A/D and PIC16F676 does not work

[Richi]

Hi all,

after 10 or 15 hours troubleshooting, testing and 5 killed PICs, I�m at the end.
Why does the ADC of the 16F676 not work? The code is perfect running at the 16F877.
All other functions are working at the 16F676.When I give a fixed number for the ADC value- the LED�s are working.

Is it a bug in the CCS-compiler?
Here is the code:


#if defined(_PCM_)
#endif
#include <16F676.h>
#device adc=10
#fuses intrc_io,NOWDT,PROTECT,NOBROWNOUT,PUT,MCLR,CPD

#use delay (clock=4000000)
#use standard_io(A)
#use standard_io(C)

//#ROM 0x3ff = {0x3480} // set osccal


// Pins


#define TAN PIN_A5
#define TSCHARF PIN_A2
#define LED1 PIN_C5
#define LED2 PIN_C4
#define LED3 PIN_C3
#define LEDAN PIN_C1
#define LEDSCHARF PIN_C2

int1 ADLESEN = 0;
int1 Blinkerled4 = 0;

int1 tansetzen = 0;
int1 ledscharfspeicher = 0;
int1 schalteran = 0;
int1 zustandalt = 0;
int1 zustandneu = 0;

int16 izeit2s = 0;
int8 iSmoothing = 0;
int8 iLedzaehler = 0;
int8 iTimertakt = 0;
int8 ieinzaehler = 1;

int16 ianalogwert1 = 1023;
int16 iwert_1 = 0;

int16 igrenzeled1 = 1023;
int16 igrenzeled1_2 = 392;
int16 igrenzeled2_3 = 381;
int16 igrenzeled3_4 = 368;

int16 ianalogwertalt1 = 0;

#int_timer1
void timer1_isr()
{

ADLESEN = 1;

set_timer1(15536); // (100ms)

++iLEDZAEHLER;


if ((input(TSCHARF)) && (izeit2s <= 9) )
{
++izeit2s;
}

if (izeit2s == 10)
{
output_HIGH(LEDSCHARF);
ledscharfspeicher = 1;
}
else
{
output_LOW(LEDSCHARF);
ledscharfspeicher = 0;
}

if (!input(TSCHARF) )
{
izeit2s = 0;
}

}


#INT_EXT
void ext_isr()
{
set_timer1(15536);
izeit2s = 0;
}


main()
{


setup_comparator(NC_NC_NC_NC);
setup_adc( ADC_CLOCK_INTERNAL );
setup_adc_ports( sAN3 | VSS_VDD);
setup_timer_1 ( T1_INTERNAL | T1_DIV_BY_2 );

enable_interrupts(GLOBAL);
enable_interrupts(INT_TIMER1);
enable_interrupts(INT_EXT);

ext_int_edge(L_TO_H);

ianalogwertalt1 = 0;
ianalogwert1 = 1023;
ADLESEN = 1;
iLEDZAEHLER = 0;
schalteran = 1;


for(;;)
{

output_LOW(PIN_A0);
output_LOW(PIN_A1);
output_LOW(PIN_C0);

igrenzeled1 = 1023;
igrenzeled1_2 = 430;
igrenzeled2_3 = 410;
igrenzeled3_4 = 368;


//Analog/Digitalwandlung

set_adc_channel(sAN3);
delay_us(10);
iwert_1 = read_adc();

{
ianalogwert1 = (iwert_1);




tansetzen = 0;

zustandneu = input(TAN);

if ((zustandneu == 1) && (zustandalt == 0))
{
tansetzen = 1;
}

zustandalt = zustandneu;


if (( tansetzen == 1) && (ledscharfspeicher == 1 ))
{
schalteran = 1;
}
else schalteran = 0;





if ( schalteran == 1 )
{
++ieinzaehler;
}

if ( ieinzaehler == 1 )
{
output_HIGH(LEDAN);
}

if ( ieinzaehler == 2 )
{
output_LOW(LEDAN), output_LOW(LED1), output_LOW(LED2), output_LOW(LED3);
}





if ( ((ieinzaehler == 0) && (!input(TSCHARF))) || ((ieinzaehler == 2) && (input(TSCHARF))) )
{
ieinzaehler = 0, output_LOW(LEDSCHARF), sleep();
}





if ( iLEDZAEHLER == 3)
{
blinkerled4 = 1;
}
if ( iLEDZAEHLER >= 4)
{
blinkerled4 = 0;
iLEDZAEHLER = 0;
}



if ( ieinzaehler == 1 )
{

if ( (ianalogwert1<=igrenzeled1 && ianalogwert1>=igrenzeled1_2) )
{
output_HIGH(LED1);
}
else
{
output_LOW(LED1);
}

if ( (ianalogwert1<igrenzeled1_2 && ianalogwert1>=igrenzeled2_3) )
{
output_HIGH(LED2);
}
else
{
output_LOW(LED2);
}

if ( (ianalogwert1<igrenzeled3_4 && blinkerled4 == 1 && ianalogwert1>=20) || (ianalogwert1<igrenzeled2_3 && ianalogwert1>=igrenzeled3_4) )
{
output_HIGH(LED3);
}
else
{
output_LOW(LED3);
}

}



}
}

[PCM programmer]

This line is not correct:

[Richi]

Thank you very much, but it also doesn�t work. Something changed: The value now was read from ADC I think is now 1024 - the first LED is lighting, before it must have been 0 cause no lights were burning. Im not sure - my ICD2 module also doesn�t work with this (f...) device...
The reason for using sAN3 was: I took the parameters from the CCS header file:

setup_adc_ports(sAN3 | VSS_VDD ); -- is that o.k.? But also no change when writing (3 | VSS_VDD )!

////////////////////////////////////////////////////////////////// ADC
// ADC Functions: SETUP_ADC(), SETUP_ADC_PORTS() (aka SETUP_PORT_A),
// SET_ADC_CHANNEL(), READ_ADC()
// Constants used in SETUP_ADC_PORTS() are:
// or together any combination
// of the sANx constants with one
// of the others.
#define sAN0 1 //| A0
#define sAN1 2 //| A1
#define sAN2 4 //| A2
#define sAN3 8 //| A4
#define sAN4 16 //| C0
#define sAN5 32 //| C1
#define sAN6 64 //| C2
#define sAN7 128 //| C3
#define NO_ANALOGS 0 // None
// The following may be OR'ed in with the above using |
#define VSS_VDD 0x8000 // Range 0-Vdd
#define VREF_VREF 0x9000 // Range VrefL-VrefH
#define VRL_VRH 0xA000 // Range Vrl-Vrh
#define VSS_VREF 0xB000 // Range 0-VrefH
#define VSS_VRH 0xC000 // Range 0-Vrl
#define VREF_VDD 0xD000 // Range VrefL-Vdd
#define VRL_VDD 0xE000 // Range Vrl-Vdd
#define VSS_VRL 0xF000 // Range 0-Vrl
// Constants used for SETUP_ADC() are:
#define ADC_OFF 0 // ADC Off
#define ADC_CLOCK_DIV_2 1
#define ADC_CLOCK_DIV_4 0x41
#define ADC_CLOCK_DIV_8 0x11
#define ADC_CLOCK_DIV_32 0x21
#define ADC_CLOCK_DIV_16 0x51
#define ADC_CLOCK_DIV_64 0x61
#define ADC_CLOCK_INTERNAL 0x31 // Internal 2-6us

// Constants used in READ_ADC() are:
#define ADC_START_AND_READ 7 // This is the default if nothing is specified
#define ADC_START_ONLY 1
#define ADC_READ_ONLY 6

[PCM programmer]

[Mark]

5 killed PICs and now the ICD. Can't blame the compiler for all that. You must have problems without your hardware.

[Richi]

No Problem with hardware... the pics where killed cause of soldering/desoldering. My ICD is o.k. but doesn�t work with THIS device.

Compilerversion is 3.180

Thanks for help...

[PCM programmer]

I compiled the following program with PCM vs. 3.180 and looked at
the .LST file. I think it should work OK.

Also note that A/D channel 3 is on pin RA4, which is pin 3 on the chip.
Make sure your A/D signal is going to pin 3 on the PIC.

Try the following program and see if it works. Display the results using
printf. Make sure you use "%LX" to display a 16-bit result with printf.