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Freed Family 2009

College of Marin, California

Arduino sketch for high frequency precision sine wave tone sound synthesis

This table-based digital audio oscillator implementation illustrates a few useful techniques on 8-bit microprocessors
such as the Atmel parts supported by the Arduino/Wiring IDE.
A timer is used to establish the sample rate clock and PWM is used to output an 8-bit signal.
Human hearing has impressive frequency precision so accumulation is done on 32-bit integers.
The code is a lesson in how to used fixed point representations and careful sizing of tables as powers of 2.
This reduces the computational cost of the inner loop of the oscillator to a single 8-bit multiply, table lookup and

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