phpoc_mansrlee
Published © GPL3+

Making Music Using a Step Motor

This project show how to turn step motors into musical instruments.

IntermediateFull instructions provided7,758
Making Music Using a Step Motor

Things used in this project

Hardware components

PHPoC Blue
PHPoC Blue
×1
PHPoC Stepper Motor Controller (S-type or T-type)
PHPoC Stepper Motor Controller (S-type or T-type)
×2
Makeblock Step Motor
×2
Makeblock XY plotter
×1
Limit Switch
DIYables Limit Switch
×1
Jumper Wires
DIYables Jumper Wires
×1
12V power adapter
×1
DC Power Jack Connector
DIYables DC Power Jack Connector
×1

Story

Read more

Code

Main task (task0.php)

PHP
<?php
 
include_once "/lib/se_step_play.php";
 
function play_marble_machine_song()
{
    global $step_play_dir;
 
    // test
    $melody1a = step_play_encode("5E2.67 4B2 4A8 4G8 4A4 4B4 4G8 4A8 5D8 R2.67 4B2 4A8 4G8 4A4 4F#4 4G8 4A8 5D8");
    $melody1b = step_play_encode("R2.67 4B2 5D8 5C8 4B4 4A4 4G8 4A8 4E8 R8 4C8 4E8 4B8 3B8 4C8 4D8 5D8 5C8  4B4 4A4 4G8 4A8 5E8");
    $melody1c = step_play_encode("R2.67 4B2 4A8 4G8 4A4 4B4 4G8 4A8 5D8 R2.67 4B2 5D8 5C8 4B4 4A4 4G8 4A8 5D8");
    $melody1d = step_play_encode("R2.67 4B2.67 4A8 5E8 R8 4B4 4A4 4G8 4F#8 4E8 R8 3B8 4C8 4F#8 4C8 4E8 4G8 4D8 4F#8 4A8 3B8 4B8 4D8 4G8 4A8 5E8");    
    
    $chord1a = step_play_encode("3E4 4E2.67 3E8 4E4 3E4 4E2.67 3E8 4E4 3G4 4G2.67 3G8 4G4 3G4 4G2.67 3G8 4G4");
    $chord1b = step_play_encode("3D4 4D2.67 3D8 4D4 3D4 4D2.67 3D8 4D4 3C4 4C2.67 3C8 4C4 3D4 4D2.67 3D8 4D4");
    $chord1c = step_play_encode("3E4 4E2.67 3E8 4E4 3E4 4E2.67 3E8 4E4 3G4 4G2.67 3G8 4G4 3G4 4G2.67 3G8 4G4");
    $chord1d = step_play_encode("3D4 4D2.67 3D8 4D4 3D4 4D2.67 3D8 4D8 3C4 4C2.67 3C8 4C4 3D4 4D2.67 3D8 4D4");     
    
    step_play_dir(+1);
    step_play_harmony($melody1a, $chord1a);
    //step_play_melody($melody1a);
    step_play_dir(-1);
    step_play_harmony($melody1b, $chord1b);
    step_play_dir(+1);
    step_play_harmony($melody1c, $chord1c);
    step_play_dir(-1);
    step_play_harmony($melody1d, $chord1d);
 
}
 
spc_reset();
spc_sync_baud(460800);
 
step_play_setup(0, 13);
step_play_setup(1, 14);
step_play_tempo(38);
 
play_marble_machine_song();
 
?>

Library <se_step_play.php>

PHP
Two libraries are required for this example. You need the default library sd_spc.php provided by the PSP library and the library se_step_play.php for step motor performance.
The library must be located in the lib folder
<?php

include_once "/lib/sd_spc.php";

$step_play_speed = 1000; // ms per bar
$step_play_dir = +1;
$step_play_sid = array(0, 0, 0, 0);

function step_play_setup($play_id, $sid, $vref = 8, $mode = "half", $accel = 10000)
{
	global $step_play_sid;

	if(spc_request_sys($sid, "get did") != "40002403")
		exit("step_play_setup: expansion not found\r\n");

	spc_request_dev($sid, "set vref stop 2");
	spc_request_dev($sid, "set vref goto $vref");
	spc_request_dev($sid, "set mode $mode");
	spc_request_dev($sid, "set accel $accel");

	$step_play_sid[$play_id] = $sid;
}

function step_play_tempo($tempo)
{
	global $step_play_speed;

	$step_play_speed = (int)(1000.0 / ($tempo / 60.0));
}

function step_play_dir($dir)
{
	global $step_play_dir;

	if($dir >= 0)
		$step_play_dir = +1;
	else
		$step_play_dir = -1;
}

function step_play_encode($score)
{
	global $step_play_speed;

	$score_array = explode(" ", $score);
	$score_count = count($score_array);

	$score_encoded = "";

	for($i = 0; $i < $score_count; $i++)
	{
		if(!($note = $score_array[$i]))
			continue;

		if(strtoupper($note[0]) == "R")
		{ /* rest */
			$dur_fp = (float)substr($note, 1);
			$dur_ms = (int)round($step_play_speed / $dur_fp);

			$score_encoded .= int2bin(0, 2);
			$score_encoded .= int2bin($dur_ms, 2);
		}
		else
		{ /* tone */
			$tone = (int)$note[0] * 12; // octave * 12

			// C  C# D  D# E  F  F# G  G# A A# B
			// 0  1  2  3  4  5  6  7  8  9 10 11

			switch(strtoupper($note[1]))
			{
				case "C":
					$tone += 0;
					break;
				case "D":
					$tone += 2;
					break;
				case "E":
					$tone += 4;
					break;
				case "F":
					$tone += 5;
					break;
				case "G":
					$tone += 7;
					break;
				case "A":
					$tone += 9;
					break;
				case "B":
					$tone += 11;
					break;
				default:
					exit("encode_score: unknown tone '" . $note[1] . "'\r\n");
					break;
			}

			if($note[2] == "#")
			{
				$tone++;
				$dur_fp = (float)substr($note, 3);
			}
			else
			if($note[2] == "b")
			{
				$tone--;
				$dur_fp = (float)substr($note, 3);
			}
			else
				$dur_fp = (float)substr($note, 2);

			$dur_ms = (int)($step_play_speed / $dur_fp);

			$octave = $tone / 12;
			$tone = $tone % 12;

			$freqA = 440.0 * pow(2, ($octave - 4));
			$freq = (int)round($freqA * pow(2, ($tone - 9) / 12.0));

			$score_encoded .= int2bin($freq, 2);
			$score_encoded .= int2bin($dur_ms, 2);
		}
	}

	return $score_encoded;
}

function step_play_melody($melody)
{
	global $step_play_dir;
	global $step_play_sid;

	while($melody)
	{
		$freq = bin2int($melody, 0, 2);
		$dur_ms = bin2int($melody, 2, 2);

		if($freq)
		{
			if($step_play_dir > 0)
				spc_request_dev($step_play_sid[0], "goto +1000000 $freq");
			else
				spc_request_dev($step_play_sid[0], "goto -1000000 $freq");
			usleep($dur_ms * 1000);
			spc_request_dev($step_play_sid[0], "stop 0");
		}
		else // zero frequency is 'rest'
			usleep($dur_ms * 1000);

		$melody = substr($melody, 4);
	}
}

function step_play_harmony($melody1, $melody2)
{
	global $step_play_dir;
	global $step_play_sid;

	$pid_st0 = pid_open("/mmap/st0");
	pid_ioctl($pid_st0, "start");

	$melody = array($melody1, $melody2);
	$melody_next_ms = array(0, 0);

	while($melody[0] || $melody[1] || $melody_next_ms[0] || $melody_next_ms[1])
	{
		for($i = 0; $i < 2; $i++)
		{
			if($melody_next_ms[$i])
			{
				if($melody_next_ms[$i] <= pid_ioctl($pid_st0, "get count"))
				{
					spc_request_dev($step_play_sid[$i], "stop 0");
					$melody_next_ms[$i] = 0;
				}
			}
			else
			{
				if($melody[$i])
				{
					$freq = bin2int($melody[$i], 0, 2);
					$dur_ms = bin2int($melody[$i], 2, 2);

					$melody[$i] = substr($melody[$i], 4);

					if($freq)
					{
						if($step_play_dir > 0)
							spc_request_dev($step_play_sid[$i], "goto +1000000 $freq");
						else
							spc_request_dev($step_play_sid[$i], "goto -1000000 $freq");
					}

					$melody_next_ms[$i] = pid_ioctl($pid_st0, "get count") + $dur_ms;
				}
			}
		}
	}

	pid_close($pid_st0);
}

?>

Credits

phpoc_man

phpoc_man

62 projects • 408 followers
srlee

srlee

3 projects • 4 followers

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