6 Play MIDI music

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Revision as of 03:48, 18 February 2019 by Sinovoip (talk | contribs) (Create a song of your own)
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Music

We provide a MIDI playback function module, it can be specified on the buzzer PWM output, thus playing out music, although you may not need to know this.

Well, without further nonsense, click on music, the board has been pre-connected to a built-in buzzer, its pin position is 25.

A side note: don't install a piezoelectric buzzer. It only plays a single tone.

The code is as follows (refer to the Microbit documentation for the interface)

import music
music.play(music.NYAN)

You can see the following list, which is our built-in music.

music.DADADADUM
music.ENTERTAINER
music.PRELUDE
music.ODE
music.NYAN
music.RINGTONE
music.FUNK
music.BLUES
music.BIRTHDAY
music.WEDDING
music.FUNERAL
music.PUNCHLINE
music.PYTHON
music.BADDY
music.CHASE
music.BA_DING
music.WAWAWAWAA
music.JUMP_UP
music.JUMP_DOWN
music.POWER_UP
music.POWER_DOWN

Pick some out and listen. There should be something you like

Create a song of your own

To write a list of Python [" c4:4 ", "D4", "C", "e8 "] is to write a music.

How do you understand that?

Each element can be thought of as a note whose format follows:

NOTE[octave][:duration]

The first step is to have a little basic understanding of music theory.

NOTE refers to the scale of this node. In common terms, C, D, E, F, G, A, B in music are scales. For example, "C" refers to do, so C, D, E, F, G, A, B is do, re, mi, fa, so, la xi.

Octave refers to the octave of this node, octave refers to the interval relationship. To put it simply, you sing 1, 2, 3, 4, 5, 6, 7, 1 (note: CDEFGAB for 1234567). The first one is the lower octave of the last one, and the last one is the higher octave of the first one.

Duration refers to the number of duration of notes played by the node.

For example:

"C4:4" corresponds to the note of C (Do) in the 4 (middle part), and then :4 refers to the duration of four beats, the default duration of which is 125 ms, that is, the duration of play is 0.5s.

If you name the node NOTE R then the speaker won't play any sound for the specified amount of time.

To explain this, let's look at the case in the following chapter.

extra-curricular knowledge

Music racket positioning module is the default for ticks = 4, BMP = 120, ticks refers to the beat of a note type default values, such as: 'C4 and ticks = 4, equivalent to' C4:4 ', means that the node under the benchmark of BPM broadcast duration, and BPM refers to the number of beats per minute, it is dependent on the use of electronic music the discretion of the BPM value to describe the rate of different music.

According to the formula, we can calculate the benchmark beats = 60(s) * 000/120/ ticks, and if that's the default, the beats will be 60,000/120/4 = 125 milliseconds.

Case 1: basic testing

You can look at the code and see what's going on

import music
music.play([ "C4", "D4", "E4", "F4", "G4", "A4", "B4", "C5"])
music.play([ "D1", "D2", "D3", "D4", "D5", "D6", "D7", "D8"])

Case 2: two tigers

In order to play the classic two tigers on the board, we prepared the following code.

import music
tune = ["C4:4", "D4:4", "E4:4", "C4:4", "C4:4", "D4:4", "E4:4", "C4:4",
       "E4:4", "F4:4", "G4:8", "E4:4", "F4:4", "G4:8"]
music.play(tune)

And the magic is not only that, it can further simplify the composition process, for example, the current node 'c4:4' will affect the octave configuration later, until a new replacement. So you can write it like this:

import music
tune = ["C4:4", "D", "E", "C", "C", "D", "E", "C", "E", "F", "G:8",
       "E:4", "F", "G:8"]
music.play(tune)

Does it have the same effect?

sound effect

Music lets you make non-musical sounds, like down here we've created a police siren

import music
while True:
   for freq in range(880, 1760, 16):
       music.pitch(freq, 6)
   for freq in range(1760, 880, -16):
       music.pitch(freq, 6)

Notice a little bit that the music.pitch method is an example of using it, and it requires a frequency, the frequency of 440 is the same as the frequency of a concert that is tuned.

In addition, in this case, the range function is used to generate the value of a number that defines the pitch of the pitch, the starting value, the ending value, and the gradient value. So the first range here means. Create a frequency value that starts at 880 and increases to 1760 in 16 spans, while the second range says create a 1760 that decreases to 880 in 16 spans. This allows us to make one up and one down sounds like a siren.

And finally, we used while Ture: it will let the siren go on and on. Isn't that interesting?

Ok, that's all, this chapter is over, hope you can learn something!!!

Connect your stereo

Do you find that the sound is a little bit low when playing music on the board? Here I will introduce how to connect the board to the sound system and play music with the sound system, as shown in the figure below

Music.jpg

P0 port connects the left channel or right channel of the audio line, and GND connects the GND of the audio line

Bit5.png