- Sat Apr 29, 2017 5:34 pm
#194602
Hello,
I am a student and after discovering the world of analog synthesizers, I have decided to build a sequencer. I have several question and concerns as I think the rough idea is possible, but I don’t know many of the details.
Disclaimer: I have read through several Arduino forum posts, outdated Digi Key articles, and went so far as to order shift registers after following Sparkfun and Arduino basic tutorials and I am unsatisfied with my attempt outlook. I am trying to build a complete device eventually making custom PCBs and a nice aluminum faceplate for. I am here because I haven’t found concrete info on how best to build what I describe below, only basic 8 or 16 step examples. Please ask me to clarify anything you need, I really want to make this project happen.
My idea for the sequencer is to start with an array of 16 steps. Each step has a potentiometer that will sweep probably within one octave to select the note that plays for that step. The tricky part is that each step will have a total of 16 sub-steps. Each sub-step is a 4-position switch where each position causes a different note action when the sequencer reaches that sub step. This results in a sequencer that can play 16 different notes, up to 16 times for each note.
I originally planned to use an Arduino mega as the basis for this project as I have minor experience with it, using multiplexers and shift registers to take in that much data. I have made 2 schematics of this section a simplified schematic of one array with 4 switches representing 4 sub steps, and a larger version with 4 arrays of 16 switches each representing steps with each of the planned 16 sub-steps. Please find it in the Dropbox below.
But this is only at the most basic level for me. There are numerous parameters I want to have control over. These include changing the speed at which the sequencer clocks at, altering the octave at which each step play on, adding music effects like glide to some steps but not others and more. I also want a display to be able to see the visual value of the parameters. These are just input methods, but the sequencer needs to be able to provide a gate signal out to drive the sequencer, preferably also with a clock in and out as well as classic and USB midi out. And to go over the top with features I wanted to possibly expand the number of steps to 64 instead of 16, allow for saving of programed sequences, playback of multiple different sequences simultaneously to drive different synthesizers.
The further I got into features I think this project could have, the more I began to doubt that an Arduino would be the best choice for a build platform. As this is a musical instrument it needs to prioritize consistent clock speed, with the possibility of it ticking at a pretty high rate. The switch array alone will consist of 256 total sub steps, and with 4 possible positions encoded into 2 bits each, that’s 512 bits of data. I am unsure if the Arduino can handle driving all this circuitry, and even if expanding the I/O like this is the best course of action as it might not be enough for all the features I want. The more I read up on this, the more it seems that my inexperience is showing and that starting with Arduino might be too limiting, but I'm too green in the field to know for sure.
I haven’t been able to find may resources pertaining to the work I want to do. So, I would like to ask for any constructive criticism, and other thoughts on how best to do this. Specifically speaking to the base platform I should use with regard to both hardware and software. And please follow up with me if you have any questions about my beginner concept.
Overall I am unsure if this was the correct place to ask this, but I am at a bit of a loss without someone to physically talk to about this. I want to thank you for taking time to look this over, I appreciate it.
Switch array schematics: https://www.dropbox.com/sh/774v6o4uwwaq ... y198a?dl=0
Also, here are the data sheets for the Multiplexer, and Shift Registers I used.
Mux: http://www.ti.com/lit/ds/symlink/cd74hc4067.pdf
Shift register: http://www.ti.com/lit/ds/symlink/cd4021b.pdf
I am a student and after discovering the world of analog synthesizers, I have decided to build a sequencer. I have several question and concerns as I think the rough idea is possible, but I don’t know many of the details.
Disclaimer: I have read through several Arduino forum posts, outdated Digi Key articles, and went so far as to order shift registers after following Sparkfun and Arduino basic tutorials and I am unsatisfied with my attempt outlook. I am trying to build a complete device eventually making custom PCBs and a nice aluminum faceplate for. I am here because I haven’t found concrete info on how best to build what I describe below, only basic 8 or 16 step examples. Please ask me to clarify anything you need, I really want to make this project happen.
My idea for the sequencer is to start with an array of 16 steps. Each step has a potentiometer that will sweep probably within one octave to select the note that plays for that step. The tricky part is that each step will have a total of 16 sub-steps. Each sub-step is a 4-position switch where each position causes a different note action when the sequencer reaches that sub step. This results in a sequencer that can play 16 different notes, up to 16 times for each note.
I originally planned to use an Arduino mega as the basis for this project as I have minor experience with it, using multiplexers and shift registers to take in that much data. I have made 2 schematics of this section a simplified schematic of one array with 4 switches representing 4 sub steps, and a larger version with 4 arrays of 16 switches each representing steps with each of the planned 16 sub-steps. Please find it in the Dropbox below.
But this is only at the most basic level for me. There are numerous parameters I want to have control over. These include changing the speed at which the sequencer clocks at, altering the octave at which each step play on, adding music effects like glide to some steps but not others and more. I also want a display to be able to see the visual value of the parameters. These are just input methods, but the sequencer needs to be able to provide a gate signal out to drive the sequencer, preferably also with a clock in and out as well as classic and USB midi out. And to go over the top with features I wanted to possibly expand the number of steps to 64 instead of 16, allow for saving of programed sequences, playback of multiple different sequences simultaneously to drive different synthesizers.
The further I got into features I think this project could have, the more I began to doubt that an Arduino would be the best choice for a build platform. As this is a musical instrument it needs to prioritize consistent clock speed, with the possibility of it ticking at a pretty high rate. The switch array alone will consist of 256 total sub steps, and with 4 possible positions encoded into 2 bits each, that’s 512 bits of data. I am unsure if the Arduino can handle driving all this circuitry, and even if expanding the I/O like this is the best course of action as it might not be enough for all the features I want. The more I read up on this, the more it seems that my inexperience is showing and that starting with Arduino might be too limiting, but I'm too green in the field to know for sure.
I haven’t been able to find may resources pertaining to the work I want to do. So, I would like to ask for any constructive criticism, and other thoughts on how best to do this. Specifically speaking to the base platform I should use with regard to both hardware and software. And please follow up with me if you have any questions about my beginner concept.
Overall I am unsure if this was the correct place to ask this, but I am at a bit of a loss without someone to physically talk to about this. I want to thank you for taking time to look this over, I appreciate it.
Switch array schematics: https://www.dropbox.com/sh/774v6o4uwwaq ... y198a?dl=0
Also, here are the data sheets for the Multiplexer, and Shift Registers I used.
Mux: http://www.ti.com/lit/ds/symlink/cd74hc4067.pdf
Shift register: http://www.ti.com/lit/ds/symlink/cd4021b.pdf