I am very new to arduino etc. But I would like to build the O2 minipops with as one of my first “big” projects. For this I have some - I guess very nooby - questions:
is it possible to use an Arduino Mega pro instead of a nano? More memory + more Inputs = more samples + more patterns?
in the code there is this line “pinMode(14,OUTPUT); //SEQ cnt output”. But in the schematic there is nothing connected to Pin 14. So what is this for?
what is the difference between “Clock out” (D13) and “Midi” (Pin4/5)? Clock syncs the o2 with another gear (e.g. Behringer TD 3)…And what´s the job of Midi?
This is pretty old tech so the main limitation is the rather low audio resolution of the samples (which may or may not add to the “lo fi” charm.)
The Mega pro mini and whatnot do offer more than you’d get from a Nano or (its large format equivalent) the Uno. But you can’t just say “X times the inputs/memory, X times the capability.” It really depends on the way you design the system, and that involves understanding exactly what the hardware can deliver and what it cannot. Timing is important, for instance; a design that works well with five inputs won’t necessarily be twice as wonderful if you give it ten inputs. You can’t be sure unless you understand whether the system can cope with the extra load. It’s not much use having more inputs if the poor microcontroller can’t complete all of its tasks in a timely way.
There are plenty of online resources for people interested in such esoteric matters. They’re probably not the kind of thing we can do particularly well here, if only because we veer towards analogue rather than digital systems.
But if you’re asking this question that tells me you’re at the start of a very interesting journey. So I encourage you to get your hands on some Arduino boards and learn how to use them.
thank you for your elaborate answer. It was not that kind of answer I expected. But your comment is right
And you are right: I am very new to the world of mc and many things are a closed for me Blinking, switch something on of, count button presses…thats okay for me. Everything beyond that is a mystery I try to unravel stepwise.
Initially I wanted to to build this example and change the code, so I can use samples instead: GitHub - zueblin/Polaron: A DIY drum machine for the teensy microcontroller (hardware / software) I kept in touch with builder and asked for support. He said it is possible to change the code, but he can not help due having less time for such projects anymore. I should do it of my own! After scanning the code I thought to myself “hmmmm, maybe I should start with an easier project”
Then I came up with the o2 minipops. I thought this might be a better starting point - adding more sounds, edit patterns might be an easier task.
The lack of having a Nano at home made me think: is possible to use an Mega Pro instead of a Nano. Can I add just simply more buttons and samples and edit the patterns? I forgot that the timing might be a problem. So I ordered a Nano yesterday
Maybe @jackwildchurch can comment too. It seems to me that he has built some variations of the o2 and shared the circuit
So it sounds like to me you need two things basically:
A drum sequencer, and a sample player.
May i suggest a simple drum trigger and a project around a WAV Trigger? I have done work with this project, and i have also done a project with lowfi samples streaming from EEPROM. I do not recommend the latter, and do suggest considering the WAV Trigger project.
I have a tread where i discuss how i have configured bank changes so you can change “kits”, and i have developed a script that will build these kits in the format expected by the wavtrigger.
In action:
You can even use this with synth samples for more traditional sampler playback. (i have the sample playback routed through a vca/vcf which has an envelope that is triggered by an independent sequenced gate.)
Essentially, the nano is going to act as your sequencer, having it do the duty of a sample player as well might be a bit much, even for someone thats not new. Even then, its probably not the best way to accomplish sample playback. To be clear, the nano you got should be fine, its the bread and butter for this sorta thing.
thank you for your comment and your the links to your wav trigger. Sounds pretty nice
You are right, what I am looking for is a drum step-sequencer PLUS a sample player in one gear. What I need/want is very simple: an 808-ish drum sequencer playing samples, with a shuffle/swing function, 8 pattern buttons, multiple drumkits/banks. The most important part of the gear: bassdrum sample is not just a simple “boom”…by pressing x times a step button one can select the “intensity”, e.g. punchy, regular, ghost. With this function I will create a more dynamic drum pattern. In combination with the swing/shuffle the result may be awesome - close to a real a real drummer. This is my intention.
Some months ago I “designed” the user interface. But I wouldn´t indicate the state of a step button/sample with 3 leds. For some instruments more states are needed, e.g. the Hi-Hat: closed left hand, closed right hand, open, half closed (4) … or snare drum: left hand, right hand, flare, rim shot, ghost note (5). The sexyier way to indicate the state of an instrument would be using 2 LTP 305 micro-dot led displays for each step button like “1/4” (=sample 1 of 4 available samples).
I know, what I want may sound very ambitious and: yes, it is! And with my current knowledge I wont be able realize this project. So I started learning C, Arduino coding, etc…To extend my knowledge I decided to recreate “simple” audio/drum projects like the o2 or the example of little scale in my other post…and then change parameters, add leds, play with the projects and think to myself “why did they do this and that? what is this function for? can use this for my project?”
As I said: it is a very ambitious project. But I also say: this might be possible. If not now with my current knowledge & skills then later with extended knowledge. In the past I acquired some microcontrollers: Teensy 4.1, 2 x Teensy 3.6, the audio boards for both types, 2 x Arduino Uno, 2 x Arduino Mega pro,…and now the Nano I know, it is possible!
The target is to create drum patterns like this:
The dynamics, the slight imperfections, the groove, the drum rolls.
And for those who doubt that something like this is not possible to create with samples: listen to the demo track (8/13) here:
Sorry for the digress…back to topic: O2 minipop. I guess my Nano will arrive totay and I hope that I will have time the next days to recreate the o2 minipops…first without midi, sync, etc
hey hi! love this minipops drum machine project.
I’m working in something similar using a pattern generator.
This minipops machine uses PCM samples, that are played at 8khz, without any DAC, as far as i know. That’s pretty fast, as they’re read from the eeprom, right?
I wonder if I can use a DFplayer mini as SD card + sample player. What do you think? I’m afraid about latency, because there might be a big boilerplate before playing a file, as it’s mainly used as MP3 player.
Is there any drum machine you know that uses it? or something similar?
Jack, if you still browse this forum, I was wondering if you could point me in the right direction on how to get the lowest tempo to be slower than the default values. I’ve tried changing the code, but to no avail. Seems like I can’t get anything slower than about 85 BPM. If I’m not hearing wrong, your build definitely is capable of slower tempos, so there must be a way?? Can anyone help?
