Connect and Test Your Decoder

Describe the tone pattern you hear (ie, high or low?  how long? etc)

• high note for 3 secs, pause for a sec, med note for 3 secs, pause for a sec, low note for 3 secs, pause for a sec

Play Some Music

Tell a member of the teaching team what your song is (or better yet, play it for us). If you don't know the name, just decipher some of the lyrics.

• the mnamnamna song &  ?

Does this code play all the songs in all the directories of the SD card? If not, which songs does it play? How does it keep from playing the text file?

• It plays the songs directly on the SD card; it only plays file with a .mp3 or .wav extension. 

Change the 'song' code to save the current volume setting in your EEPROM and fetch and set that value during initialization.  Note that the first max_num_songs*max_name_len (in this case, 520) bytes of the EEPROM are used to store file names, so don't overwrite those. 

Learning about Interrupts

Draw us a quick sketch of what your circuit looks like.

What are the pros and cons of using this method?

• Since this is an on-off circuit, debouncing allows us to eliminate multiple pulses by implementing a time delay. The drawback is that when you are rapidly pressing a button on and off, there is a delay in processing.  

Now, take what you learned to make an interrupt driven pause function for your Barebones MP3 player!