Go Down

Topic: * MP3 Shield * - Rogue Robotics rMP3 (Read 44 times) previous topic - next topic

mowcius

Does it really use all those pins?

I have not really delved into how it does what it does but I presumed that it just could use those other pins.

Isn't the communication via serial? In which case it would require 2 pins?

Also another question, I know that the LED on board (activity LED) flashes when music is playing and seems to brighten at corresponding points in the music. Is there any easy way to get audio values sent to the arduino so a visualiser could be done from it?

A bit more documentation would also be very nice :p

Mowcius

Lee Sylvester

I think the documentation is actually pretty good. I wish there was a support forum, tho ;-)

bhagman

Lee - The rMP3 only uses 2 serial pins to communicate.  The SPI port is there as an optional way to control the rMP3, but the current version of firmware (100.01) hasn't got that implemented (expect it in the next version).

You figured out how to do the serial change though.  Just cut the jumper at pins 6 (rMP3 TX) and 7 (rMP3 RX), and reroute the pads to the new pins you want to use.  (make sure you connect wires to the pads FURTHEST of the two from the Arduino header).

The change in the code should be really simple.  Wherever you see:

Code: [Select]
NewSoftSerial rmp3_serial(6, 7);

change it to (in your case):

Code: [Select]
NewSoftSerial rmp3_serial(3, 4);

(I'm assuming that you changed pin 6 on the rMP3 to pin 3, and pin 7 to pin 4).

If that doesn't work, post your code and we can see what's going on.


mowcius - sounds like either you're listening to a VBR mp3 file (wide range one too!  32 kbps -> 320 kbps) and the music has really quiet and really loud spots, or your eyes are fooling you!  The data goes directly from the card to the decoder.   So, the only effect you'd see is if the MP3 frames had different bitrates.

RE: documentation, our wikidocs have always been public, unfortunately you had to register.  I've changed it now so that you don't have to register.  Just add any comments/questions you have on any page that has a discussion.

b

Lee Sylvester

Thank you, Brett, that's awesome news. Having only two pins to worry about makes my life easier ;-)

Best,
Lee

mowcius

Quote
mowcius - sounds like either you're listening to a VBR mp3 file (wide range one too!  32 kbps -> 320 kbps) and the music has really quiet and really loud spots, or your eyes are fooling you!  The data goes directly from the card to the decoder.   So, the only effect you'd see is if the MP3 frames had different bitrates.

I was indeed! I hadn't noticed that it didn't change with non VBR files. It was only on the loud bits that I got brighter flashes...

Any chance you could do the Input/Output Interface page on the wiki? :)
The rest of the documentation does indeed look good, it has been a while since I have looked and I suppose I did not have a great look through.
I have just gone through and had a thorough read! Interesting stuff!

Now back to my previous question :)
Quote
Is there any easy way to get audio values sent to the arduino so a visualiser could be done from it?

It is not a problem if not, it would just be interesting to do it without all the extra circuitry it usually requires.

Mowcius

Go Up