Step Sequencer
So I’m thinking about a new project to work on, and I’ve got a fairly ambitious idea: Build A Drum Sequencer
After looking around and talking with
Thinking about it, I believe that I could probably take the digital part of the x0xb0x, add or remove LEDs and buttons as needed, then rework about half of the software so it works a bit differently. Using a few resistor networks I think I could simplify the panel a bit too…
So, I think there’s a couple of (major) steps to doing this. Then I could even sell the thing in kit form. Those steps are:
· Settle on a feature set and the buttons and LEDs this will require.
· Rework the x0xb0x schematic to reflect this.
· Design a panel layout which will be usable, fit a readily available enclosure, and will allow the parts to fit around each other on the PCB.
· Order some sample PCBs and build a prototype.
· Rework the x0xb0x software to do what is needed.
· Look into selling either PCB sets w/ parts lists or full kits.
I wonder if this is within my abilities.
I think as a test I may to write some new x0xb0x software which will sort of implement this functionality, just to see if I can manage that part…
for a display, you could use a lcd panel, or perhaps a few 5×8 LED character displays… those could display the step in the horizontal, and beat/instrument triggerings as the vertical…
I actually think I’ll just need a single row of 16 LEDs for the beats, an instrument knob for instruments 0-16, etc. Think the drum synth (an 808, I think) in Rebirth.
you know what i always wanted to see? a multi part step-sequencer similar to the Korg Electribe series that is either USB or Firewire.
It would be like their EM-1 without the synth and sound parts. You would be able to assign each part w/ its own MIDI out # to control different VSTi’s and such.
is this going to be just a sequencer or is it going to have its own onboard sounds? will you make your own samples or will a person be able to load their own? i’m confused because it sounds like your trying to make a drum machine.
No sounds at all, just a sequencer. My whole point is to build something simple yet useful which can be used with (or integrated with) a 9090.
i see. this may be something that i would be interested in.
I think you’re on the right track with this one, my only concern is whether the pic will be able to deal with 16 single-note tracks. I would wager a very healthy “yes” since the 808s and 909s were doing that shit with some seriously antiquated uCs, but you never know. Aside from that, I have no question about the digital section of the x0x being a great starting point. It’s got just about the right number of buttons, LEDs, and rotary switches.
That’s the part I’m not sure of. I figure I could use the x0x as a bit of a dev platform and make it send 16 notes at a time, just to see if it’s possible…
I was also thinking (during a meeting) and what I don’t understand about MIDI is, when 16 notes are sent at once, isn’t there a bit of latency from the first to the last? Or does the synth not start the notes until the whole packet is received? Or is the data sent fast enough that it’s a non-issue? (I should build a MIDI sniffer to better understand this…)
I think that adding more buttons would just be a matter of adding more shift registers. Using the resistor networks should clean up the layout a lot, too.
My biggest concerns right now, honestly, are getting CAD software that will let me work on a board as large as the x0x’s, learning said software properly, and writing the firmware. Oh, and learning to use AutoCAD well enough to lay out the front and rear panels. The software can come later and be developed over time with the help of more experienced firmware developers.
AFAIK you’re right about the way midi works. A full message is certainly required, and some messages (realtime msgs like midi clock) are allowed to interrupt/intersperse others.
I don’t know enough about digital design to know how “maxed out” the interface of the x0x digital section is. Just bear in mind that every new parameter added can also require more bytes stored per pattern, so there’s some limitations there as well.
Yeah… That I don’t know either. The software is one thing I don’t know so well. May have to ask for help here… Maybe sometime soon (after my x0x is finished — hopefully real soon) I’ll just change the firmware to throw out 16 notes at once to various MIDI channels and see if it can handle it.
Also, I’m not sure how the note number assigning per-track would work. I’ll ruminate on that for awhile. Possibly it’s a global setting, with a modal setup, so when in that setup mode you select a track and the encoder lets you inc/dec the midi note output of that track…
I think you could have an ‘instrument setup’ mode. One picks the instrument number they want, dials the midi channel they want the note sent to in with the bank selector, then uses the 16 step keys (also labeled 0-F) to enter the particular note in hex. Sure, it’s a bit old school, but it’s no worse than using a sysex editor.
It’d be easier with an LCD display, but that adds a whole new layer of complexity to the hardware.
You and I can think in HEX, but I’d avoid that if possible. It’s far simpler for most people to think in decimal, if you have 16 buttons, you have 10, 0-9, it’ll just take three button presses instead of two (035, or 064, for instance).
True, true… And then there’s no need for a lookup table. Or hell, label them as A-G and 0-5 for the setup. Then someone could literally just pick (and see the LEDs lit for, say, E0.
Hmm, drum synths don’t typically map anything to sharps and flats, do they?
Yes, they do. HiHats, Cymbals, and Percussion are often mapped to black keys. The GM Drums spec calls for this, in fact, and many non-GM implementations follow this guideline.
There goes that idea then. ;)
Note number it is…
By the way, my idea includes the idea of a third rotary switch called INSTRUMENT SELECT, labeled 1-16.