16F876 Usart Receive

[syscoder]

hi friends i search in the forum and found many examples thanks. i have pic 16f876 , 20 mhz osc and 1 led ,i have dmx512 lighting desk too and i want to dimm a led on dmxadres 1 (0-255 to led intensty) but there is some problem on this code it is not working. i found this code in the forum and made it again for my pic but couldnt find the problem.can you look to my code and say what is my problem here?or you can send other example code to receive dmx ..

' PIC 16F876 - 20MHZ OSC

DEFINE OSC 20 ' 20 MHZ OSC
DEFINE HSER_TXSTA 24h ' Enable transmit
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_SPBRG 4 ' 250 000 Baud @ 20MHz, 0.0%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically

ASM
ERRORLEVEL -306, -302
ENDASM

ADCON0 = 0
ADCON1 = 7

counter var word
idleflag var word
dummy var word
RCIF VAR BYTE
startcode var word
aminus var word
adress var word
x var word
level1 var word
adress = 1 ' My Start Adress


checkdmx:
counter = 1 ' Dummy variable
pulsin portC.7,0,counter 'Here 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"
dummy = RCREG
dummy = RCREG
SPBRG = 0
TXSTA.2 = 0
TXSTA.4 = 0
RCSTA.7 = 1
RCSTA.6 = 0
RCSTA.4 = 0
RCSTA.4 = 1

while RCIF = 0: wend
startcode = RCREG 'firs byte after break
if startcode <> 0 then checkdmx
aminus = adress -1

for x = 1 to aminus
while RCIF = 0: wend
dummy = RCREG
next x

level1 = RCREG
portC.1 = level1 'i want to dimm led on port c.1
RCSTA.7 = 0

goto checkdmx
return

[skimask]

level1 = RCREG
portC.1 = level1 'i want to dimm led on port c.1
RCSTA.7 = 0


What exactly is the line above supposed to accomplish? and/or what is portC.1 doing for you with the above program?

[syscoder]

thanks.

portc.1 is for the led i will make a led dimmer.(0-255 = %0 -%100 intensty)

but there is some problem on the code i think.

[mackrackit]

I do not see RCREG defined as a variable.

[syscoder]

thanks for your qick answer friend .
i was looking for a example code in this forum and saw many examples and wanted to make it for my pic 16F876 i have forund that code here in the forum and it was and also they said that it is working code.but can you say where is my problem on that code it is not working

http://www.picbasic.co.uk/forum/showthread.php?t=3192&highlight=dmx%2A

[sougata]

Hi,


level1 = RCREG
portC.1 = level1 'i want to dimm led on port c.1
RCSTA.7 = 0


RCREG is the hardware USART receive register (SFR). You are trying to dump its value (dimming value) to a Port PIN C.1 . You should use a PWM to achieve this. Your checkdmx routine waits for a valid address and then grabs the byte being received. Use the Hardware PWM unit to make your life easier.

[syscoder]

thanks for answer and can you say me how to use it ? i dont know cause ima new user on pbp

[skimask]

thanks.

portc.1 is for the led i will make a led dimmer.(0-255 = %0 -%100 intensty)

but there is some problem on the code i think.

You do know that you aren't going to dim anything using just portc.1 and turning it on and off. You have to use a PWM output or some sort of software driven PWM...change the duty cycle. Just sending the intensity (0-255, a byte value) to portc.1 (a bit value) isn't going to do anything for you...

And I'm done answering your multiple questions in multiple forums about the same thing...