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.


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

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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…

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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

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