Three Arduinos Team Up to Make 80s-Style Computer

Maker Joe built a retro-inspired personal computer called the Daisy-1, using three Arduinos to replicate the feel of 1980s home computers like the Commodore PET, Timex Sinclair 1000, and TRS-80 MC-10. An Arduino Due runs processing duties with a customised BASIC implementation, while an Arduino Uno handles audio and the beefier Arduino Mega drives 40×25 monochrome NTSC composite video at 8×8 character resolution. An ESP32 adds Wi-Fi, a feature decidedly absent from the source material. The whole machine lives inside a keyboard case, and Joe plans to release all three firmware images plus a Python-based file-transfer script for the community.

Sources: Hackaday

Canada’s CHU Shortwave Time Signal Shutting Down June 22

Canada’s CHU shortwave time signal, which has served radio-synced clock builders on 3.33 MHz, 7.85 MHz, and 14.67 MHz for decades, will go dark on June 22, 2026. In the pre-NTP era, CHU was the go-to reference for any wirelessly-updating clock project in North America. The signal encodes time via amplitude-modulated audio tones, with minute markers every second, much like WWV and WWVH in the United States. Amateur radio operators and embedded clock builders who relied on CHU for accurate timing will need to migrate to alternatives such as NTP over Wi-Fi or GPS-disciplined oscillators once the transmitter shuts down.

Sources: Hackaday

Autopsy of a Failed Vintage Carbon Resistor Reveals Decades of Degradation

CuriousMarc documented the internal failure of a multi-decade-old carbon resistor pulled from a vintage Metrix oscilloscope during a repair session. The 20 kilohm-rated component measured approximately 0.843 megohms—a 40× drift from specification. Its exterior showed no burn marks or discolouration, suggesting the fault was internal. With guidance from fellow restorer TubeTime, CuriousMarc carefully sanded through the outer body to expose an inner glass tube packed with carbon-laden material connecting to the two lead terminals. The likely failure mode was a degraded contact between the lead crimp and the carbon core, caused by decades of thermal cycling and mechanical stress.

Sources: Hackaday

ESP32-Powered Clock Reproduces the Errors of a Cognitive Screening Test

John Silvia built a functional wall clock deliberately styled after common errors seen in the clock-drawing test (CDT), a clinical screening tool for cognitive impairment. In the CDT, patients draw a clock face; cramming all numerals to one side can indicate damage to the right parietal lobe. Silvia reproduced exactly that layout in 3D-printed PLA, placing digits 1 through 12 along only the right half of the face. An ESP32-C3 microcontroller with a DS3231 RTC module drives a servo motor for the hour hand. Total idle current sits at just 160 microamps, allowing a set of AA NiMH cells to last approximately one year.

Sources: Hackaday

Radio Amateur Decodes Tianwen-2 X-Band Telemetry Ahead of Asteroid Arrival

Radio amateur Daniel Estévez used the 25-metre Dwingeloo radio telescope in the Netherlands to intercept and decode telemetry from China’s Tianwen-2 asteroid sample-return mission, which launched in May 2025 and is due to reach near-Earth asteroid 469219 Kamo‘oalewa in June 2026. The probe broadcasts X-band at 8428.19 MHz with the same fundamental modulation as Tianwen-1, though it uses concatenated coding with a frame length better suited to full Reed-Solomon codewords. The captured frames showed routine housekeeping data consistent with a low-power coast phase. Estévez’s decoder will enable granular tracking of the orbital insertion burn when it begins.

Sources: Hackaday

Overcharging Test Reveals Hydrogen Explosion Risk in LFP Battery Cells

YouTube channel host Will Prowse demonstrated what happens when a prismatic LiFePO4 (LFP) cell is overcharged for thirty minutes past 100 percent state of charge. The experiment placed a single cell inside an aquarium to allow hydrogen gas collection—which LFP chemistry produces during thermal events—then ignited it with a spark generator. Once lit, combustion sustained itself as hydrogen continuing pouring from the bulging vent. Unlike other lithium-ion chemistries, LFP does not self-generate oxygen, but hydrogen alone is volatile enough to destroy an enclosure or trigger adjacent cells into runaway. Commercial LFP installations mitigate this with hydrogen sensors, ventilation, and pressure blow-out panels.

Sources: Hackaday

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