Design:

10/16/2022:

This is a page I made for my hardware sequencer project.

I did start this project when I was going back to school, however, working full time (60 hr night-shift weeks every other week) and school pretty much delayed my project. I wanted a 16-step MIDI to MIDI/Analog sequencer that had the following features:

Cherry MX Red key switches, a character LCD, 16 knobs to assign to CV/Gate, 6 function buttons, a rotary encoder, and MIDI In/Out/Through with also trigger outputs and MIDI out for a drum controller.

Yes, there are sequencers out there that do about as much, but I'm not a fan of rubberized buttons or super tactile keys or a weird workflow; I wanted something that felt intuitive and felt fun to play on. So I'm making my own and will be happy once I can showcase it. Stay tuned. Pun intended. In the meantime, check out my slideshow.

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My Orignal Concept And Drawing

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Started Prototyping On Stripboard PCB

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Aligning All The Cherry MX-Red Switches

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Temporarily Hot Glue-Gunned Switches In Place Until I Soldered Them

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Designed The Front Panel And Got It Professionally Made

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Initial Prototype On Breadboard Using An Atmega32 Microcontroller

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Installing Components After Fitting The Front Panel

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Designing The Main Circuit And MIDI Circuit Boards

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Got The Circuit Boards Professionally Made By ExpressPCB

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Some Assembly With My Little Helper, Smokie

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I Figure Why Not Sign The Canvas

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Boards Mostly Assembled

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DSQ Stands For Digital Sequencer

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Now More Programming And Case Design

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So far my shift registers, LCD, ADC and multiplexor, and key-encoder drivers work as expected. I was also able to sync the MIDI clock with another MIDI sequencer, so I'm confident it will work fine with my Ableton Live setup. I have not yet implemented the MIDI not output functionality, but I need a better oscilloscope for that then the one I currently have.

I did not think ahead before designing my circuit boards, so for this first proof of concept prototype I will be limited to 1 kB of non-volotile memory; this will leave me with 24 patterns (3 banks of 8 patterns). Drum tracks curently are not going to be savable, but I might come up with a solution here in the near future. My next version will have a minimum of 1 MB of SPI EEPROM. Another possiblility is to design piggy-back board that will allow me to free up the SPI inputs/outputs and use other GPIO so I can use the SPI interrupts. I'll decide later and hopefully post some videos of the operaton.