This project was designed for 2 workshops i gave at Sonar Hong Kong, as an introduction to Arduino. It uses a standard Arduino UNO to build an 8-step 3-channel sequencer, connected to a custom PCB with an Arduino-based drum chip that has 8 drum sounds (based on the dsp-D8). Below video shows the ‘play’ mode of the sequencer, with the audio output connected to a small amplifier (BuffaloAmp).
The full slideshow with a step by step guide to this project is available below, and a zip with the code is here: sonar2018
The PCB has an Atmega328P-PU programmed as a ‘Duemilanove’ with 16MHz crystal (with the same bootloader i use in all of my projects). It has an LM386 amplifier with speaker output, and also a mini jack socket. The 8 drum inputs have internal pull-ups, and the drum sound is triggered by a falling edge (see slides). This first version does not have the RC low pass filter recommended by the dsp-D8 creator; it only has the DC blocking cap on the Atmega output pin. This results in a lower speaker volume which was better for the workshops.
A next project based on this drum chip is the BuffaloLabs Drum Kit: a simple extension to the above PCB with 4 touch pads to trigger 4 chosen drum sounds.
The 4 touch pads have a vibration switch (SW180) connected to 5V, with a 10K pull-down resistor on their output. This creates a short HIGH pulse. Also each channel has an LED to show when it is triggered. Below picture shows the back of the pad.
The 4 touch pads can be configured to play any of the 8 drum sounds by changing the connections to the female header on the drum PCB.
Hi Tom, I attended your drum sequencer workshop at Sonar in 2018. I have a renewed interest in coding, and I’m trying to get it going again. I had stored it in a bag, and lots of the wire have come undone, and I’m not familiar enough to determine where they should go myself. The slideshow embedded above currently only shows the first three pages, then all following pages are plain black. Could you upload again please so I can get the drum machine going again? Thanks in advance.