Noisey chips

Preamble

Following on from Banging noises…, I attempted to recreate the Noise Chip (U4) depicted in the LDB-1 schematic, from the article Anatomy of a drum machine. The noise chip creates both a white noise signal as well as four tuned square waves at different (unknown) frequencies. I have attempted to contact the author for more details but have not had a reply as yet.

It is using either PIC (which is likely seeing as the author states a preference for the PIC microcontrollers), or an ATtiny.  I will attempt to use a ATtiny/ATmega microcontroller.

Note that parts of this are a work in progress.

Note: The phase-correct 50% trick is possible with Timer0 on an ATtiny85, but it is not clear if it is possible with Timer1 (although Timer0 does have two channels). Atmel AVR ATtiny comparison chart

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ADSR waveform generator

Preamble

Too rushed for an amusing title…

Here are a number of ADSR circuits, taken from the fantastic Yusynth website (which I came across after reading StackExchange – Building a synthesizer with no prior experience) – in particular the Archives page.

The circuits are described within PDFs, and I drew up the corresponding schematic and board files in EagleCAD.

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The EagleCAD files available on github, although seeing as Micro$oft have just acquired Github, they may not be there for very long… Five minutes later – #movingtogitlab!

The EagleCAD files available on Gitlab: Testkins/ADSR-Waveform-generator

Quick Food

Preamble

In a rush, building that circuit/robot/quadcopter, fritzing an Arduino project, or using KiCad to place components on a PCB? But you need to eat, right?

Ditch that sandwich and bag of crisps and take 10 minutes to build a meal, from these pre-engineered designs, that will, in the long run, save you time. “How will it save me time?”, I hear you ask, interested piqued. That is because it will sit for longer in your belly, allowing you more uninterrupted hours of coding, or whatever…

Diode Ring Multiplier

Preamble

Gilbert Cell, [Diode] Ring Multiplier, or Ring Modulator, call it what you will, it is an invaluable piece of circuitry for multiplying frequencies.

MFOS Noise Toaster on veroboard

Preamble

Music From Outer Space – Noise Toaster on veroboard/stripboard, Direct link to the Noise Toaster web page, minus the pointless surrounding HTML frame fluff.

Using EagleCAD – board layout

Preamble

I have been rather successfully using EagleCAD, for designing schematics, and then Veroboard/Stripboard layouts (instead of PCB layouts).

Here are a few of the gotchas that I have found.

Note that this article covers boards only. For schematic layout issues, see EagleCAD nuances – schematics

The fat lady sings…

Preamble

The last versions of Opera, for the retired versions of OSX.

The archived versions of Opera can be found here, https://ftp.opera.com/pub/opera/desktop/… however, which one is right for you? Read on…