The Pros And Cons Of Hydrofoils

October 17, 2023 by Lewin Day 24 Comments

Hydrofoils have fascinated naval architects and marine designers for years. Fitted with underwater wings, these designs traverse the waters at great speed with a minimum of drag. As with many innovative technologies, though, the use of hydrofoils is riddled with challenges that often offset the vast benefits they offer.

While hydrofoils promise a better marine transportation experience, their adoption hasn’t been smooth sailing. In this article, we’ll dive deep into the potential and pitfalls of hydrofoil designs, and look at the unique niches this technology serves today.

Continue reading “The Pros And Cons Of Hydrofoils” →

The Clock, Another Way To Modify The Sound Of A Synth Chip

October 17, 2023 by Jenny List 10 Comments

The Philips SAA1099 is perhaps one of the lesser-known among the crop of 1980s-era 8-bit sound generator chips, but with three stereo voices onboard it makes a capable instrument for chiptune experimentation. It’s attracted the attention of [Folkert van Heusden], who’s tried the novel experiment of seeing what happens when a sound chip’s clock is varied.

A quick search of the internet reveals that the chip, which appeared in early Sound Blaster cards, is intended to have an 8 MHz clock. He’s hooked it up to an Arduino as a variable clock source, which surprised us but it seems an ATmega328’s timer is faster than we expected.

There are a couple of WAV files, and as expected the clock frequency has a significant effect on the pitch. The samples just sweep up and down without much attempt at making a sound you’d want to hear, but it does raise an interesting possibility of adding a further pitch bending ability to the capabilities already in the chip. When these circuits were new we couldn’t control a clock on a whim with the 8-bit processors of the day, so of course none of us thought to try this at the time. He’s tried it, so you don’t have to.

The SAA1099 has been mentioned in these pages only once, as a chip used in peripherals for 1980s Czech computers.

Solar Camera Built From Raspberry Pi

October 17, 2023 by Richard Baguley 29 Comments

Ever since an impromptu build completed during a two-week COVID-19 quarantine back in 2020, [Will Whang] has been steadily improving his Raspberry Pi solar photography setup. It integrates a lot of cool stuff: multiple sensors, high bandwidth storage, and some serious hardware. This is no junk drawer build either, the current version uses a $2000 USD solar telescope (an LS60M with 200mm lens) and a commercial AZ-GTi mount.

He also moved up somewhat with the imaging devices from the Raspberry Pi camera module he started with to two imaging sensors of his own: the OneInchEye and the StarlightEye, both fully open source. These two sensors feed data into the Raspberry Pi 4 Compute Module, which dumps the raw images into storage.

Because solar imaging is all about capturing a larger number of images, and then processing and picking the sharpest ones, you need speed. Far more than writing to an SD Card. So, the solution [Will] came up with was to build a rather complex system that uses a CF Express to NVME adapter that can keep up, but can be quickly swapped out.

Unfortunately, all of this hard work proved to be in vain when the eclipse came, and it was cloudy in [Wills] area. But there is always another interesting solar event around the corner, and it isn’t going anywhere for a few million years. [Will] is already looking at how to upgrade the system again with the new possibilities the Raspberry Pi 5 offers.

Continue reading “Solar Camera Built From Raspberry Pi” →