Detecting Audio Transients (Example and Free Cross-Platform Software)

Wikipedia defines an audio transient as "a high amplitude, short-duration sound at the beginning of a waveform that occurs in phenomena such as musical sounds, noises or speech". Here's an example that points out the transients in a short snippet of audio:

Waveform with Transients Annotated

So, a transient is just a peak that occur…

Date: March 11th, 2017 at 11:02am
Author: Terence Darwen
Tags: Audio Software, Cross-Platform Development, Transient Detection, Digital Signal Processing, DSP, C++

Using Dual MCP23S17 I/O Expander Chips with the Tiva LaunchPad

In a post a few weeks ago I showed how I had been using an I/O expander chip with the Texas Instruments Tiva LaunchPad to provide eight additional inputs using a single serial connection. I've managed to increase this to 32 inputs.

Tiva LaunchPad and Dual MCP23S17 Chips Annotated

I did this by using dual MCP23S17 I/O expander chips as shown in t…

Date: March 1st, 2017 at 8:43pm
Author: Terence Darwen
Tags: Embedded, Tiva LaunchPad, TM4C123G, ARM Cortex-M4, Microchip MCP23S17, I/O Expander, Synth Project

My Awesome Phase Vocoder (Audio Examples and Free Software Download)

I've been spending a good amount of time working on a phase vocoder lately. I'm happy to say I have an early working demo version that sounds quite good.

Piano Waveform Stretched and Compressed

The phase vocoder allows for stretching and compressing the time duration of audio (as shown in the waveforms above) without changing the pitch…

Date: February 14th, 2017 at 9:42pm
Author: Terence Darwen
Tags: Audio Software, Cross-Platform Development, Phase Vocoder, Digital Signal Processing, DSP, C++

Using Embedded Artists' LabTool with My Tiva LaunchPad

Lately I've been working with using I/O expanders in conjunction with my Texas Instruments Tiva LaunchPad. The Tiva LaunchPad has a limited number of I/O pins and I'm trying to increase the number by using I/O expander chips.

Tiva LaunchPad and LabTool

I came across this YouTube video which shows how to use an MCP23S08 I/O

Date: February 7th, 2017 at 3:02pm
Author: Terence Darwen
Tags: Embedded, Tiva LaunchPad, TM4C123G, ARM-Cortex-M4, Embedded Artists, LabTool

Using a 16 Bit DAC with the Tiva LaunchPad (ARM Cortex-M4) - Video Included

I've figured out how to interface my Tiva LaunchPad with a better quality DAC (digital to analog converter). Video example:


Earlier, I'd been using a simple 8 bit DAC made from a handful of 22K resistors that sounded, well, less than optimal. I'm now using a 16 bit integrated circuit DAC…

Date: January 19th, 2017 at 7:41pm
Author: Terence Darwen
Tags: Embedded, Tiva LaunchPad, TM4C123G, ARM-Cortex-M4, 16 Bit DAC