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algorithm Arduino software

Virtual arrays using an SD card

It is common for operating systems to use a hard disk swap files to increase the amount of available system RAM by swapping blocks(or pages) of memory between real RAM and the hard drive. As many applications use RAM linearly, this imposes relatively modest decrease in performance for the bigger benefit of increased temporary RAM.

It seemed to me that, for particular applications, this concept could be applicable to providing management of arrays to increase what could be stored in a microcontroller’s very limited memory resources.

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algorithm Arduino software

Neopixel Fades and Color Transitions

Whilst updating an old application that implemented PWM color control of hard-wired RBG leds to NeoPixel type devices, I had to work out a new way to transition between colors. PWM is not an applicable technique when using serially controlled LEDs.

Here’s what resulted.

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algorithm Arduino Parola software

Parola A to Z – Handling non ASCII characters (UTF-8)

A question that I am asked on a regular basis is why particular characters in messages are not displayed ‘as-expected’ by the Parola library. These characters, often typed in from the Serial monitor or embedded within strings, contain non-ASCII characters. Here’s what is happening.

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algorithm Arduino electronics PCB software

Making music with a Yamaha YM2413 Synthesizer – Part 3

Part 1 and part 2 of this series set up the hardware and software infrastructure to support end-user applications using the YM2413 synthesizer. These are discussed in this final instalment.

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algorithm Arduino electronics PCB software

Making music with a Yamaha YM2413 Synthesizer – Part 2

The first part concluded with the YM2413 hardware and an amplifier on a test Arduino Uno shield. In this and the next part we explore the interface to the device and how to control the hardware to make music.

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algorithm Arduino electronics hardware PCB

Making music with a Yamaha YM2413 Synthesizer – Part 1

When researching material for the SN76489 sound generator (documented in these previous articles) I discovered that many early microcomputer systems incorporated both the SN76489 and a YM2413 FM synthesizer. The Yamaha synthesizer looked like an interesting piece of hardware to explore. Here’s the result.

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algorithm Arduino software

An RTTTL Parser Class

Ring Tone Text Transfer Language (RTTTL) was developed by Nokia in the 1980’s as a format and mechanism to manage ringtones on cell phones. As Nokia was leader brand at the time, this method was quickly adopted by many other manufacturers and became the de-facto standard for ringtones.

As cell phone hardware became more capable, the use of RTTTL has diminished in favour of more advanced sound production – today most ringtones are simply ordinary sound files. RTTTL files, however, are still useful in may applications.

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algorithm Arduino software

Easy Neopixel bitmaps using Excel

Digitally addressable LEDs allow you to control large numbers of LEDs using digital communication to integrated control chips that manage all the rest for you. Matrices of these LEDs can make attractive displays but it can be somewhat of a pain to create bitmaps for display.

I use an Excel worksheet to marshal the data, needing me to just fill in numbers in a worksheet matrix.

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algorithm Arduino electronics hardware software

Making noise with a SN76489 Digital Sound Generator – Part 3

In the first part and second part we examined the basics of the SN76489 hardware and the development of a library to manage sound production from this IC.

So, after all this effort, what kind of sound does this hardware produce? In this final post I run a few tests and dig into the resulting waveforms.

Categories
algorithm Arduino hardware software

Making noise with a SN76489 Digital Sound Generator – Part 2

In the first part we examined the basics of the SN76489 hardware and how to manage it at the hardware interface between MCU and IC.

To enable sound generation experiments, the first thing I did was create a library to allow me to write sketches without worrying too much about this underlying hardware management.