Can I make midi music with a PIC16F873a

[Mathy Knaapen]

Hi skymask,

I'm quite new in this PIC an BASIC world. I can put some LEDs on now and that took a week for me to program. I have to learn a lot, I know....

The sound command generates the BEEP BEEP sound on one sertain frequency. Midi is playing more notes at the same time.

I searched a melody generator on the web. But in Holland there's no reseller for less than 1000 IC's!!! So I tought that PBP and a PCI could do the job. I want to play Brahms Lullaby for 5 minutes and fade out the music.

And about the double posting, there are more forums. I was looking for my first posting, but could not find it back..... Yep, I know....

There must be a way to play music with a PIC. It's just a matter of programming, right?


Mathy

[skimask]

There must be a way to play music with a PIC. It's just a matter of programming, right?
Mathy

MIDI programming with a PIC, sure...
MIDI-like generation with a PIC only, without an external MIDI-source?
Not without a good, relatively high speed A/D converter, and enough memory in the PIC, or attached to it, to send out to the A/D converter at a decent sampling rate to sound like decent music.
The key here is being able to transfer in/out of the external memory and shoot the data out to the A/D converter.

My advice...
Break it down to the lowest level you can possibly break it down to. Sure, you can light some LEDs, can you do any PWM with them? Can you create a variable duty cycle, variable frequency output on a pin? Can you make and use an interrupt driven program (something you'll need to send out audio at a specific sample rate).

Yes, (and this is the way I'd do it) you can record MP3 data to a file on a flash card and funnel that data thru a PIC out to a STA013 or VS1001k. But, I get the feeling that accessing flash cards and I2C control of a STA013 is a bit above your knowledge at the moment.

And there aren't any Melody Generator's here in North Dakota either, but I can sure get them from here:
http://www.maplin.co.uk/Search.aspx?...source=15&SD=Y
and that's across 2,500 miles of land and Xx,xxx miles of ocean.

[Mathy Knaapen]

I'll gues I'll have to buy 1000 melody generators.......

Mathy

[skimask]

I'll gues I'll have to buy 1000 melody generators.......

Mathy

Or you could do as suggested...learn PBP, learn the PIC, learn a bit of electronics, sprinkle in some other components, and eventually have exactly what you want, built by YOU, with YOUR name on it.
Nothing better than that...

[mister_e]

Depending what type of sound you want to produce... but that's nothing a PIC would be able to do.

Just record a sound you like on you computer with a decent Sound Editor software, then zoom in to see how it's made....

PIC are way too limited for complicated and rich sound, Maybe DsPIC would be enough.

[JohnH]

You want the PIC to send MIDI messages to control/play the casio synthesizer.

The MIDI signal is just control data, not audio (a serial control signal that sends note value on/off and other commands).

The signal is organized into 10 bits (start bit, 8 data bits and one stop) running at 31,250 bits per second.

Here is a link that describes the specifications and command set for the signal:

http://en.wikipedia.org/wiki/The_MIDI_1.0_Protocol

I am not sure if your PIC has a UART, it could be used to produce the serial signal. Then you would need space for the storage of the song data, and a way to enter it.

[Ioannis]

Hmm, I am a little confused as to what really Mathy wants to do.

1. Control the Casio Synthesizer with a PIC to make some music, or

2. Reproduce the music from the PIC in whole?

The second is a big-big project as other members described above.

The first is easy done in software only.

Ioannis

[gandora]

I'll gues I'll have to buy 1000 melody generators.......

Mathy

Gotta take it one step at a time. I suggest "beep beep"ing for a little bit. Then use FREQOUT command which CAN use multiple frequencies.

There are lots of ways of doing it, and not all of them are tooo complicated, and some of them wont cost you anything but time.

Experiment with FREQOUT. When I have time maybe I can give you a starting point. But for now, I have got to go to work ^^

[Mathy Knaapen]

Hi Everyone,

Thanks for the tons of input you gave on my question. I tried several of them and I'm still not to happy, but al things has to start from scrats.

I'm going to play with the FREQOUT command to see what happens. after that I give up for a little while.

Other question:
normaly the speaker is on one pin and the other on VDD (or VSS depending...)
But if I put the speaker on two pins, and invert those two pins at the same time( so 1 = + the other -), would that improve the sound quality? It's a kind of pushpulling the speakercone.... Just a wild gues.

Mathy

[skimask]

Other question:
normaly the speaker is on one pin and the other on VDD (or VSS depending...)
But if I put the speaker on two pins, and invert those two pins at the same time( so 1 = + the other -), would that improve the sound quality? It's a kind of pushpulling the speakercone.... Just a wild gues.
Mathy

It'll only be louder. A bit of info...
A square wave is comprised of a sine wave at frequency 'X' plus all odd harmonics on either side of the primary frequency. So, a square wave is fundamentally a whole lot of frequencies all rolled up into one.
Also, how do you get decent distortion from an electric guitar? You 'clip' the sine waves coming out of it, that is, flatten out the tops of the sine wave. What does the top of a square wave look like? Yep, flat, just like that clipped sine wave.
So, if you listen to a pure sine wave vs. a pure square wave, the square wave will sound more R2D2-ish, and the sine wave more pleasing.

By push-pulling a speaker vs. just pulling it...same result...crap.
Yes, you could filter the output thru a filter network and make those square waves a bit more rounded off and resemble a sine wave. It won't be pretty, but it'll work, and it'll seem a bit louder (and more annoying).

You still want to do what you said back in post #3? And that's it?