If I understand how this thing works correctly, a trigger on Forward steps it forward and a trigger on Back steps it back. You could have some external trigger sources telling it to for instance step forward 8 times, then back 8 times, then forward again. With your mod it requires manual action to switch between forward triggers and backward triggers. What I’m thinking of still allows both forward triggers and backward ones, but also allows one to manually reverse their meaning.
2 Likes
Ahh yeah I see. Having the LEDs swing back and forth would look awesome. What about the cv outputs…I’m thinking a single cv output that cycles between the rows of pots over 16 steps rather than two outputs over 8 steps simultaneously. But would have to be switchable
Or find a way to have two clocks running at the same time a couple of steps offset
Edit: a sequential switch circuit is what I’m thinking of I guess
1 Like
If you want a 16 step sequencer there’s a description of that in zine issue #5 (for Patreon subscribers). Loosely speaking it’s the same thing but there are 16 steps connected to 16 Arduino pins instead of 8 steps and 8 buttons.
4 Likes
damn i have those printed out for personal use and i didnt notice that. thanks man.
1 Like
Added step switches! Didn’t have any SPST so just used one side of a SPDT on/on. Works as expected, cv drops to zero when the step is triggered. Only problem is turning off a step also turns off the step gate off at the step…hmmm see if I can find a way around that
1 Like
Presumably you’d just have to disconnect the 1k resistors from the pots and reconnect them upstream of the switch. But I’m planning on putting switches where you did. I think I’d find it preferable to have no step gate when the switch is off. It’s the absence of the gate, rather than the 0V CV, that tells whatever you’re driving to ignore that step.
2 Likes
The switches definitely make it more fun! Combined with forward and backwards you can get a ton of different feeling sequences without touching the pots I’ve been playing with it for the past hour lol.
I think you’re right about the gate mute, going to leave it as it is. The only thing you couldn’t do is step gate a separate envelope or whatever during a step that was turned off.
The next upgrades I’m thinking will definitely require code changes. Thinking about implementing a selection knob like the arpeggiator on an Arturia keystep:
Up
Down
Up and down
Down and up
Up2x
Down2x
Random
The simple up cycle and simple down cycle are already taken care of. Hope this is possible to do without going to an arduino mega or something
2 Likes
Mmm… Like the changes. Already noticed when playing around I wanted some more capabilities. Also muting would be nice… Like if you deselect a step, the previous elongates? So you send the same CV… Or something like that. Or just skip it completely.
In the meantime: me playing around with it, don’t mind the mess:
3 Likes
The switch is between the arduino and the pots/leds. So the arduino sends its signal but it never makes it to the pots or the CV busses. So if you hooked it up to cv on a vca it could be a mute.
In order for the switches to affect the behavior of the Arduino it’d have to be able to read their state. Problem is all the input pins are taken up. There are ways around that. It should be possible to wire up the buttons kind of like a CV keyboard so they’d only use one input pin. Or you could use a multiplexer, or use a controller with more I/O pins…
2 Likes
Sounds like there is a redesign coming up. A multiplexer is a sound approach, but this implies a software change. Maybe there are other changes people would like to incorporate (like more steps or variable end step etc.).
Why not make this new version a community effort?
5 Likes
I’m designing my version, incorporating these changes:
LMNC version has external L78L05_TO92 regulator connected to VIN, which is wrong… either 12V to VIN or external regulator to VCC. Internal regulator probably sufficient? But external is cheap and easy.
Added input protection Schottkys to ground, probably not necessary (Arduino has protection diodes) but I feel better with them there… Note LMNC version had pull down resistors between series diodes and jacks, probably not right.
Added zero gate, and switch to reverse forward/backward inputs.
Sequence length rotary switch added. (Requires change to code. To free up necessary analog input, reset switch and button 1 are connected to the same pin, since they do the same thing.)
Enable/disable switch on each stage added.
2 Likes
Can you show us a circuit diagram which incorporates your changes?
2 Likes
I will, but want to hold off until I’ve done some testing.
2 Likes
Ben Eater made a video that should explain this.
Maybe a question I have is, is it possible to gate the gates? Like give them a shorter on time? Cause I feel my summed gate isn’t triggering, because it’s constantly high… or am I missing something else? Can’t wait to see your additions… @analogoutput
1 Like
Lots of triggers together at speed always behave like gates. Unfortunately the output here is high until the next note. You could shorten it in the code. Add a delay of some sort but this would affect to output to the point that I may be too short to work with some analog devices. Capacitors and coils gum things up and take time to change state. Not a lot of time but enough to cause a persistent state a bit like pwm.
I suppose you could add an envelope to each gate and that takes us into very different waters. (Were going to need a bigger boat)
Gates are basically pulses, you know square wave stuff. You can alter the pulse width, or how long things are on vs off. This is called a duty cycle. A square wave pulse is when it is 50% on, 50% off, so a duty cycle of 50.
Visualization:
When you modulate or change this duty cycle, its called pulse width modulation or PWM. 
2 Likes
Thanks @Caustic. We use a lot of acronyms on this site. That explanation should be bookmarked for a glossary. Perhaps it’s possible : admin?
1 Like