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PICman
Joined: 02 Nov 2007
Posts: 26
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| PIC16F88 cannot read RS232 |
 Posted: Mon Dec 01, 2008 4:20 pm |
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Hi...
I have a problem with a PIC16F88 and the #int_RDA interrupt.
I configured the PIC for 9600,8,N and while I can send (without any
problem) data out from the microcontroller, I have no reaction from it
when I send RS232 data into it.
My code:
| Code: |
//
// PIC16F88
//
// RA3 = RXD
// RA1 = TXD
//
// _________ _________
// __| \/ |__
// DEL debug |__|Ra2 41 Ra1|__| 9600 bps --->---
// __| |__
// --->-- 9600 bps |__|Ra3 40 Ra0|__|
// __| |__
// |__|Ra4 clkin|__| 11,0592 MHz in
// __|____ |__
// +5V|__|MCLR/Vpp clkout|__|
// __| |__
// 0V|__|Vss Vdd|__| +5V
// __| |__
// |__|Rb0/int Rb7/ICSPDAT|__|
// __| |__
// |__|Rb1 Rb6/PGC|__|
// __| |__
// |__|Rb2 Rb5|__|
// __| |__
// |__|Rb3 Rb4|__|
// |____________________|
//
#include <16F88.h>
#device adc=8
//#FUSES XT,NOWDT,PUT,NOPROTECT,BROWNOUT,NOMCLR,NOLVP,NOCPD
//#use fast_io(b) //On ne veut pas barrer le TRIS (port I2C)
#FUSES EC_IO,NOWDT,PUT,NOPROTECT,BROWNOUT,NOMCLR,NOLVP,NOCPD
#FUSES
#use delay(clock=11059200,RESTART_WDT)
#use rs232(baud=9600,parity=N,xmit=PIN_A1,rcv=PIN_A3,bits=8)
//no master clear a5 (reset) ;cpd barrer eedata;nolvp lo-volt prog
/////////////////////////////////////////
void entree_rs232(void); //
void rad(void); //
void aff_stream(int8); //
void ini_pic(void); // P R O T O T Y P E S
int1 a_0,a_1,a_2,a_3,a_4,a_5,a_6,a_7; //
int1 carac_entre; //
int8 carac; //
int8 message; //
/////////////////////////////////////////
//#ZERO_RAM
//#int_RTCC
////////////////////////
#int_RDA //
void RDA_isr(void) //
{ // The (in)famous interrupt that does NOT
carac=getc(); // work!
carac_entre=1; //
} //
////////////////////////
///////////////////////////////////////////////////////////
void ini_pic(void) //
{ //
setup_adc_ports(NO_ANALOGS|VSS_VDD); //
setup_adc(ADC_OFF); //
setup_spi(FALSE); //
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1); //
setup_timer_1(T1_DISABLED); //
setup_timer_2(T2_DISABLED,0,1); //
setup_comparator(NC_NC_NC_NC); //
setup_vref(FALSE); //
enable_interrupts(INT_RDA); //
enable_interrupts(GLOBAL); //
setup_oscillator(False); //
port_b_pullups(true); //
output_a(0); //
output_b(0); //
set_tris_a(0b11111001); // gauche=bit7, droite=bit0 //
set_tris_b(0b11111111); // gauche=bit7, droite=bit0 //
} //
///////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
void aff_stream(int8 message) //
{ //
putchar(65); //
delay_us(104); // To add a second stop bit //
//
putchar(66); //
delay_us(104); //
//
putchar(67); //
delay_us(104); //
//
putchar(68); //
delay_us(104); //
//
putchar(69); //
delay_us(104); //
//
//
if(message==0) //
{ //
putchar(48); //
delay_us(104); //
} //
if(message==1) //
{ //
putchar(49); //
delay_us(104); //
} //
} //
///////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
void main() /////
{ /////
/*=-=*//*=-=*//*=-=*//*=-=*//*=-=*//*=-=*//*=-=*//*=-=*//*=-=*/ /////
ini_pic(); /////
/////
a_0=1; // /////
a_1=1; // /////
a_2=1; // /////
a_3=1; // pour éviter l'envoi de chaînes /////
a_4=1; // à la mise en marche. /////
a_5=1; // /////
a_6=1; // /////
a_7=1; // /////
/////
carac_entre=1; /////
/////
putchar(0xFF); // Pour initialiser la ligne RS232 à MARK /////
/////
while(1) // /////
{ // /////
if(input_state(PIN_B0)) // /////
{ // /////
if(a_0==0) // /////
{ // Character stream is sent /////
aff_stream(0); // on LO-HI transition /////
a_0=1; // /////
} // /////
} // /////
else // /////
{ // /////
a_0=0; // /////
delay_ms(100); // /////
} // /////
/////
/////
if(carac_entre) // /////
{ // /////
delay_ms(50); // Make the LED on pin 1 flash /////
output_high(PIN_A2); // on #int_RDA /////
delay_ms(50); // /////
output_low(PIN_A2); // /////
delay_ms(50); // /////
output_high(PIN_A2); // /////
delay_ms(50); // /////
output_low(PIN_A2); // /////
delay_ms(50); // /////
output_high(PIN_A2); // /////
delay_ms(50); // /////
output_low(PIN_A2); // /////
delay_ms(50); // /////
output_high(PIN_A2); // /////
delay_ms(50); // /////
output_low(PIN_A2); // /////
delay_ms(50); // /////
output_high(PIN_A2); // /////
delay_ms(50); // /////
output_low(PIN_A2); // /////
carac_entre=0; // /////
} // /////
} /////
} /////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
|
I checked everything I could see. The crystal is a 11.0592 MHz (9600 * 1152) and I get my data out at a precise frequency (9600 +/- 10 bps) despite my raw way to add a second stop bit! I checked my interrupts (GLOBAL and #int_RDA), I've read the info. about #int_RDA in the manual and tested with both CCS 4.074 and 3.249.
My test circuit does (is supposed to...) flash an LED on pin 1 when an RS232 character is sent to the PIC. I've checked the waveform on pin 2 (RS232 input) and it's okay (idle at MARK (+5V) and levels ok, BTW, it's fed by a MAX232). I also changed the RS232 input pin (along with it's TRIS) w/o any success.
Did anyone ever get that problem ? and how did you solve it ?
Thanks for your attention. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Dec 01, 2008 4:34 pm |
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| Quote: |
#use rs232(baud=9600,parity=N,xmit=PIN_A1,rcv=PIN_A3,bits=8)
#int_RDA
void RDA_isr(void)
{ // The (in)famous interrupt that does NOT work!
carac=getc();
carac_entre=1;
} |
#int_rda only works with the hardware UART. To use #int_rda, change
your #use rs232() statement to use pins B5 and B2 for Tx and Rx.
Also change your hardware connections to use those pins. |
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PICman
Joined: 02 Nov 2007
Posts: 26
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| Posted: Mon Dec 01, 2008 9:38 pm |
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Wow!
Thanks a lot !!!!
I'll try that tomorrow ! That completely make sense !
Again, thanks ! |
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Guest
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| Posted: Tue Dec 02, 2008 7:36 am |
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IT WORKED !
I just tried it and everything's okay !
Thanks PCM Programmer ! |
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