be possible, but they aren't implementing them right now because they could be misused.

It also seems that, independently, at least two other projects discovered the same or similar features around the same time, but to solve different problems.

Over on Reddit, user /u/h0m3us3r discovered the same feature and uploaded it to GitHub on Sept 26, and recorded a video showing an ESP32-S3 working as an SDR with an FPGA used as a USB3 front end. Unlike ESPARGOS, h0m3us3r's project streams the raw IQ data to a PC continuously via the FPGA rather than in snapshots, so full demodulation/decoding on PC should be possible. However, the current prototype uses the FPGA to clock the ESP32, which results in poor phase noise. So if the clocking issues can be resolved, an ESP32 combined with an FPGA could make a standard general-purpose SDR, like the RTL-SDR, but with a 2.2–2.8 GHz frequency range and up to 80 MHz of bandwidth.

Another project that seems to be using a somewhat similar finding is C5VRX, which was first uploaded to GitHub on August 13. C5VRX uses an ESP32-C5 as a 5.8 GHz real-time FPV video receiver. Although this project appears to use a different mechanism, the result is similar: it uses an undocumented IQ data stream on the ESP32 to sample FPV signals and demodulate them onboard, outputting analog composite video through a simple resistor DAC. The project is still a work in progress and doesn't yet work reliably at range.

October 1, 2026

Using an Affordable Optical Encoder as an SDR Tuning Wheel

Thank you to Gerrit (PA3BYA) for writing in and sharing a hardware project he completed that combines an affordable optical encoder and a microcontroller with custom firmware to create a high-resolution USB mouse wheel for SDR tuning. Many people prefer using a knob to tune through the bands rather than a keyboard and mouse. Gerrit writes:

Although I initially developed it for use with the RTL-SDR, it is actually a general-purpose tuning solution that can be used with virtually any SDR software. Many SDR projects use a cheap mechanical rotary encoder with, for example, 24 pulses per revolution.

But why settle for a 24-pulse mechanical encoder when an affordable optical encoder can provide 600 pulses per revolution? For this quick SDR experiment, I combined a high-resolution optical encoder with a tiny Digispark ATtiny85 and turned it into a standard USB mouse wheel for tuning.

The result is a surprisingly simple and platform-independent tuning control that works with SDR software on macOS, Windows, Linux, and even a Raspberry Pi.

The encoder he used is a cheap Chinese part, costing around 17 Euros. However, one interesting issue that Gerrit encountered was that the cheap encoder would not reliably operate when powered from 5V, even though the operating voltage was specified as 5V to 24V. To fix this, he suspected that the input LDO was dropping too much voltage at the low 5V end, so he modified the encoder by shorting the input and output of the 78M05 regulator, to allow direct 5V power without any dropout.

His firmware for the ATtiny85 is open source and can be found on GitHub.

The Optical Encoder and ATTiny85 Microcontroller

October 1, 2026

NNJ-SDR++: Improved Firmware and Software for Kintex-7 AD9361 B210 Clones

USRP B210 Chinese clones can now be commonly found on marketplace sites for less than USD$300. This is a bargain, considering that an original USRP B210 (board only) costs US$2,387. The disadvantage is, of course, janky ported firmware that doesn't support all the available features and doesn't maximize the available performance.

Recently, Fabrizio Francione wrote in and wanted to share his new firmware and software project, called "NNJ-SDR++ UHD Edition V1.0". This project consists of improved firmware that unlocks the full sample rate, fixes various problems, and enables the onboard GNSS receiver. It also includes a modified SDR++ frontend that exposes more controls. Fabrizio writes:

The work involved substantial FPGA and software development rather than simply customizing the SDR++ interface. Starting from the original B210-compatible architecture, I progressively redesigned and extended several areas of the firmware, including improved CIC numerical handling, RX/TX fixed-point processing, BRAM-based asynchronous transport FIFOs, CIC passband compensation, a wideband FIR receive path, ADC clipping/overload telemetry, runtime FPGA control and diagnostics, and a dedicated wideband profile for operation at up to 56 MS/s.

I also finally integrated the board's onboard u-blox MAX-M10S GNSS receiver directly with the FPGA, including GPS UART data, internal PPS capture and timing telemetry, while preserving external 10 MHz reference and PPS support.

On the host side, I developed a customized UHD 4.10 environment and SDR++ frontend for both Windows and Linux. The application exposes RF filter bandwidth, LO offset, reference lock, PPS status, GNSS information, firmware telemetry and other board-specific controls directly from the SDR++ source panel.

One particularly interesting part of the project was making sustained 56 MS/s operation practical across both operating systems while retaining B210/UHD compatibility.

The Firmware is not open source or free, and Fabrizio is selling it for US$19.90.

Kintex-7 FPGA & custom SDR++ : 56 MHz Wideband Waterfall

Watch this video on YouTube

September 16, 2026

Bluewatch: Detecting new Bluetooth Devices in your Neighbourhood via a Raspberry Pi

Thank you to p0larpatch for writing in and sharing with us his project called "Bluewatch," which uses a Raspberry Pi to detect when new Bluetooth devices appear in your neighborhood. While Bluewatch doesn't use an SDR and only uses a standalone Raspberry Pi, it may still interest our readers. p0larpatch explains the project below:

Get alerts when new Bluetooth devices appear in your local neighbourhood.

The real strength shows up once you actually start using it: categorize the devices you already know, your own phones, your TV, the smart plugs, the neighbour's robot lawnmower, whatever's expected around you, and BlueWatch filters all of that familiar traffic out of the way.

What's left standing out is the interesting part: the moment an unrecognized device enters the radio range of whatever's running BlueWatch, it surfaces immediately instead of being buried under dozens of devices you've already triaged.

The dashboard stops being a wall of MAC addresses and turns into an actual presence radar for your surroundings. You notice the one device that doesn't belong, not the fifty that do.

Bluewatch Screenshot: Detecting Bluetooth Devices

September 1, 2026

An HTML Browser Page that Uses Display Pixel Clock EMI Leakage to Transmit VHF Morse Code

Thank you to Efe (TA1EEI) for writing in and sharing an HTML web tool he created that uses a PC monitor to transmit Morse code. The tool works by modulating the monitor's pixel clocks to intentionally generate EMI leakage in the form of a Morse code signal. It transmits at 148.5 MHz.

Efe's work appears to be a much simpler version of TrojPix, a University research project that we posted about back in July. TrojPix is a more advanced system that introduces imperceptible pixel modulations into the screen, making high-bandwidth wireless data transfer possible via monitor EMI leakage.

The GitHub project page for Efe's VHF Monitor RF Transmitter explains exactly how the project works, including the video pixel clock and how it can be modulated and transmitted wirelessly. Efe has also provided a link to a Reddit post where there is a video, and discussion.

VHF Morse Code Transmitted via an HTML Page

August 18, 2026

AntSDR T510 Pre-launch: A 1 MHz to 6 GHz SDR with 2 GHz Bandwidth and a Built-In NVIDIA Jetson

MicroPhase has just announced the pre-launch of its AntSDR T510 AI software-defined radio platform. This high-end device combines the AMD Zynq UltraScale+ RFSoC ZU47DR with an NVIDIA Jetson Orin Nano. The AMD ZU47DR RFSoC alone is already a beast, covering 1 MHz to 6 GHz, with 14-bit ADCs and 8 RX and 8 TX channels. This is a direct-sampling SDR, meaning no tuners are used, and the ADC simply samples at an extreme 5 GSPS. After the DDCs, each channel has a maximum bandwidth of up to 2 GHz, but smaller channelization can easily be achieved within the large FPGA embedded in the RFSoC.

Obviously, processing a large amount of data requires powerful computing, so the AMD ZU47DR RFSoC is combined with an NVIDIA Jetson Orin NX for real-time AI signal processing and intelligent spectrum analysis.

MicroPhase also notes that the AntSDR T510 AI will be open source, allowing developers to easily work with the hardware. It will ship with an Ubuntu 22.04 system preconfigured with CUDA, include GNURadio and SoapySDR compatibility, and include GPU-accelerated demos for real-time Wi-Fi, Bluetooth, and modulation classification using RF data captured by the platform.

This is a high-end SDR comparable to Ettus products that cost US$30k+ like the USRP X410, but Chinese manufacturers like MicroPhase may be able to bring the pricing down. The ANTSDR-T510 non-AI version without the Jetson is already available on Chinese marketplace sites for about US$5000, so with the additional $500 Jetson Orin Nano added, this version should only be a little more expensive.

August 11, 2026

ESP32 Bit Pirate Updates: New LoRa and Meshtastic Analysis Features

Back in September 2025, we posted about the "ESP32 Bus Pirate" firmware, which transforms an ESP32-S3 into a multi-protocol debugging and hacking tool. We later covered an update in March 2026 that added waterfall displays, cellular modem support, and an external radio expander.

Although the ESP32 does not have true SDR capabilities, it can leverage its numerous built-in radio hardware components to achieve a range of interesting SDR-like features. Recently, "Geo," the creator of the ESP32 Bus Pirate, wrote in to share some recent firmware updates with us.

Geo notes that the project is now called "ESP32 Bit Pirate" and now includes LoRa/SX1262 support and Meshtastic analysis features.

ESP32 Bit Pirate can now transmit and receive LoRa packets, monitor RSSI, scan frequency activity, display a simple waterfall view and perform Channel Activity Detection. Radio parameters including frequency, bandwidth, spreading factor, coding rate, transmit power, preamble and sync word can be configured directly from the interface.

Packets can also be recorded to the ESP32 filesystem and replayed later together with their original radio configuration.

A dedicated Meshtastic analysis shell has also been added, allowing users to send, receive and inspect Meshtastic packets. The goal is not to replace a Meshtastic node, but to provide a debugging and experimentation interface for understanding and interacting with LoRa/Meshtastic traffic.

The latest update has also added new LoRa hardware support for the Heltec Vision Master T190 and Heltec WiFi LoRa 32 V4, a browser-based debugging ecosystem, a Python scripting lab, and a BPIO2 USB adapter mode.

The project is entirely open source, and the code can be found on their GitHub page.