DMX on 250000 baud receive

[syscoder]

Dear friends i have found a example in the forum.

i want to receive dmx512 signal from the tranmitter. i have an lightingdesk for dmx512 ch control. and i will build and device to receive it

i have pic 16f628 and 20 mhz osc i use mcs 2.3 and pbp2.47 for programming. i searched in the forum and saw many examples thanks for help . is this true to receive for ; İ HAVE PIC16F628 and it will be dimming 1 led

Which command we have to use here "Pulsin" or " Hserin" ? u use here pulsin


INCLUDE "modedefs.bas"

DEFINE OSC 20 ' osc for pic 16f628
DEFINE HSER_TXSTA 24h
DEFINE HSER_RCSTA 90h
DEFINE HSER_SPBRG 4
DEFINE HSER_BAUD 250000
DEFINE HSER_CLROERR 1
ASM
ERRORLEVEL -306, -302
ENDASM

CMCON = 7

' Variables diverves

counter VAR word ' Variable de travail WORD
idleflag VAR WORD
dummy VAR WORD
RCIF VAR byte
startcode VAR WORD
aminus VAR WORD
adresse_grada VAR WORD
x VAR WORD
newlevel1 VAR WORD
newlevel1 = RCREG 'This is your target channel data

adresse_grada = 20 ' my adress for exemple 20

'This next routine is called on a gosub from my main housekeeping loop:

checkdmx:

counter = 1 'just a dummy variable
pulsin portB.1,0,counter 'here I'm looking for the break signal

if counter = 0 then
idleflag = 1 'either no dmx, or break was too long to count
'return
endif


if counter < 40 then checkdmx 'watching for 'break
'if you get here, an active low pulse was detected, but it was too short.
'probably just part of the datastream. So go back and look again.

'otherwise, a valid break was found and it's time to read the start code

dummy = RCREG 'clear out any garbage which may be in the USART
dummy = RCREG
SPBRG = 0
TXSTA.2 = 0 'brgh = 0
TXSTA.4 = 0
RCSTA.7 = 1
RCSTA.6 = 0 'setting 8 bit receive mode, no parity, etc
RCSTA.4 = 0 'check the datasheet to see what all these bits do
RCSTA.4 = 1 'now, the USART is on and ready to receive

while RCIF = 0:wend 'hover here after break, before start code

startcode = RCREG 'This is the first byte received after the break

if startcode <> 0 then checkdmx 'do your own stuff here on a non-zero code

aminus = adresse_grada - 1 'address1 is my target address

for x = 1 to aminus 'set up a loop to count almost to the address
while RCIF = 0:WEND 'sit here until a byte is received
dummy = RCREG 'stash the byte somewhere unimportant
next x

newlevel1 = RCREG 'This is your target channel data
portA.2 = newlevel1 'i want dimming a LED on PORTA.2
RCSTA.7 = 0 'turn off the USART

goto checkdmx
return