program DMX
'
' DMX 9 Channel PWM
'
' PIC 16F628A @20MHz
'
' Mardaso 2008
'
Const aantalkanalen as byte=9
Dim ch_count, offset, i, j, adres as Integer
Dim dat as byte[aantalkanalen]
Dim startcode, nutteloos, brk, led0, led1, led2, led3, led4, led5, led6, led7, led8 as byte
Dim counter as word
Sub procedure init_usart
SPBRG = 0x04
TXSTA.BRGH = 1
TXSTA.SYNC = 0
PIE1=0
PIE1.RCIE = 1
RCSTA.RX9 = 1
nutteloos=RCREG
nutteloos=RCREG
nutteloos=RCREG
RCSTA.CREN = 1
RCSTA.SPEN = 1
INTCON.PEIE=1
INTCON.GIE=1
End sub
sub procedure init_timer0
counter = 0 ' Initialize counter
INTCON=0
TMR0 = 160 ' load value TMR0
INTCON.GIE=1
INTCON.T0IE=1 ' Enable TMRO interrupt
INTCON.T0IF=0
end sub
Sub procedure interrupt
if INTCON.T0IF=1 then
inc(counter) ' Increment value of counter on every cycle
If counter <= led0 then
portb.4 = 1
else
portb.4 = 0
end if
If counter <= led1 then
portb.5 = 1
else
portb.5 = 0
end if
If counter <= led2 then
portb.6 = 1
else
portb.6 = 0
end if
If counter <= led3 then
portb.7 = 1
else
portb.7 = 0
end if
If counter <= led4 then
porta.0 = 1
else
porta.0 = 0
end if
If counter <= led5 then
porta.1 = 1
else
porta.1 = 0
end if
If counter <= led6 then
porta.2 = 1
else
porta.2 = 0
end if
If counter <= led7 then
porta.3 = 1
else
porta.3 = 0
end if
If counter <= led8 then
porta.4 = 1
else
porta.4 = 0
end if
if counter = 255 then ' if counter is 255, then reset counter
counter = 0
' To prevent clitches load the data at the end of the pwm cyclus
led0 = dat[0]
led1 = dat[1]
led2 = dat[2]
led3 = dat[3]
led4 = dat[4]
led5 = dat[5]
led6 = dat[6]
led7 = dat[7]
led8 = dat[8]
end if
TMR0 = 160 ' load value TMR0
INTCON.T0IE=1 ' Enable TMRO interrupt
INTCON.T0IF=0
portb.3=0
end if
'Uart interrupt routine
if PIR1.RCIF=1 then
portb.3=1
if (RCSTA.OERR) then
RCSTA.SPEN=0
RCSTA.SPEN=1
nutteloos=RCREG
nutteloos=RCREG
nutteloos=RCREG
RCSTA.CREN=0
RCSTA.CREN=1
ch_count=0
brk=0
else
if (RCSTA.FERR) then
nutteloos=RCREG
ch_count=0
offset=0
brk=0xFF
else
if (brk = 0xFF) then
if (ch_count=0) then
startcode=RCREG
else
if (adres<1) then
nutteloos = RCREG
for j=0 to aantalkanalen-1
dat[j]=0
next j
else
' ------------------------------ Hier adres controleren en evt. uitlezen
if (ch_count >= adres) and (ch_count < (adres + aantalkanalen)) and (startcode = 0) then
dat[offset] = RCREG
offset= offset + 1
else
nutteloos = RCREG
end if
' ------------------------------
end if
end if
ch_count = ch_count + 1
else
nutteloos = RCREG
ch_count = 0
end if
end if
end if
PIR1.RCIF=0
end if
end sub
main:
TRISA = 0xE0 ' PORTA is output
PORTA = 0x00 ' Initialize PORTA
TRISB = 0x02 ' PORTB is output
PORTB = 0x00 ' Initialize PORTB
CMCON = 0x07 ' comperators off
OPTION_REG = $80 ' Assign prescaler to TMR0
'
' Option register
' bit <2:0> | Timer0 prescaler Rate
'---------------------------------------
' 000 | 1:2
' 001 | 1:4
' 010 | 1:8
' 011 | 1:16
' 100 | 1:32
' 101 | 1:64
' 110 | 1:128
' 111 | 1:256
'---------------------------------------
PORTB.0 = 0 ' Set SN75176 to recieve data
PORTB.3 = 1
ch_count=0
brk=0
for j=0 to aantalkanalen-1
dat[j] = 0
next j
init_timer0
init_usart
counter = 0 ' Initialize counter
while TRUE
adres = 1
'
wend
end.
