2025 One Hertz Challenge: Precise Time Ref via 1 Pulse-Per-Second GPS Signal

Our hacker [Wil Carver] has sent in his submission for the One Hertz Challenge: Precise Time Ref via 1 Pulse-Per-Second GPS Signal.

This GPS Disciplined Oscillator (GPSDO) project uses a Piezo 2940210 10 MHz crystal oscillator which is both oven-controlled (OCXO) and voltage-controlled (VCXO). The GPSDO takes the precision 1 Pulse-Per-Second (PPS) GPS signal and uses it to adjust the 10 MHz crystal oscillator until it repeatedly produces 10,000,000 cycles within one second.

[Wil] had trouble finding all the specs for the 2940210, particularly the EFC sensitivity (S), so after doing some research he did some experiments to fill in the blanks....

ATtiny-Powered Business Card Plays Cracktro Hits

https://invidious.privacyredirect.com/watch?v=YamEuNNJAxE

PCB business cards are a creative way to show your tech skills while getting your name out there. This take on a PCB business card, sent in by [VCC], tackles one of the big challenges with them: making them in such a way that they are cheap enough to not feel bad about handing them out.

These cards plug into a USB port for power and have over a dozen small LEDs that light up the stars on the front, and a small buzzer that can play over ten minutes of cracktro music. To keep the cost down, [VCC] went...

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Cells° is a creative coding framework for creating simple to complex interactive grid animations

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Name that Ware, July 2025

The Ware for July 2025 is shown below:

Thanks to FETguy and Renew Computers in San Rafael, California for contributing this ware!

Winner, Name that Ware June 2025

The Ware for June 2025 is a Gentner EFT-900A frequency shifter for radio audio applications. According to Chris Combs, “it lets two parties send and receive ‘full-range audio’, whatever that means, compressed and then decompressed via the usual 300-3500hz phone line”. Even though Per named the ware first, I will give the prize to Kienan because the response addresses the theory of operation of the ware – shifting the audio up/down by 250Hz so that low-end audio isn’t lost on analog telephone lines. I found that bit very insightful, and now I don’t look at the ware the same way...

2025 One-Hertz Challenge: Fixing The Clock That Once Synced The World

https://invidious.privacyredirect.com/watch?v=LMU0xd4oSnI

The HP 115BR is not one of the most well-known products from Hewlett-Packard. And yet, it was remarkably important nonetheless. This hardware once synced time around the world. Now, for our 2025 One-Hertz Challenge, [curiousmarc] has taken on the job of restoring it. 

The HP 115BR itself was not used alone, but in concert with the HP5060A atomic clock. The latter would output a 100 KHz reference output. It was the job of the HP 115BR to divide this frequency down to provide a superbly accurate 1-second tick.

The example on [curiousmarc]’s bench showed up in poor shape. It was “very broken,”...

Recording vintage CRTs with a modern Sony mirrorless camera

Recording vintage CRTs with a modern Sony mirrorless camera

Growing up, I remember recording CRTs with any camera was an exercise in frustration. You would either get a black bar that goes across everything, a slowly moving 'shutter' of darkness over the screen, black frame flickering, or even a variety of bright artifacts, especially when moving the camera around.

Just setting your camera's shutter speed to match the refresh rate somewhat closely is usually enough to make it at least bearable (I start at 1/60th and see what looks least...

Banana Pi BPI-F4 with Sunplus SP7350 SoC Launched for Edge Smart Applications

Banana Pi has introduced the BPI-F4, an industrial control board built around the Sunplus SP7350 System-on-Chip. The platform consists of a core board and a compatible carrier board that provides access to peripherals including a 1 GbE port, seven PCB terminal blocks, and a MIPI camera FFC connector. The board is powered by the Sunplus SP7350, […]

Raspberry Pi RP2350 A4 stepping fixes E9 GPIO Erratum, glitching bugs, introduces 2MB flash variants

The Raspberry Pi RP2350 dual-core Arm/RISC-V has gotten a new version – A4 stepping – addressing bugs and security vulnerabilities, notably the infamous E9 GPIO erratum and glitching bugs in the A2 stepping identified by the 2024 Hacking Challenge. Both RP2350A and RP2350B variants will benefit from the new stepping and be marked RP2350A0A4 and RP2350B0A4, respectively. The company also announced the availability of the 2MB flash variants, the RP2354A and RP2354B (unveiled in March 2025), that do not require flash on the board. RP2350 A4 stepping highlights: Fixes Glitching bugs identified in the 2024 Hacking Challenge. Exploits required physical...

ReSpeaker XMOS XVF3800 4-mic array board features ESP32-S3 module, also works over USB

Seeed Studio’s “ReSpeaker XMOS XVF3800 with XIAO ESP32S3” board is a 4-mic array board with XMOS XVF3800 voice processor and ESP32-S3 wireless MCU for standalone operation, but it can also be used as a USB microphone array for computers and SBCs. The Respeaker mic array family was first introduced in 2016, and new models have been launched over the years, like the ReSpeaker Core v2 and ReSpeaker Lite Series, with audio improvements and different feature sets. The ReSpeaker XMOS XVF3800 with XIAO ESP32S3 is the latest variant, and Seeed Studio claims it offers a “clearer voice capture, even in noisy...