SMT toy

This was discussed somewhere else. I’m learning SMT soldering, and maybe you can join me so we will no longer look like monkeys putting sticks in holes.

I looked for SMT kits and the only thing I found was a sparkfun Simon game which appeared to have outdated documentation and some bad reviews. So I thought that I would design a “toy” circuit - something on which I can practice so no overtly complicated, but still useful. Also, this thing could help me learn about the process of having stuff manufactured - I’d rather blow money on a batch of 50 botched “toys” than 10x more expensive botched “upcoming mutable instruments product”.

Any idea of small musical thingies you’d want to have? The thing should not take more than 1 day to design, and no more than 1 day to write the firmware for. I’d prefer something with an AVR inside because I need practice on TQFP packages.

One example I did to practice SMT board layout: Midi events generator with 16 0-5V inputs

But then so many people are doing these “MIDI CPUs” (highly liquid, Livid, Midibox) boooooring.

Any other idea?

an gekko like arp with some leds and the arp software from the shruthi?

@fcd72, cool idea! but it’ll be battery powered, not MIDI bus powered - I’ve heard the gecko has problems with recent hardware whose MIDI output is too weak.

Digital filter (standalone version) ?
Mini sequencer arp thingy with no frills, simply 16steps & a note selector …
Maybe a waveform analyzer ?(Not hose expensive thingys, just something that displays a simple waveform on a cheap graphic display of sorts)

yeah olivier, lets resurrect the gekko line, powered with 9v battery - the mutable instruments lizard :wink:

MIDI merger to MIDI USB :D, with an 8u2 Atmel chip…

Easy… Blikinlightz midi data display!

Something like this, but in diddy SMT form, with a french twist.

Who doesn’t like Blinkinlightz!??

I second EATYone’s idea. An Usb midi interface using an atmega 8u2 would be great.

Sorry, from the requirements: and no more than 1 day to write the firmware for

8u2 firmware for a usb midi hid device is already available.

There are several firmware version made for the arduino, but I don’t see why they can’t be used standalone: hiduino or this one.

+1 for a programmable arp. There is nothing anywhere similar the gekko or cyclone

I’d have thought a USB midi interface would offer no real challenge?
Ever looked inside one? There is not much in there… And if there is already working firmware, then where is the fun in that for Olivier?

> Sorry, from the requirements: and no more than 1 day to write the firmware for

I saw that. But I imagine few of us have much of an idea what goes into coding and how long it would take?? (Although you did zip your way through the digi effects board firmware pretty quickly it seemed?)

Regarding the USB interface:

  • yes, there’s already code out there, but I have never coded USB drivers before and I will never, ever, sell a product that include something I don’t understand inside-out. So there won’t be any product with USB before I take the time to learn it properly – even if in the end I acknowledge that library X or library Y is well written and does a perfect job. I’ll never get someone else’s code and stick it on a device unless I am confident that a/ I could have done it myself ; 2/ the code is of quality/efficiency good enough to justify not writing it myself (and for that I need to have a good grasp of what it does).
  • There’s a requirement that was implicit but I forgot to mention: even if the purpose number 1 is learning, it should have some potential to be turned into a product - especially if I use this as a subject for experimenting with manufacturers. There are so many existing MIDI/USB interface, including some with superior specs (the midibox 5X thing) that I don’t see why anyone would bother with the Mutable Instrument “Metoo MIDI USB”.

I like the arp idea :slight_smile:

an arpeggiator would be nice indeed. but what can be done in one day? variable gate length?

Yeah it can be done in one day. I can add as many options as you want, but what do you want in terms of UI? In terms of board size I want the thing to be about 1/4 the size of a Shruthi digital board.

hehe i want it all! is there an easy way to make expansion possible?
you know, off board, so that one could add direct controls for things.
but generally, programmable gatelength per step would be great, pattern programming, maybe velocity, i don’t know… right now.
…time to think!

If this continues like this, the SMT toy will become a Midibox SEQ v5. With 64 knobs, USB and a VCO :slight_smile:

i just thought: sending portamento on/off for individual steps?

menu only is fine too :wink:

Ready for ridiculous?

How about a toy/game/learningtool that was kinda like Simon but instead of the random call and mimic/speed-up you play a programed melody. It was an idea I had while working on my case(it’s comparable in size to a candy machine, little smaller). The idea was that at the owner of the machine would program a melody into the device and hang it on a wall somewhere kinda inconspicuously and a passerby would notice it, insert a coin and be presented with a melody. There could be a keyboard or buttons or x/y type interface but simple and small(one my case its ribbon controls). So the player would have to play back the melody in order to get the candy/prize/location of next box to unlock/Shruthi-1 part(its the increment payment plan-you and your buddies collect and trade parts to complete a fully functioning device).There could be devices all over town all playing a different parts to one song or something. I kinda forgot about that idea until this thread. Funny.

Anyhow, it could be used by students and teachers.

@rosch. The thing is, what I am looking for is the opposite - not something I would micropolish with 32 options and this and that controllable by CC and extra CV inputs and a debug serial interface, because I know I’d want to push it and implement every possible option to fill the code space. Something that serves one function - a useful one - without needing more than, say, 4 parameters to be set, and that won’t give me the feeling it is incomplete because only 50% of the code space of the AVR is used.

Some more ideas:

  • a sine or square wave poly synth (say 4 voices). Just the raw oscs, only 2 or 3 settings (waveform, vibrato), send that to pedals / effects / your Shruthi…
  • very simple drum pattern generator, 4 instruments, each octave of a keyboard controls an instrument, each key in the octave triggers a different pattern. Only one control: tempo
  • a MIDI FX (delay, randomizer, transpose) with 16 or so preset. No edit!
  • I also like the Midi Monitor thing, though there won’t be much variety soldering 24 LEDs and resistors and shift registers…
  • Something that would be called “Captain Capybara”