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10:Robot PU and Minions

Lesson: Robot PU Minion Chorus Quartet (4 tracks via radio channel)​

Introduction​

This lesson turns four Robot PUs into a “Minion chorus quartet”.

Each robot plays one vocal track, and the track is selected automatically from the robot’s radio channel number.

You can line up multiple Robot PUs and quickly assign them different parts by changing channel.

Knowledge:​

https://makecode.microbit.org/reference/radio

https://en.wikipedia.org/wiki/Synchronization_(computer_science)

Problem definition​

We want a simple way to coordinate multiple robots so that:

  • each Robot PU plays exactly one of 4 song parts
  • the selection is deterministic and easy to configure
  • robots can share the same code, but behave differently based on their radio channel

Basic diea of solutions​

  • 4 tracks: implement track1(), track2(), track3(), track4().
  • Channel → track mapping: use:trackIndex = robotPu.channel() % 4which maps channels to tracks like:
    • channel % 4 == 0 → track1
    • channel % 4 == 1 → track2
    • channel % 4 == 2 → track3
    • channel % 4 == 3 → track4
  • Quick assignment: use buttons to change the radio channel, then press the logo to start singing the mapped track.

Implemenation​

Copy this program into your MakeCode JavaScript editor.

Notes before you run:

  • Button A increments channel.
  • Button B decrements channel.
  • Logo starts the singing track selected by channel % 4.
  • robotPu.greet() initializes Robot PU.
function track3 () {
   music.rest(music.beat(BeatFraction.Breve))
   started = 1
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Whole))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Whole))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Whole))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Whole))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(740, music.beat(BeatFraction.Quarter))
   music.playTone(740, music.beat(BeatFraction.Quarter))
   music.playTone(659, music.beat(BeatFraction.Quarter))
   music.playTone(659, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Half))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Whole))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.rest(music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Double))
   started = 0
}

function track4 () {
   started = 1
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(554, music.beat(BeatFraction.Quarter))
   music.playTone(494, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Quarter))
   music.playTone(440, music.beat(BeatFraction.Whole))
   music.playTone(196, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(392, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(196, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(392, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(294, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(494, music.beat(BeatFraction.Half))
   music.playTone(523, music.beat(BeatFraction.Half))
   music.playTone(494, music.beat(BeatFraction.Half))
   music.playTone(440, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(262, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(392, music.beat(BeatFraction.Half))
   music.playTone(370, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.rest(music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Double))
   started = 0
}
function track1 () {
   music.rest(music.beat(BeatFraction.Breve))
   music.rest(music.beat(BeatFraction.Breve))
   music.rest(music.beat(BeatFraction.Double))
   music.rest(music.beat(BeatFraction.Whole))
   started = 1
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Whole))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Whole))
   music.playTone(220, music.beat(BeatFraction.Whole))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Whole))
   music.playTone(220, music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Whole))
   music.playTone(196, music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Double))
   music.rest(music.beat(BeatFraction.Breve))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Whole))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Whole))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(294, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(294, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(294, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.rest(music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Double))
   started = 0
}
function track2 () {
   music.rest(music.beat(BeatFraction.Breve))
   music.rest(music.beat(BeatFraction.Breve))
   started = 1
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Whole))
   music.rest(music.beat(BeatFraction.Double))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Half))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Whole))
   music.playTone(208, music.beat(BeatFraction.Half))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Whole))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Whole))
   music.playTone(208, music.beat(BeatFraction.Half))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Half))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(208, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(370, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(330, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(277, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Half))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Half))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(277, music.beat(BeatFraction.Quarter))
   music.playTone(247, music.beat(BeatFraction.Quarter))
   music.playTone(220, music.beat(BeatFraction.Quarter))
   music.rest(music.beat(BeatFraction.Whole))
})
// press button B to walk backward in circles
input.onButtonPressed(Button.B, function () {
   robotPu.changeChannel(-1)
})
// listen to radio messages for commands of key value pairs
radio.onReceivedValue(function (name, value) {
   robotPu.runKeyValueCommand(name, value)
})
// press logo button to dance using set mode
input.onLogoEvent(TouchButtonEvent.Pressed, function () {
   track = robotPu.channel() % 4
   if (track == 0) {
       track1()
   } else if (track == 1) {
       track2()
   } else if (track == 2) {
       track3()
   } else {
       track4()
   }
})
let track = 0
let started = 0
// Initialize robot by ask it to greet
robotPu.greet()

Example program can be downloaded from https://makecode.microbit.org/S24031-00421-18959-80697

Full quartet soundtrack template (Tenor / Whistle / Baritone / Bass)​

This section provides a runnable quartet “soundtrack” template (4 independent parts) using music.playTone(...).

Mapping used:

  • track = 0 = Tenor Solo (melody)
  • track = 1 = Whistle
  • track = 2 = Baritone
  • track = 3 = Bass

Tempo/time settings used:

  • music.setTempo(...) (see MIDI note below)
  • durations are expressed as milliseconds in tracksDursMs[]

To use this with the synchronization methods above:

  • Keep your existing radio handlers.
  • Fill tracksFreqs[] and tracksDursMs[] with the note sequences you want.

Continue transcription workflow (repeatable):

For each staff (Tenor/Whistle/Baritone/Bass), go measure by measure. For each measure, append to tracksFreqs[trackId] and tracksDursMs[trackId]. Use frequency 0 for rests.

robotPu.setChannel(166)
// Set your tempo here. The MIDI-extraction script below uses this BPM to convert ticks -> milliseconds.
music.setTempo(120)
music.setVolume(255)
let track = 0
let started = 0

function playTrack(freqs: number[], dursMs: number[]) {
    for (let i = 0; i < freqs.length; i++) {
        if (freqs[i] <= 0) music.rest(dursMs[i])
        else music.playTone(freqs[i], dursMs[i])
    }
}

let tracksFreqs: number[][] = [
    [0,294,330,330,294,262,330,392,330,330],
    [
        // Fill in
        0,392,392,392,392,392,392,392,392,392
    ],
    [
        // Fill in
        0,659,659,659,659,659,659,659,659,659
    ],
    [
        // Fill in
        523,523,523,523,523,523,523,523,523,523
    ]
]

let tracksDursMs: number[][] = [
    [
        5500,250,250,250,250,750,250,250,250,250
    ],
    [
        // Fill in
        4000,250,250,375,500,125,500,250,250,375
    ],
    [
        // Fill in
        2000,250,250,375,250,250,125,500,250,250
    ],
    [
        // Fill in
        250,250,375,250,250,125,500,250,250,375
    ]
]

function playSelectedTrack () {
    const n = tracksFreqs.length
    if (n <= 0) return
    const idx = ((track % n) + n) % n
    started = 1
    playTrack(tracksFreqs[idx], tracksDursMs[idx])
    started = 0
}

radio.onReceivedString(function (receivedString) {
    if (receivedString == "#puChorus") {
        playSelectedTrack()
    }
    robotPu.runStringCommand(receivedString)
})

radio.onReceivedValue(function (name, value) {
    robotPu.runKeyValueCommand(name, value)
})

input.onButtonPressed(Button.A, function () {
    track += 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onButtonPressed(Button.B, function () {
    track -= 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    playSelectedTrack()
})

You can also download from here:https://makecode.microbit.org/_fq9VkJYgY8qM

Upload to 4 robot PU’s microbit. Press the microbit button A or B to set sound track of each robot PU to 0,1,2,3.

Then load this gamepad program to gamepad’s microbit: https://makecode.microbit.org/_Lp31Ec4tXXM8

When you make the gamepad face-down, the chorus of 4 robot PU will start.

Generate freqs[] + durs[] using GenAI for any quartet song​

Simply use following prompt in Microsoft Copilot to fill in the blank of the​

let tracksFreqs: number[][] = []

let tracksDursMs: number[][] = []​

Prompts: Generate a chorus quartet about 60 seconds, similar to the Minion banana. Using javascript, pack the frequence into tracksFreqs as number[][], pack the duration into tracksDursMs as number[][]

then, copy and paste the code from Copilot outputs to replace the code above.

here is am example.

robotPu.setChannel(166)
// Set your tempo here. The MIDI-extraction script below uses this BPM to convert ticks -> milliseconds.
music.setTempo(120)
music.setVolume(255)
let track = 0
let started = 0

function playTrack(freqs: number[], dursMs: number[]) {
    for (let i = 0; i < freqs.length; i++) {
        if (freqs[i] <= 0) music.rest(dursMs[i])
        else music.playTone(freqs[i], dursMs[i])
    }
}

let tracksFreqs: number[][] = [
    // TRACK 0 — TENOR (Main Melody)
    [
        // INTRO
        523.25, 659.25, 783.99, 1046.5,
        987.77, 880.0, 783.99, 659.25,

        // THEME A
        523.25, 587.33, 659.25, 783.99,
        880.0, 783.99, 659.25, 587.33,
        659.25, 783.99, 880.0, 987.77,
        880.0, 783.99, 659.25, 523.25,

        // THEME B
        659.25, 783.99, 987.77, 1046.5,
        987.77, 880.0, 783.99, 880.0,
        987.77, 1046.5, 1174.66, 1046.5,
        987.77, 880.0, 783.99, 659.25,

        // BRIDGE
        523.25, 587.33, 659.25, 698.46,
        739.99, 698.46, 659.25, 587.33,

        // FINAL CHORUS
        523.25, 659.25, 783.99, 880.0,
        987.77, 1046.5, 987.77, 880.0,
        783.99, 659.25, 523.25, 523.25
    ],

    // TRACK 1 — WHISTLE (Counter‑Melody)
    [
        // INTRO
        0, 880.0, 987.77, 1174.66,
        1046.5, 987.77, 880.0, 0,

        // THEME A
        880.0, 987.77, 1046.5, 987.77,
        880.0, 783.99, 880.0, 987.77,
        1046.5, 1174.66, 1046.5, 987.77,
        880.0, 783.99, 880.0, 987.77,

        // THEME B
        1174.66, 1318.51, 1174.66, 1046.5,
        987.77, 880.0, 987.77, 1046.5,
        1174.66, 1318.51, 1396.91, 1318.51,
        1174.66, 1046.5, 987.77, 880.0,

        // BRIDGE
        880.0, 987.77, 1046.5, 987.77,
        880.0, 783.99, 698.46, 659.25,

        // FINAL CHORUS
        880.0, 987.77, 1046.5, 1174.66,
        1318.51, 1396.91, 1318.51, 1174.66,
        1046.5, 987.77, 880.0, 880.0
    ],

    // TRACK 2 — BARITONE (Harmony)
    [
        // INTRO
        130.81, 196.0, 261.63, 196.0,
        174.61, 220.0, 246.94, 220.0,

        // THEME A
        130.81, 164.81, 196.0, 164.81,
        146.83, 174.61, 196.0, 174.61,
        130.81, 164.81, 196.0, 164.81,
        146.83, 174.61, 196.0, 174.61,

        // THEME B
        174.61, 220.0, 261.63, 220.0,
        196.0, 246.94, 293.66, 246.94,
        174.61, 220.0, 261.63, 220.0,
        196.0, 246.94, 293.66, 246.94,

        // BRIDGE
        130.81, 146.83, 164.81, 174.61,
        196.0, 174.61, 164.81, 146.83,

        // FINAL CHORUS
        130.81, 164.81, 196.0, 220.0,
        246.94, 261.63, 246.94, 220.0,
        196.0, 164.81, 130.81, 130.81
    ],

    // TRACK 3 — BASS (Foundation)
    [
        // INTRO
        65.41, 98.0, 130.81, 98.0,
        73.42, 110.0, 146.83, 110.0,

        // THEME A
        65.41, 98.0, 65.41, 98.0,
        55.0, 82.41, 55.0, 82.41,
        43.65, 65.41, 43.65, 65.41,
        49.0, 73.42, 49.0, 73.42,

        // THEME B
        65.41, 98.0, 130.81, 98.0,
        73.42, 110.0, 146.83, 110.0,
        82.41, 123.47, 164.81, 123.47,
        98.0, 146.83, 196.0, 146.83,

        // BRIDGE
        65.41, 73.42, 82.41, 87.31,
        98.0, 87.31, 82.41, 73.42,

        // FINAL CHORUS
        65.41, 98.0, 130.81, 146.83,
        164.81, 196.0, 164.81, 146.83,
        130.81, 98.0, 65.41, 65.41
    ]
];

let tracksDursMs: number[][] = [
    // TRACK 0 — TENOR
    [
        // INTRO
        500, 500, 500, 750,
        500, 500, 500, 750,

        // THEME A
        500, 250, 250, 500,
        750, 500, 500, 500,
        250, 250, 500, 750,
        500, 500, 500, 1000,

        // THEME B
        500, 500, 750, 500,
        500, 500, 500, 500,
        500, 500, 750, 500,
        500, 500, 500, 1000,

        // BRIDGE
        500, 250, 250, 500,
        500, 500, 500, 750,

        // FINAL CHORUS
        500, 500, 500, 500,
        750, 750, 500, 500,
        500, 500, 1000, 1000
    ],

    // TRACK 1 — WHISTLE
    [
        // INTRO
        500, 250, 250, 500,
        500, 250, 250, 500,

        // THEME A
        250, 250, 500, 250,
        250, 500, 250, 250,
        500, 500, 250, 250,
        500, 250, 250, 500,

        // THEME B
        250, 250, 500, 500,
        250, 250, 500, 250,
        250, 250, 500, 500,
        500, 250, 250, 500,

        // BRIDGE
        250, 250, 500, 250,
        250, 500, 250, 500,

        // FINAL CHORUS
        250, 250, 500, 500,
        500, 500, 250, 250,
        500, 500, 750, 750
    ],

    // TRACK 2 — BARITONE
    [
        // INTRO
        1000, 500, 500, 1000,
        750, 750, 500, 1000,

        // THEME A
        1000, 500, 500, 1000,
        750, 750, 500, 1000,
        1000, 500, 500, 1000,
        750, 750, 500, 1000,

        // THEME B
        1000, 500, 500, 1000,
        750, 750, 500, 1000,
        1000, 500, 500, 1000,
        750, 750, 500, 1000,

        // BRIDGE
        750, 500, 500, 750,
        1000, 750, 500, 750,

        // FINAL CHORUS
        1000, 500, 500, 750,
        750, 1000, 750, 750,
        1000, 750, 1000, 1000
    ],

    // TRACK 3 — BASS
    [
        // INTRO
        500, 500, 750, 250,
        500, 500, 750, 250,

        // THEME A
        500, 250, 250, 500,
        500, 250, 250, 500,
        500, 250, 250, 500,
        500, 250, 250, 500,

        // THEME B
        500, 500, 750, 250,
        500, 500, 750, 250,
        500, 500, 750, 250,
        500, 500, 750, 250,

        // BRIDGE
        500, 250, 250, 500,
        500, 250, 250, 500,

        // FINAL CHORUS
        500, 500, 750, 250,
        500, 500, 750, 250,
        500, 500, 1000, 1000
    ]
];

function playSelectedTrack(trackID:number) {
    const n = tracksFreqs.length
    if (n <= 0) return
    const idx = ((trackID % n) + n) % n
    started = 1
    playTrack(tracksFreqs[idx], tracksDursMs[idx])
    started = 0
}

radio.onReceivedString(function (receivedString) {
    if (receivedString == "#puChorus") {
        playSelectedTrack(track)
    }
    robotPu.runStringCommand(receivedString)
})

radio.onReceivedValue(function (name, value) {
    robotPu.runKeyValueCommand(name, value)
})

input.onButtonPressed(Button.A, function () {
    track += 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onButtonPressed(Button.B, function () {
    track -= 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    playSelectedTrack(track)
})

Another example:

robotPu.setChannel(166)
// Set your tempo here. The MIDI-extraction script below uses this BPM to convert ticks -> milliseconds.
music.setTempo(120)
music.setVolume(255)
let track = 0
let started = 0

function playTrack(freqs: number[], dursMs: number[]) {
    for (let i = 0; i < freqs.length; i++) {
        if (freqs[i] <= 0) music.rest(dursMs[i])
        else music.playTone(freqs[i], dursMs[i])
    }
}

let tracksFreqs: number[][] = [
    // TRACK 0 — TENOR (Main goofy melody)
    [
        // INTRO
        523.25, 587.33, 659.25, 698.46,
        659.25, 587.33, 523.25, 392.00,

        // THEME A
        523.25, 659.25, 783.99, 880.0,
        783.99, 659.25, 587.33, 523.25,
        659.25, 783.99, 880.0, 987.77,
        880.0, 783.99, 659.25, 523.25,

        // THEME B (more excited)
        659.25, 698.46, 783.99, 880.0,
        987.77, 880.0, 783.99, 698.46,
        783.99, 880.0, 987.77, 1046.5,
        987.77, 880.0, 783.99, 659.25,

        // BRIDGE (curious)
        523.25, 587.33, 659.25, 698.46,
        739.99, 698.46, 659.25, 587.33,

        // FINAL CHORUS
        523.25, 659.25, 783.99, 880.0,
        987.77, 1046.5, 987.77, 880.0,
        783.99, 659.25, 523.25, 523.25
    ],

    // TRACK 1 — WHISTLE (Minion‑style silliness)
    [
        // INTRO
        0, 880.0, 987.77, 1174.66,
        1046.5, 987.77, 880.0, 0,

        // THEME A
        880.0, 987.77, 1046.5, 987.77,
        880.0, 783.99, 880.0, 987.77,
        1046.5, 1174.66, 1046.5, 987.77,
        880.0, 783.99, 880.0, 987.77,

        // THEME B
        1174.66, 1318.51, 1174.66, 1046.5,
        987.77, 880.0, 987.77, 1046.5,
        1174.66, 1318.51, 1396.91, 1318.51,
        1174.66, 1046.5, 987.77, 880.0,

        // BRIDGE
        880.0, 987.77, 1046.5, 987.77,
        880.0, 783.99, 698.46, 659.25,

        // FINAL CHORUS
        880.0, 987.77, 1046.5, 1174.66,
        1318.51, 1396.91, 1318.51, 1174.66,
        1046.5, 987.77, 880.0, 880.0
    ],

    // TRACK 2 — BARITONE (Harmony support)
    [
        // INTRO
        261.63, 329.63, 392.00, 329.63,
        293.66, 349.23, 392.00, 349.23,

        // THEME A
        261.63, 293.66, 329.63, 293.66,
        261.63, 293.66, 329.63, 293.66,
        261.63, 329.63, 392.00, 329.63,
        293.66, 349.23, 392.00, 349.23,

        // THEME B
        329.63, 392.00, 440.00, 392.00,
        349.23, 392.00, 440.00, 392.00,
        329.63, 392.00, 440.00, 392.00,
        349.23, 392.00, 440.00, 392.00,

        // BRIDGE
        261.63, 293.66, 329.63, 349.23,
        392.00, 349.23, 329.63, 293.66,

        // FINAL CHORUS
        261.63, 329.63, 392.00, 440.00,
        493.88, 523.25, 493.88, 440.00,
        392.00, 329.63, 261.63, 261.63
    ],

    // TRACK 3 — BASS (Bouncy Minion stomp)
    [
        // INTRO
        130.81, 196.0, 130.81, 196.0,
        146.83, 220.0, 146.83, 220.0,

        // THEME A
        130.81, 196.0, 130.81, 196.0,
        110.0, 164.81, 110.0, 164.81,
        98.0, 146.83, 98.0, 146.83,
        110.0, 164.81, 110.0, 164.81,

        // THEME B
        130.81, 196.0, 261.63, 196.0,
        146.83, 220.0, 293.66, 220.0,
        164.81, 246.94, 329.63, 246.94,
        196.0, 293.66, 392.00, 293.66,

        // BRIDGE
        130.81, 146.83, 164.81, 174.61,
        196.0, 174.61, 164.81, 146.83,

        // FINAL CHORUS
        130.81, 196.0, 261.63, 293.66,
        329.63, 392.00, 329.63, 293.66,
        261.63, 196.0, 130.81, 130.81
    ]
];

let tracksDursMs: number[][] = [
    // TRACK 0 — TENOR
    [
        // INTRO
        300, 300, 300, 500,
        300, 300, 300, 500,

        // THEME A
        400, 200, 200, 400,
        600, 400, 300, 300,
        200, 200, 400, 600,
        400, 300, 300, 800,

        // THEME B
        400, 300, 500, 400,
        300, 300, 300, 300,
        400, 400, 600, 400,
        300, 300, 300, 800,

        // BRIDGE
        400, 200, 200, 400,
        400, 400, 300, 500,

        // FINAL CHORUS
        400, 400, 400, 400,
        600, 600, 400, 400,
        400, 400, 800, 800
    ],

    // TRACK 1 — WHISTLE
    [
        // INTRO
        400, 200, 200, 400,
        400, 200, 200, 400,

        // THEME A
        200, 200, 400, 200,
        200, 400, 200, 200,
        400, 400, 200, 200,
        400, 200, 200, 400,

        // THEME B
        200, 200, 400, 400,
        200, 200, 400, 200,
        200, 200, 400, 400,
        400, 200, 200, 400,

        // BRIDGE
        200, 200, 400, 200,
        200, 400, 200, 400,

        // FINAL CHORUS
        200, 200, 400, 400,
        400, 400, 200, 200,
        400, 400, 600, 600
    ],

    // TRACK 2 — BARITONE
    [
        // INTRO
        800, 400, 400, 800,
        600, 600, 400, 800,

        // THEME A
        800, 400, 400, 800,
        600, 600, 400, 800,
        800, 400, 400, 800,
        600, 600, 400, 800,

        // THEME B
        800, 400, 400, 800,
        600, 600, 400, 800,
        800, 400, 400, 800,
        600, 600, 400, 800,

        // BRIDGE
        600, 400, 400, 600,
        800, 600, 400, 600,

        // FINAL CHORUS
        800, 400, 400, 600,
        600, 800, 600, 600,
        800, 600, 800, 800
    ],

    // TRACK 3 — BASS
    [
        // INTRO
        400, 400, 600, 200,
        400, 400, 600, 200,

        // THEME A
        400, 200, 200, 400,
        400, 200, 200, 400,
        400, 200, 200, 400,
        400, 200, 200, 400,

        // THEME B
        400, 400, 600, 200,
        400, 400, 600, 200,
        400, 400, 600, 200,
        400, 400, 600, 200,

        // BRIDGE
        400, 200, 200, 400,
        400, 200, 200, 400,

        // FINAL CHORUS
        400, 400, 600, 200,
        400, 400, 600, 200,
        400, 400, 800, 800
    ]
];

function playSelectedTrack(trackID:number) {
    const n = tracksFreqs.length
    if (n <= 0) return
    const idx = ((trackID % n) + n) % n
    started = 1
    playTrack(tracksFreqs[idx], tracksDursMs[idx])
    started = 0
}

radio.onReceivedString(function (receivedString) {
    if (receivedString == "#puChorus") {
        playSelectedTrack(track)
    }
    robotPu.runStringCommand(receivedString)
})

radio.onReceivedValue(function (name, value) {
    robotPu.runKeyValueCommand(name, value)
})

input.onButtonPressed(Button.A, function () {
    track += 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onButtonPressed(Button.B, function () {
    track -= 1
    basic.showNumber(((track % tracksFreqs.length) + tracksFreqs.length) % tracksFreqs.length)
})

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    playSelectedTrack(track)
})

Generate freqs[] + durs[] from the MIDI file (recommended)​

If you have Minions Banana Song.mid in the project root, you can generate paste-ready arrays directly from MIDI.

The MIDI in this repo has 4 tracks (one channel each):

Track 0: Elec. Piano (Classic) Track 1: Grand Piano Track 2: Music Box Track 3: Acoustic Gtr (Classic) Suggested mapping to the quartet parts:

Tenor Solo = Track 3 (Acoustic Gtr) Whistle = Track 2 (Music Box) Baritone = Track 0 (Elec. Piano) Bass = Track 1 (Grand Piano) Run this command locally to print arrays you can paste into tracksFreqs[] / tracksDursMs[]:

.venv/bin/python - <<'PY'
import mido

mid = mido.MidiFile('Minions Banana Song.mid')
TPB = mid.ticks_per_beat

# BPM used to convert ticks -> milliseconds.
# Keep this in sync with the MakeCode program's music.setTempo(...)
BPM = 120

def midi_note_to_freq(n: int) -> int:
    return int(round(440.0 * (2.0 ** ((n - 69) / 12.0))))

def ticks_to_ms(dt: int) -> int:
    return int(round((dt / TPB) * (60000.0 / BPM)))

def extract_monophonic(track: mido.MidiTrack):
    t=0
    active=set()
    segments=[]
    last_t=0
    def current_pitch():
        return max(active) if active else None

    for msg in track:
        t += msg.time
        if msg.type not in ('note_on','note_off'):
            continue
        if msg.type=='note_on' and msg.velocity>0:
            if t>last_t:
                p=current_pitch()
                segments.append((p, t-last_t))
                last_t=t
            active.add(msg.note)
        else:
            if t>last_t:
                p=current_pitch()
                segments.append((p, t-last_t))
                last_t=t
            active.discard(msg.note)

    freqs=[]
    durs_ms=[]
    for pitch, dt in segments:
        if dt<=0:
            continue
        f = 0 if pitch is None else midi_note_to_freq(pitch)
        freqs.append(f)
        durs_ms.append(ticks_to_ms(dt))
    return freqs, durs_ms

def js_array_int(arr):
    return '[' + ','.join(str(x) for x in arr) + ']'

mapping = {
    'TENOR': 3,
    'WHISTLE': 2,
    'BARITONE': 0,
    'BASS': 1,
}

for role, ti in mapping.items():
    freqs, durs_ms = extract_monophonic(mid.tracks[ti])
    print('\nROLE', role, 'TRACK', ti)
    print('FREQS', js_array_int(freqs))
    print('DURS_MS', js_array_int(durs_ms))
PY

Notes:

  • This extraction is monophonic (one note at a time). If a MIDI track contains chords, it will keep the highest note.
  • If you want a different mapping, swap the track numbers in mapping.

Technical explaination​

A. Why “channel % 4” works

robotPu.channel() returns the current radio group ID.

Using modulo:

  • keeps the mapping stable
  • allows you to use any channel number (0–255)
  • guarantees you always land in one of 4 tracks

This is a common technique for distributing roles among identical devices.

B. How the tracks are triggered

The code triggers tracks only when you press the logo button:

  • read robotPu.channel()
  • compute track = channel % 4
  • call track1..track4() based on the value

Buttons A/B only change the channel; they do not start singing.

C. Radio listeners

This program also registers:

  • radio.onReceivedString(...) → robotPu.runStringCommand(...)
  • radio.onReceivedValue(...) → robotPu.runKeyValueCommand(name, value)

So you can control Robot PU over radio while preparing the quartet.

Testing​

A. Single-robot test

Flash the program to one Robot PU.

Press A a few times to change channel.

Press the logo to start singing.

Verify you get different tracks when channel % 4 changes.

B. Quartet test (4 robots)

  • Flash the same program to 4 Robot PUs.

  • Set each robot to a different channel group such that channel % 4 differs:

    • Robot 1: channel 0 (track1)
    • Robot 2: channel 1 (track2)
    • Robot 3: channel 2 (track3)
    • Robot 4: channel 3 (track4)

  • Press the logo on each robot to start its part.

Tip:

  • If the track start timing matters, try counting down and pressing the logo buttons together.

Next steps​

  • Synchronize start time by radio
    • broadcast a single “START” message from a controller micro:bit
    • have all robots start their track when they receive it
  • Add choreography
    • on beat boundaries, call robotPu.dance() / robotPu.walk(...) to make the chorus look alive
  • Add a conductor UI
    • a separate micro:bit to assign channels and broadcast start/stop commands

Synchronization methods (practical options)​

When multiple robots must start a song together, there are a few common synchronization strategies. Each has tradeoffs in complexity vs accuracy.

A. Manual count-in (simplest)

  • Someone counts “3, 2, 1, go” and everyone presses the logo.

  • Works for demos, but humans introduce large timing error.

B. Radio START trigger (good)

  • A conductor micro:bit sends a single radio message like START.

  • Each robot starts when the message is received.

  • Better than humans, but there can still be small arrival-time differences between robots.

Conductor code (send START)

radio.setGroup(166)

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    radio.sendString("START")
})

Robot code (start on receive)

Paste this near the bottom of the quartet program (where radio handlers are registered).

radio.setGroup(166)

radio.onReceivedString(function (msg: string) {
    if (msg == "START") {
        // pick role and start immediately
        track = robotPu.channel() % 4
        if (track == 0) track1()
        else if (track == 1) track2()
        else if (track == 2) track3()
        else track4()
    }
})

C. Start-at-timestamp (best on micro:bit)​

  • Conductor sends a future start time such as startAt = control.millis() + 800.
  • Each robot waits until its own control.millis() reaches startAt before starting.
  • Even if radio packets arrive at slightly different times, robots still start together.

Why it’s better than START:

  • Radio packet delivery time varies. A shared future timestamp makes the start time deterministic.
  • You can also send tempo and other “settings” before the start.

Minimal conductor example:

radio.setGroup(166)

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    const startAt = control.millis() + 800
    radio.sendValue("startAt", startAt)
})

Minimal robot example:

radio.setGroup(166)
let startAt = -1

radio.onReceivedValue(function (name: string, value: number) {
    if (name == "startAt") {
        startAt = value
        control.inBackground(function () {
            while (control.millis() < startAt) {
                basic.pause(5)
            }
            track = robotPu.channel() % 4
            if (track == 0) track1()
            else if (track == 1) track2()
            else if (track == 2) track3()
            else track4()
        })
    }
})

D. Tempo/beat agreement (important)​

Even with a synchronized start, the robots can drift if they don’t share the same tempo.

  • Conductor broadcasts a tempo like bpm=120.
  • Robots call music.setTempo(bpm) before starting.

Conductor code (broadcast BPM)

radio.setGroup(166)
let bpm = 120

input.onButtonPressed(Button.A, function () {
    bpm += 5
})

input.onButtonPressed(Button.B, function () {
    bpm -= 5
})

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    bpm = Math.max(60, Math.min(200, bpm))
    radio.sendValue("bpm", bpm)

Robot code (apply BPM)

let bpm = 120

radio.onReceivedValue(function (name: string, value: number) {
    if (name == "bpm") {
        bpm = value
        music.setTempo(bpm)
    }
})

Tip:

  • If you use start-at-timestamp, send bpm first, then send startAt.

E. Resync / “bar beacons” (optional)​

For long songs, you can periodically broadcast a “bar number” or “beat number” so everyone can correct drift.

Simple pattern:

  • Conductor sends a barStartAt timestamp every bar.
  • Robots re-align to the newest barStartAt (small corrections) and continue.

Conductor code (bar beacon loop)

radio.setGroup(166)

let bpm = 120
let running = false

function barMs(): number {
    return Math.idiv(60000, bpm) * 4
}

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    running = !running
})

basic.forever(function () {
    if (!running) {
        basic.pause(50)
        return
    }

    const now = control.millis()
    const barStartAt = now + 200
    radio.sendValue("barStartAt", barStartAt)
    basic.pause(barMs())
})

Robot code (use bar beacons)

let barStartAt = -1

radio.onReceivedValue(function (name: string, value: number) {
    if (name == "barStartAt") {
        barStartAt = value
    }
})

// In your track code, check barStartAt occasionally and correct timing.
// A simple approach is to wait for barStartAt before starting the *next* phrase/bar.

Notes:

Resync is most useful if you also make your track code “bar aware” (split into phrases). For this quartet example (pre-written music.playTone(...) sequences), resync is harder unless you refactor tracks into bar-sized chunks.

F. Leader/follower (conductor) pattern​

If you want one robot to act as a “leader” instead of a separate conductor micro:bit:

  • Pick one Robot PU as leader.
  • Leader broadcasts bpm and startAt.
  • Followers listen and start.

Leader can be chosen by channel, for example:

  • if robotPu.channel() % 4 == 0 then leader

Leader snippet (broadcast)

radio.setGroup(166)
let bpm = 120

function amLeader(): boolean {
    return (robotPu.channel() % 4) == 0
}

input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    if (!amLeader()) return
    radio.sendValue("bpm", bpm)
    radio.sendValue("startAt", control.millis() + 800)
})

Followers use the same receiver logic shown above in method C/D.

Synchronized Minion chorus: one conductor + many Robot PUs​

In this pattern:

  • All Robot PUs run the same quartet code.
  • Each robot selects its part using track = robotPu.channel() % 4.
  • A conductor micro:bit starts all robots together.

A. Conductor micro:bit code (broadcast tempo + startAt)​

Flash this to your conductor (a gamepad micro:bit or any micro:bit).

radio.setGroup(166)

let bpm = 120

input.onButtonPressed(Button.A, function () {
    bpm += 5
})

input.onButtonPressed(Button.B, function () {
    bpm -= 5
})

// Press logo to start everyone together
input.onLogoEvent(TouchButtonEvent.Pressed, function () {
    bpm = Math.max(60, Math.min(200, bpm))
    radio.sendValue("bpm", bpm)

    // Start a bit in the future so all robots can receive the packet
    const startAt = control.millis() + 800
    radio.sendValue("startAt", startAt)
})

B. Robot PU code change (listen for startAt)​

Add this receiver logic to the quartet program (near the bottom where radio handlers are registered). It will start the correct track in sync.

let startAt = -1
let bpm = 120

radio.onReceivedValue(function (name: string, value: number) {
    // keep existing:
    // robotPu.runKeyValueCommand(name, value)

    if (name == "bpm") {
        bpm = value
    } else if (name == "startAt") {
        startAt = value
        control.inBackground(function () {
            // apply shared tempo before starting
            music.setTempo(bpm)

            // wait until the agreed start time
            while (control.millis() < startAt) {
                basic.pause(5)
            }

            // select the role and start that part
            track = robotPu.channel() % 4
            if (track == 0) track1()
            else if (track == 1) track2()
            else if (track == 2) track3()
            else track4()
        })
    }
})

Notes:

  • control.inBackground(...) prevents the radio callback from blocking.
  • Using startAt is more reliable than “start immediately on receive”.
  • If you already use radio.onReceivedValue for robotPu.runKeyValueCommand(...), merge the logic into one handler.

Testing checklist​

  • Flash the quartet code to all Robot PUs.
  • Set each robot’s channel so channel % 4 covers 0,1,2,3.
  • Flash the conductor code to a controller micro:bit.
  • Press logo on the conductor and confirm all robots begin together.