#!/usr/bin/env python3 """A PyQt5 GUI to simulate an Akai MPD218 MIDI controller. The actual controller has pressure-sensitive pads, so the simulation is approximate, this is only intended for testing offline without the physical controller. """ ################################################################ # Written in 2018 by Garth Zeglin # To the extent possible under law, the author has dedicated all copyright # and related and neighboring rights to this software to the public domain # worldwide. This software is distributed without any warranty. # You should have received a copy of the CC0 Public Domain Dedication along with this software. # If not, see . ################################################################ # standard Python libraries from __future__ import print_function import os, sys, struct, time, logging, functools, platform, argparse # for documentation on the PyQt5 API, see http://pyqt.sourceforge.net/Docs/PyQt5/index.html from PyQt5 import QtCore, QtGui, QtWidgets # for documentation on python-rtmidi: https://pypi.org/project/python-rtmidi/ import rtmidi # set up logger for module log = logging.getLogger('virtual_mpd218') ################################################################ class ButtonBox(QtWidgets.QMainWindow): """A custom main window which provides all GUI controls.""" def __init__( self, *args, **kwargs): super(ButtonBox,self).__init__() # create the GUI elements self.setupUi() # finish initialization self.show() # start the channel pressuretimer self.timer = QtCore.QTimer() self.timer.start(100) # units are milliseconds self.timer.timeout.connect(self.timer_tick) return # ------------------------------------------------------------------------------------------------ def setupUi(self): self.setWindowTitle("Virtual MPD218 MIDI Controller") self.resize(500, 400) self.centralwidget = QtWidgets.QWidget(self) self.setCentralWidget(self.centralwidget) self.mainLayout = QtWidgets.QHBoxLayout(self.centralwidget) self.mainLayout.setContentsMargins(-1, -1, -1, 9) # generate an array of dial widgets self.dialGrid = QtWidgets.QGridLayout() self.dials = list() for i in range(6): row = i // 2 col = i % 2 dial = QtWidgets.QDial(self.centralwidget) dial.setMinimumSize(QtCore.QSize(0, 30)) dial.setMaximum(127) self.dialGrid.addWidget(dial, row, col, 1, 1) dial.valueChanged['int'].connect(functools.partial(self.dialMoved, i)) self.dials.append(dial) # add the bank selects at the bottom of the dial grid self.controlBank = QtWidgets.QComboBox() self.padBank = QtWidgets.QComboBox() for item in ["A", "B", "C"]: self.controlBank.addItem(item) self.padBank.addItem(item) self.controlLabel = QtWidgets.QLabel() self.controlLabel.setText("CTRL BANK") self.padLabel = QtWidgets.QLabel() self.padLabel.setText("PAD BANK") self.dialGrid.addWidget(self.controlBank, 3, 0, 1, 1) self.dialGrid.addWidget(self.padBank, 3, 1, 1, 1) self.dialGrid.addWidget(self.controlLabel, 4, 0, 1, 1) self.dialGrid.addWidget(self.padLabel, 4, 1, 1, 1) self.mainLayout.addLayout(self.dialGrid) # generate a grid of buttons to represent the pads self.buttonGrid = QtWidgets.QGridLayout() self.pushbuttons = list() columns = 4 for button in range(16): row = 3 - (button // columns) col = button % columns title = str(button+1) pushButton = QtWidgets.QPushButton(self.centralwidget) pushButton.setMinimumSize(QtCore.QSize(80, 80)) self.buttonGrid.addWidget(pushButton, row, col, 1, 1) pushButton.setText(title) pushButton.pressed.connect(functools.partial(self.buttonPressed, button)) pushButton.released.connect(functools.partial(self.buttonReleased, button)) self.pushbuttons.append(pushButton) self.mainLayout.addLayout(self.buttonGrid) self.statusbar = QtWidgets.QStatusBar(self) self.setStatusBar(self.statusbar) # set up the main menu if False: self.actionQuit = QtWidgets.QAction(self) self.actionQuit.setText("Quit") self.actionQuit.setShortcut("Ctrl+Q") self.actionQuit.triggered.connect(self.quitSelected) self.menubar = QtWidgets.QMenuBar(self) self.menubar.setGeometry(QtCore.QRect(0, 0, 500, 22)) self.menubar.setNativeMenuBar(False) self.menubar.setObjectName("menubar") self.menuTitle = QtWidgets.QMenu(self.menubar) self.setMenuBar(self.menubar) self.menuTitle.addAction(self.actionQuit) self.menubar.addAction(self.menuTitle.menuAction()) self.menuTitle.setTitle("File") return # --- window and qt event processing ------------------------------------------------------------- def show_status(self, string): self.statusbar.showMessage(string) def write(self, string): """Write output to the status bar.""" self.statusbar.showMessage(string) return def quitSelected(self): self.write("User selected quit.") self.close() def closeEvent(self, event): self.write("Received window close event.") super(ButtonBox,self).closeEvent(event) # -------------------------------------------------------------------------------------------------- def buttonPressed(self, button): bankname = self.padBank.currentText() self.write("Pad %d on bank %s pressed." % (button+1, bankname)) bank = self.padBank.currentIndex() self.main.send_note_on(36 + button + 16*bank) def buttonReleased(self, button): bankname = self.padBank.currentText() self.write("Pad %d on bank %s released." % (button+1, bankname)) bank = self.padBank.currentIndex() self.main.send_note_off(36 + button + 16*bank) def dialMoved(self, dial, value): bankname = self.controlBank.currentText() self.write("Dial %d on bank %s moved to %d" % (dial+1, bankname, value)) # the MPD218 has a non-contiguous controller channel mapping bank = self.controlBank.currentIndex() if bank == 0: cc = (3, 9, 12, 13, 14, 15)[dial] else: cc = 16 + dial + 6 * (bank-1) self.main.send_controller_change(cc, value) # The MPD218 delivers channel pressure events as long as any pad is pressed. def timer_tick(self): if any((button.isDown() for button in self.pushbuttons)): self.main.send_channel_pressure(64) ################################################################ class MainApp(object): """Main application object holding any non-GUI related state.""" def __init__(self): # create the interface window self.window = ButtonBox() self.window.main = self # global state self.midiout = rtmidi.MidiOut() if platform.system() == 'Windows': for idx, name in enumerate(self.midiout.get_ports()): if 'loopMIDI' in name: log.info("Found loop MIDI input device %d: %s" % (idx, name)) self.midiout.open_port(idx) self.window.show_status("Opened MIDI output %s." % name) break if not self.midiout.is_port_open(): self.window.show_status("Virtual MIDI inputs are not currently supported on Windows, see python-rtmidi documentation.") else: self.midiout.open_virtual_port("virtual MPD218") self.window.show_status("Ready to go, sending to virtual MIDI port 'virtual MPD218'...") log.info("Opened virtual MIDI input port.") return # The MPD218 by default sends to MIDI channel 10, the General MIDI percussion channel. # 0x99 == 0x90 | 0x09, 0x90 == Note On, 0x09 == channel 10 # 0x89 == 0x80 | 0x09, 0x80 == Note Off, 0x09 == channel 10 # 0xb0 == 0xb0 | 0x09, 0x00 == Controller Change, 0x09 == channel 1 # 0xd9 == 0xd0 | 0x09, 0xd0 == Channel Pressure, 0x09 == channel 10 def send_note_on(self, note): log.debug("Note On: %d", note) self.midiout.send_message([0x99, note, 127]) def send_note_off(self, note): log.debug("Note Off: %d", note) self.midiout.send_message([0x89, note, 0]) def send_controller_change(self, number, value): log.debug("CC: %d %d", number, value) self.midiout.send_message([0xb0, number, value]) def send_channel_pressure(self, value): log.debug("CP: %d", value) self.midiout.send_message([0xd9, value]) ################################################################ def main(): # initialize the Qt system itself app = QtWidgets.QApplication(sys.argv) # create the main application controller main = MainApp() # run the event loop until the user is done log.info("Starting event loop.") sys.exit(app.exec_()) ################################################################ # Main script follows. This sequence is executed when the script is initiated from the command line. if __name__ == "__main__": parser = argparse.ArgumentParser() parser.add_argument('--debug', action='store_true', help='Enable debugging logging to console.') args = parser.parse_args() if args.debug: console_handler = logging.StreamHandler() console_handler.setLevel(logging.DEBUG) console_handler.setFormatter(logging.Formatter('%(levelname)s:%(name)s: %(message)s')) logging.getLogger().addHandler(console_handler) logging.getLogger().setLevel(logging.DEBUG) main()