Bandlimited waveforms for Teensy audio library

Table of contents

• General info
• Setup
• TODO
• Status

General info

This is an open source tool developed in Python that can generate lookup tables to be used with the Teensy Audio Library. The tool generates header files that can be included in your project to play the standard waveforms bandlimited (without harmonic frequencies above 22.05kHz).

Using these will result in a clearer tone with less distortion, but at the cost of higher flash usage. Try out the test code compareWaveform.ino found in the examples folder for a comparison between bandlimited and non-bandlimited square waves.

If you just want the header files that you can include in your project, get them from the generated_headers folder.

Setup

To run this script you'll need to have Python 3.x installed. For usage see the code examples below or run the script with the command python3 python3 blwftal --help

Code Examples

To generate a lookup table for a square wave execute: python3 blwftal --square It will generate a header file square_table.h that you can include in your Teensy audio library project who utilizes about 65k of flash

To make a lookup table that uses less flash execute: python3 blwftal --square --compact This will make a header that utilizes half the flash space of the previous one, about 32k.

Take a look in the examples folder for example how to implement with the Teensy Audio Library.

TODO

• Add an example on how to make a pulse wave with a variable duty cycle
• Add sound examples.
• --all option not implemented yet.

Status

Project is: in progress