Grove_MP3

Grove MP3 Audio Player.
It can play mp3 file inside a SD card.
This library can drive Grove MP3 V2.0.

Rules of mp3 file

Grove MP3 has file regulation. File name and folder structure.

SD Card

• Capacity: Under 8GB.
• Filesystem: FAT16, FAT32

MP3 File

• Sampling Rate:8 / 11.025 / 12 / 16 / 22.05 / 24 / 32 / 44.1 / 48 (KHz)

Filename, Foldername

Folder should be on root of sd directory.

1. case of using "MP3" folder.

• folder name: MP3
• file name: 4 digits start from 0001(not 0000).

filename can contain other texts after 4 digits like 0001abc.mp3, 0002_def.mp3, 0003.mp3 ...

Max file number under the folder is around 3k.

2. case of using numberd folder

• folder name: 2 digits start from 01 to 99.

Folder name can contain other texts after 2 digits.
Filenames under this kind of folder should be 3 digits from 001.

One folder can contain files up to 255.

wired(obniz, {gnd, vcc, mp3_rx, mp3_tx, grove})

Connect to a module.
If you are using Grove cable,

• gnd=black
• vcc=red
• mp3_rx=white
• mp3_tx=yellow

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});

If the device has a grove interface, it can be connected with just the parameter {grove: obniz.grove0}.

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {grove: obniz.grove0});

[await] initWait()

Start and initialize a module.
It takes around 1sec.

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();

setVolume(vol)

volume should be within 0 to 31.
Defualt is 31.

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.setVolume(10);

volUp()

+1 volume.

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.volUp();

volDown()

-1 volume

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.volDown();

play(track,folder)

It play a specified mp3 file.
When you don't specify a folder name, It recognized as a file under "MP3" folder.

Examples

play(1) -> /MP3/0001.mp3

play(2,1) -> /01/002.mp3

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.setVolume(10);
mp3.play(1);

stop()

stop playing

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.setVolume(10);
mp3.play(1);
await obniz.wait(5000);
mp3.stop();

pause()

pause playing

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.setVolume(10);
mp3.play(1);
await obniz.wait(5000);
mp3.pause();

resume()

resume playing

// Javascript Example
var mp3 = obniz.wired("Grove_MP3", {gnd:0, vcc:1, mp3_rx:2, mp3_tx:3});
await mp3.initWait();
mp3.setVolume(10);
mp3.play(1);
await obniz.wait(5000);
mp3.pause();
await obniz.wait(3000);
mp3.resume();