'****************************************************************
'*  Name    : midiExperiment.BAS                                      *
'*  Author  : Rob Seward                                        *
'*  Notice  : Copyright (c) 2004 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 10/29/2004                                        *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
'midiDemo.bas

define OSC 20

'setup hardware serial port:
define HSER_RXSTA 90h   
define HSER_TXSTA 20h
define HSER_BAUD 31250  'midi data rate

'set ADC parameters:
DEFINE ADC_BITS     10
define ADC_CLOCK    3
DEFINE ADC_SAMPLEUS 50
adcon1 = %10000010  'standard configuration 

'constants:
serialMode      con 16468   'for LCD serial data
noteOnChan1     con 144     'midi status byte for "noteOn, channel 1"
noteOffChan1    con $80
controlChan1    con 176     'midi status byte for "continuous controller, chan 1"

'name all pins:
statusLed       var portb.7
LCDserial       var portc.4 'midi will occur on hardware portc.6
pot1Input       con 0       'analog channel for first pot
pot2Input       con 1       'and second pot
switch1         var portd.0

'declare variables:
potValue        var word
v1              var byte 
v1Prev          var byte
v2              var byte
v2Prev          var byte

'setup i/o:
output statusled
output LCDserial
TRISA = %11111111 'all analog channels set to input
'and set initial states
input switch1

high statusled
pause 500
low statusLED
serout2 lcdserial, serialmode, [12, 1] 'clear the LCD

sequence var byte[7]
i var byte
i = 0
                                    
temp var word

clock var word
clock = 0


gosub randomize     

main:
   
    
   
    adcin pot1input, potValue
    v1 = potValue/8 ' 10 bits -> 7 bits
    adcin pot2input, potValue
    v2 = potValue/8 ' 10 bits -> 7 bits
    
    
    if i >= 6 then
        i = 0
    endif
    
    hserout [noteonchan1, sequence[i] + 60, 127] 'noteOn message
    pause 250
    ' noteoff channel 1, middle A
    hserout [noteOffChan1, sequence[i] + 60, $00]  'noteOff
    i = i + 1
   
    if switch1 = 1 then
        gosub randomize
    endif
    
    if clock >= $FF then
        clock = 0
    endif
    clock = clock + 1
    

goto main 

randomize:
    for i = 0 to 6
        random temp
        sequence[i] = temp + clock;
        sequence[i] = sequence[i] // 12
        if i > 0 then
            gosub checkSequence
        endif
    next i
return

'this function assures that no pitch is repeated in the sequence
j var byte
checkSequence:
    for j = 0 to i - 1 
        
        if sequence[j] = sequence[i] then
            i = i-1
            return
        endif
    next j

return