YM2151 shield for Arduino (Page 4 of 7)

Other questions/remarks:

1/ The ym2151 seems to support panning for instruments (there is is line //CH: PAN    FL CON AMS PMS SLOT NE in the opm instruments), but the java controller doesn't display this option, I guess it's not supported in the arduino sketch or for another reason?

2/ For the BOM (bill of materials) there are at least:

- YM2151 (obviously)
- YM3012 (dac)
- 6N138 or 6N137  (optocoupler, you can use either I think). The 137 version seems to be more easily findable on ebay
- TLC2274 or MCP6004 (amp). The latest sketch from Charbot is with a TLC2274 but my shield has a MCP6004, I guess they are interchangeable in this context: http://www.me.umn.edu/labs/hmd/lab/electronics/ic.html
- I'll look later for the various resistors and condensators

3/ I see on http://www.ooishoo.org/?page_id=15 there is a SketchMDXPlayeｒ (chiptune player, the MDX is compiled from MML), has anyone tried this? I tried but didn't manage to make it connect between the windows program and the arduino
There is also this: https://github.com/zenmai/portableMDXPlayer but no info in the readme

4/ for the pitch difference (1/2 tone higher), could it be the quartz?

Last edited by garvalf (Sep 3, 2016 10:00 pm)

i might be sick, but Im thinking of building a full  knob-per-function hardware controller for this thing.    Oled display to show the Algorithm...   maybe patch memory.    Anyone interested?

@Charbot, what is the value of the oscillator you're using on your board?
Will you make and sell the PCB for your version (I've just ordered the parts)?

I'm a big fan of OSH Park for small projects. It opens things up for DIYers at a reasonable price.  At $5 per sq inch of design it works out to ~ $1.67 per board sq inch. And finding 2 other people that want a board is easier. Where as one can get better prices with larger runs,  but as you say it's hard to judge if you can break even.
Yogi

Hmm.. thats weird.   I built mine following the original japanese pdf  (the schematic and parts list is english)    Also, im pretty sure that other schematics that ive seen for this chip use a 4mhz.     Mine seems in-tune.      perhaps synthy can chime in.

what im envisioning w/ the knob controller can totally make it an independent instrument.   we'll see

Last edited by Charbot (Sep 9, 2016 9:15 pm)

Here is a quick  and dirty trick to transpose the notes.  works for me.
   on the main (first) page of the sketch; change these two subroutines by adding or subtracting the number of semitones you are off  from "note".   like this:

void handle_NoteOn(uint8_t channel, uint8_t note, uint8_t value){
        channel = channel - 1;
        NotePool.handleNote(true, channel, note -3, value); //  mine is 3 semitones above the correct note so... -3
    }

    void handle_NoteOff(uint8_t channel, uint8_t note, uint8_t value){
        channel = channel - 1;
        NotePool.handleNote(false, channel, note -3, value);  // make sure this is the same number of there will be hanging notes!!
    }

Last edited by Charbot (Sep 10, 2016 8:39 pm)

I don't think I have a better ear, when I discovered that I was using the sound to mix with other instruments (soundfont in midi), and it was obviously out of tune.

On the ym2151 datasheet, we can read this:
http://html.alldatasheet.com/html-pdf/9 … M2151.html

"clock frenqucy min 3, std 3.58 max 4 mhz" so between 3 and 4 it's ok. I don't know if the chip should be able to handle the differences but obviously it's out of tune. Maybe with 3 mhz it would be correct? Anyway, it was not supposed to be used in an orchestra, just in bar on coin-op machines...

I was looking for a solution but couldn't find one myself.
Thanks for the tune fix, I'll test this.