The drum utilizes several peripheral amplifiers and Analog-to-Digital Converters (ADCs) plus an Atmel AtMega644 to produce the different sounds. A drum hit is recorded when one of three independent force transducers are triggered by vibration, depending on which one was triggered, the corresponding sound is played. Traditional dhol was modified to electronically produce three different sounds, as well as be able to record a drum sequence and have it play back, for learning purposes.
The main signal translation work is done outside of the micorontroller. By the time it reaches the Mega644, the signal was entirely digital, and from the point of view of the MCU, is nothing more than a switch being turned on and off. The MCU takes these digital signals and processes it in order to produce the three different tones.
Author:- Ajay Phadke and Eashwar Rangarajan