12F675 RS232 software problem

[maritto]

I'm tring to send information using RS232 Software.
The problem is that when I send information, I get garbage!
I'm using a 12f675 with internal osc at 4MHz.
I just read the topic about this same issue, but there is nothing relevant, I`ve got a project almost finished, but I'm depending on this.
Here is the source code:

#include <12F675.h>
#device ADC=10
#fuses INTRC_IO,NOWDT,NOPUT,NOPROTECT,NOBROWNOUT,NOCPD,NOMCLR
#use delay(clock=4000000)
#use rs232(baud=9600,parity=N,xmit=PIN_A4,rcv=PIN_A3,bits=8)
#byte STATUS=0x03
#byte OSCCAL=0x90
#ROM 0x3FF= {0x34C0} // Calibration Word


int16 signal=0;

void adc(void){
signal=(read_adc()*0.488);
delay_us(50);
}

#INT_RA
void Serial_IN(){
char data=0;

if(kbhit())
switch((data=getch()))
{
case 'A':
putc('C');
break;

case 'B':
putc('A');
break;
}

data=input_a();
}


void main() {
int port=0;
float val=0;
//Load Factory Calibration Value Into OSCCAL
#asm
call 0x3FF
bsf STATUS,5
movwf OSCCAL
#endasm
//-------------------------------------------

setup_adc(ADC_CLOCK_INTERNAL);
setup_adc_ports(AN0_ANALOG|VSS_VREF);
set_adc_channel(0);
enable_interrupts(INT_RA3);
enable_interrupts(GLOBAL);
port=input_a();

while(true){
adc();
printf("Test\r");
delay_ms(2000);
printf("%d",(int)(signal/10));
}
}

Thanks!

[SherpaDoug]

What is your compiler version?
EXACTLY what sort of "garbage" are you getting? Can you read in hex so we have the exact bit pattern? Could the data be inverted or the wrong baud rate?
_________________
The search for better is endless. Instead simply find very good and get the job done.

[maritto]

when I simule it in proteus, it works perfectly!, but, when I connect the circuit to the Serial Com1, I just send garbage.
The baud rate, is exactly the same (the programmed, and the spected).
Using that code, in proteus worked, but when I use the circuit (the PIC works), using the MAX232 interface, It doesn't work!

It seems to repeat in some kind of patron, but it's not the information that I send, i think that the number of bits recibed it's rigth, for example:
printf("Test\n"); (I recibe)-> Usüt (something like that)

thanks![/u]

[PCM programmer]

I tested the program shown below and it works OK. It displays the
following output in the terminal window on a PC:

[maritto]

Thanks, then I'll try this, lets see if it works!

[asmboy]

you mean you can implement soft RS-232 in that part and STILL have room enuf for a flea to dance in the code space thats left - with all 4 free GPIOS's
at your disposal ? HOW MUCH code SPACE IS Left to do something with after the soft RS232 is set up ?

i never even dreamed of trying that !!!
nice

[PCM programmer]

Here is the report from the .LST file for the short program I posted
earlier in this thread.

[maritto]

OK! I've been working a lot! I'm traying to install Linux jejeje.
I tried tha pice of code, but it continues sending garbage!
I don't know why!
I need to send:

"temp;temp_ref;delay"

just that, and recibe a code
'A', or 'S'
to ask for data, or setting temp_ref

It is a project, a temperature controlator.
This is sad! I hope you can helpme!

[asmboy]

based on the Us..t response you read - i am pretty confident that the problem is baud rate related - maybe framing - either in your Pic program or on the receiving end - but probably on the receiving side

you really need to use a KNOWN working serial source to test your receiving program settings -BEFORE working with your pic
AND BTW YOU ARE using a max 232 or 222 or similar part to make the EIA RS-232 level interface - RIGHT ??if NOT using the proper interface level shifter ALL BETS ARE OFF anyway. you never talked about your hardware did you ?

any cheesy windows terminal program and a null modem cable - will let you work out for sure what the receiving baud rate really is - so long as you test first with a KNOWN baud rate you plan to use with the pic

only when you are SURE of your receive terminal status should you revisit the PIC code - i just tried this with the same part you are using - and found it to be no problem.

verifying your receiver settings before you start with a new untested source device is serial com course level 100 stuff - so to solve this - all you have to do is get with the program - ok ?

[maritto]

Yes! I'm using a max232, and the circuit, also the interface (serial cable and circuit), is tested, I succesfuly used it with a Pic16F877, probably there is an error with the software terminal, I'll try to check it's configuration, I'm using the serial port monitor utility.
Witch is the recomended baud rate?
Could you showme an example of configuration (number of bits! could it be the problem?! I'm setting it to 8)

Thanks for your help!

[maritto]

It's working!!!!
I'm really sorry, the voltage was wrong!
And the max 232, was sending garbage!
Now it works!
THANKS A LOT for you help!
Also I learned a lot about RS232 in my research to solve this problem!Thanks again!

Your help was very usefull.

[ricardjc]

[PCM programmer]

Start with a small test program, as shown in this post:
http://www.ccsinfo.com/forum/viewtopic.php?t=25737&start=2

If it doesn't work, then:

1. Post your test program.

2. Post your compiler version.