Simple light toy scratchpad for Midiplus Smartpad ~$50

midiplus_controller_colortoy.py

class LED(object):
    RED=0x61
    GREEN=0x51
    BLUE=0x41
    PURPLE=0x31
    CYAN=0x21
    YELLOW=0x11
    WHITE=0x1
    OFF=0
    
    def __init__(self,row,col,index,note):
        self.index=index
        self.row,self.col,self.note=row,col,note
        self.color=-1
        self.colorTable=None    

    def getColor(self,timebase):
        if not self.colorTable:
            return self.color
        #print timebase % len(self.colorTable),self.colorTable
        return self.colorTable[timebase % len(self.colorTable) ]
        

class DeskControl(object):
    LED_COUNT=64
    def __init__(self):
        self.inf=open("/dev/midi2","rb")
        self.info=open("/dev/midi2","wb")
        self.t=threading.Thread(target=self.listen)
        self.t.daemon=True
        self.t.start()
        self.startLEDs()
        
    def startLEDs(self):
        self.leds=[]
        self.note2led=[0 for n in range(127)]
        for row in range(8):
            for col in range(8):
                index=(row*8)+col
                note=(row*16)+col
                self.note2led[note]=index
                self.leds.append( LED(row,col,index,note))
        
        self.lt=threading.Thread(target=self.ledThread)
        self.lt.daemon=True
        self.lt.start()
        
        
        
    def ledThread(self):
        while True:
            self.updateLEDs()
            time.sleep(0.1)
            
        
    def updateLEDs(self):
        ledTime=int(time.time()*10)
        msgs=[]
        for led in self.leds:
            oldc=led.color
            c=led.getColor(ledTime)
            if c!=oldc:
                #print led.index,c,led.color,led.note
                led.color=c
                #"Note: You need to change the LED color, you must send the MIDI OFF command to turn off the light before you can change the other color                
                msgs.append(chr(0x80)+chr(led.note)+chr(0)+chr(0x90)+chr(led.note)+chr(c))
        if msgs:
            #print "SEND",len(msgs)
            self.info.write("".join(msgs))
            self.info.flush()
            
    def listen(self):
        mb=[]
        self.sideButton=0
        while True:
            m=ord(self.inf.read(1))
            if not m&0x80:
                #sync
                continue
            dat1=ord(self.inf.read(1))
            dat2=0
            ch=m&0xf
            msg=m>>4
            if not (msg==0xc or msg==0xd):
                dat2=ord(self.inf.read(1))
            if (dat1 | dat2) & 0x80:
                print "Bad %x %x %x" % (m,dat1,dat2) 
                continue
            print "%d: %d, %d, %d" % (ch,msg,dat1,dat2)

            if msg==9: #note on
                if ch==15:
                    #side buttons
                    sb=dat1-112
                    if sb>=0 and sb<=8:
                        self.sideButton=sb
                                            
                    if dat1==120:
                        self.clearLEDs()
                    
                elif ch==0:
                    led=self.leds[ self.note2led[dat1] ]
                    if led.colorTable==None:
                        led.colorTable=[]
                    led.colorTable.append( self.sideButton<<4 ) # =[LED.WHITE,LED.OFF,LED.GREEN,LED.OFF,LED.BLUE,LED.BLUE,LED.OFF,LED.RED]


    def clearLEDs(self):
        for l in leds:
            l.colorTable=None
            l.color=COLOR.OFF

    def tx(self,ch,msg,dat1,dat2=None):
        m=ch|(msg<<4)
        out=chr(m)+chr(dat1)
        if dat2!=None:
            out+=chr(dat2)
        #for n in out:
        #    print "%02x" % ord(n)
        self.info.write(out)
        self.info.flush()


d=DeskControl()
while True:
    time.sleep(1000)

python 2, needs
import time,threading

oh if you want to do this cross-platform, use 'pygame' which has midi that works on windows etc as well. API-wise It's a bit different (and slower updates to LEDs than the above code)