Problems with 16F88 and int_rda

[Gabriel Caffese]

Hi everyone,

Previous data, before telling wich is the problem.

I�m using CCS 3.187
The example EX_STISR.C works ok with 16F88 (it buffers up outgoing serial data). Outgoing data is sent OK, and incoming data is received OK.

The only problem with this example, is that it does not use INT_RDA.

The program I compiled, works OK a 16F628, and it does this:

Waits until INT_RBO is activated, and sends the character "?".
Then waits 200ms, and hopes to receive ANY character.
If it receives one, then blinks an led 3 times.

Well, first time you activate INT_RB0, it works fine, but NEVER AGAIN.
Is there anything wrong in my code, that I can not see ???
I think it�s OK
Well, hope someone could help me.

Here goes the code:

#include <16F88.H>
#device *=16
#fuses XT,NOWDT,NOBROWNOUT,NOPROTECT,PUT,NOLVP,MCLR,NODEBUG
#use delay(clock=7327280)
#use rs232(baud=38400, xmit=PIN_B5,rcv=PIN_B2, ERRORS)

static char Rx[10];
static boolean rda;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////// DEFINO FUNCIONES //////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

// Encendido intermitente del led //
void blink_green(int veces, int duracion)
{ int i;
for (i=0;i<veces;i++)
{
output_bit(PIN_A3,1);
delay_ms(duracion);
output_bit(PIN_A3,0);
delay_ms(duracion);
}
}

// Encendido intermitente del led //
void blink_red(int veces, int duracion)
{ int i;
for (i=0;i<veces;i++)
{
output_bit(PIN_A2,1);
delay_ms(duracion);
output_bit(PIN_A2,0);
delay_ms(duracion);
}
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////// RUTINAS DE INTERRUPCION ///////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

#int_ext
void ext_isr()
{
}

#int_rda
void serial_isr()
{
rda=TRUE;
Rx[0]=getc();
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////// ///////////////////////////////////////////////////
///////////////////////////////////////////////// PROGRAMA PRINCIPAL ///////////////////////////////////////////////////
///////////////////////////////////////////////// ///////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void main()
{

#ZERO_RAM

// Configuro perif�ricos para bajo consumo //
setup_timer_2(T2_DISABLED,0,2);
setup_ccp1(CCP_OFF);
setup_adc(ADC_OFF);
setup_vref(FALSE);

// Configuro puertos para bajo consumo //
port_b_pullups(TRUE);

// Habilito interrupciones //
ext_int_edge(H_to_L);
enable_interrupts(INT_EXT);
enable_interrupts(INT_RDA);
enable_interrupts(GLOBAL);

// Fin de configuraci�n //
blink_red(3,50);
blink_green(3,50);

// Habilito RS232 //
output_bit(PIN_A1,0);
output_bit(PIN_A0,1);

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////// RUTINA QUE DETERMINA LA TAREA QUE DEBE REALIZARSE ////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

Loop:
sleep();

///////////////////////////////////////////////////////////
if (input(PIN_B0) == FALSE)
{
do {} While (input(PIN_B0) == FALSE);
delay_ms(200);
putc('?');
delay_ms(200);
}

if (rda==TRUE) blink_green(3,10);
rda = FALSE;
///////////////////////////////////////////////////////////

goto Loop;
}

[Ttelmah]

[Gabriel Caffese]

Ttelmah,

First, thanks for replying.

The process is this way. INT_RB0 (int.ext.) and INT_RDA are enabled.
When an external interrupt is generated, the PIC gets out of sleep mode, then the UART sends a character, to which the PC has to reply to (it certainly does so).
The thing is that first time the PIC receives an external interrupt, everything works fine. But next time you generate an external interrupt, the character is sent to the PC (and the PC replies with another), but 16F88 doesn't seem to detect it, cause the led doesn?t blink at all.

Any clue ?

Gabriel.-

[Joan]

[Humberto]

Hi Gabriel,

I will try in this way.

[Joan]

Hi:
If you have a look at the 16F88/87 Datasheet it says something like ...

[Gabriel Caffese]

Humberto y Joan,

Gracias a ambos por responder. Sigo en ingl�s, para que el resto entienda.
The RB0 ISR, automatically clears that flags when exiting.
Now, I have found the problem -but don�t know how to solve it-

For lowering power consumption to 4uA, I have to turn off every peripheral. RS232 transmision is being done using pairs of IR Led and phototransistor on both sides.
So, I stop "feeding" both IR, and am on 100uA, then, disabling RS232 on 16F88, get those 4uA. The only thing that keeps working (and consuming) is T1, with an 32,768Khz crystal.
Then, when receiving an external interrupt, I turn on RS232 module. TX works OK, but RX does NEVER work again.
It works OK before turning off RS232, but if I disable it, and then re-enable, it will never ever work until reset.

Up to now, have no clues. Any help ??

Gabriel.-

[Ttelmah]

[Gabriel Caffese]

Ttelmah,

I�m going out to work. I will check this tonight and
post what happened. Thank�s for this information.

Gabriel.-