Tagged: wi-fi

sdrtop Update: Wi-Fi Airtime Tools, POCSAG Pager Decoder and Native Airspy R2 Support

Earlier this month we posted about sdrtop, a Rust-based SDR bench instrument that runs in a terminal and is aimed at measurement rather than listening. Viktor László (MusiThang on GitHub) has now written in again to share several updates. Viktor notes that the goal is still to "make radio signals and the measurements behind them inspectable, rather than hiding everything behind a decoded result."

The biggest additions are new Wi-Fi tools. sdrtop can now survey 2.4 GHz channels 1 to 13 and name the least busy one, inspect a single channel frame by frame at three time scales, and show a channel's airtime use second by second. These tools need 20 Msps, so you need an SDR like the HackRF. There is also a new POCSAG pager decoder written from the ITU standard without external libraries. Viktor tested it over the air by transmitting with a HackRF and PortaPack Mayhem and receiving with an Airspy R2.

The Airspy R2 is now natively supported too. Its gain staging follows the R2's Linearity and Sensitivity gain curves, and sdrtop warns you before the tuner clips. RTL-SDRs are still fully supported, and native support for the SDRplay RSP1B and Airspy HF+ Discovery is in progress. The code is open source under the GPLv3 and available on GitHub.

Some screens from sdrtop
Some screens from sdrtop

AI Disclaimer: The project's CREDITS.md file notes that Claude Code was used for implementation, architecture discussion and problem-solving.

SLZB-Ultima: A Quad-Radio Smart Home Radio Controller Supporting Various Protocols

While not based on SDR technology, we think that some readers may be interested in this product.

We'd like to thank Serhii, who writes on behalf of SMLIGHT in Ukraine. SMLIGHT recently released its "SLZB-Ultima" device, a compact radio platform supporting multiple wireless technologies commonly used in smart homes. 

These technologies include Zigbee, Thread, Wi-Fi, and Bluetooth. The device also optionally supports Z-Wave, LTE, Power-over-Ethernet, UPS backup, infrared control, and USB-over-Ethernet. The cloud-independent software supports WireGuard VPN, Dynamic DNS, Internal Zigbee hub mode, local IF-THEN automations running directly on the device, and one-click OTA updates.

The full press release is available here in this PDF.

The device is priced affordably at only US$40 on Aliexpress.

The SLZB Ultima
The SLZB Ultima

 

Spectrum Slit: A Wall Art Display That Visualizes Wi-Fi Activity via a HackRF

Over on YouTube, RootKid, who specializes in creating engineering-based art projects, has developed an interesting wall-mounted art display panel that visualizes Wi-Fi activity by using a HackRF as the monitoring software-defined radio. The display uses a Raspberry Pi, a HackRF, and a custom-made LED light bar. The HackRF receives a 5 GHz Wi-Fi channel, and the Pi translates this into activity on the LED display, creating a visual piece that lets those around know when Wi-Fi activity is high.

The idea is to show that "we live surrounded by ghosts of our own making", which refers to the invisible storm of electromagnetic signals that we created to serve us in our modern lives.

If you are interested in other projects that combine SDR and art, you might enjoy our posts on HolyPager, Hystérésia, Signs of Life, Ghosts in the Airglow, and Open Weather.

I built a light that can see radio waves