ADC for 12F675

[Joan]

I had found this code on a previous message but doesn't works, why?

#device PIC12F675
#device ADC=10

//////// Fuses: LP,XT,INTRC,HS,NOWDT,WDT,CPD,NOCPD,PROTECT,NOPROTECT,NOMCLR
//////// Fuses: MCLR,PUT,NOPUT,RC,EC,RC_IO,INTRC_IO,BROWNOUT,NOBROWNOUT
#use delay(clock=4000000)

#define PIN_A0 40
#define PIN_A1 41
#define PIN_A2 42
#define PIN_A3 43
#define PIN_A4 44
#define PIN_A5 45

////////////////////////////////////////////////////////////////// Useful defines
#define FALSE 0
#define TRUE 1

////////////////////////////////////////////////////////////////// ADC
// ADC Functions: SETUP_ADC(), SETUP_ADC_PORTS() (aka SETUP_PORT_A),
// SET_ADC_CHANNEL(), READ_ADC()
// Constants used in SETUP_ADC_PORTS() are: (These may be ORed together)

#define NO_ANALOGS 0
#define ALL_ANALOG 15 //| GP0 GP1 GP2 GP4
#define AN0_ANALOG 1 //| GP0
#define AN1_ANALOG 2 //| GP1
#define AN2_ANALOG 4 //| GP2
#define AN3_ANALOG 8 //| GP4
//#define VREF 0x4002
#define VSS_VDD 0x0000
#define VSS_VREF 0x4002 //| Range 0-Vref
// 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_16 0x51
#define ADC_CLOCK_DIV_32 0x21
#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

#define RED PIN_A4
#define GREEN PIN_A5

//Value to save ADC reading

long Value;

void ReadMyAdc()
{
Value=read_adc(adc_read_only);
//If more then 50%
if (Value > 512)//Flash Green
{
output_bit(GREEN,1);
output_bit(RED,0);
delay_ms (250);
output_bit(GREEN,0);
output_bit(RED,0);
delay_ms(250);
}
if (Value < 513)//Flash Red
{
output_bit(GREEN,0);
output_bit(RED,1);
delay_ms (250);
output_bit(GREEN,0);
output_bit(RED,0);
delay_ms(250);
}

}


void main()
{

set_tris_a(0xf);//RA0, RA1, RA2, RA3 as Inputs
//RA4, RA5 as Outputs
setup_adc_ports( AN0_ANALOG );
setup_adc(ADC_CLOCK_INTERNAL );
set_adc_channel(0);

while(1)
{
ReadMyAdc();
}
}

[Felix Althaus]

Hello

What do you mean with "it doesn't work"? Does it compile? What exactly doesn't work, what results do you get?

Felix

[Joan]

I don't have any error when compiling.

It must change the blinking LED (GREEN or RED) when Vadc (AN0_Channel) is great or less 2.5V, respectively. But only blinks the GREEN everytime, like ADC where not runnig well. I don't have any idea ...

Regards.

Joan

[Charlie U]

I haven't gone through your entire program, but I did notice that you are using the "read_only" parameter in your read_adc() function. You haven't started the adc anywhere, so the reading you get is the initialization value of the adc result register.

I would suggest leaving out the parameter in the read_adc() function altogether, and letting the compiler do the work. It will start the adc and wait for it to be done and then continue on with your code.

Change:

[future]

I would use the output_toggle() function too.

Optimize more like:

if(Value>512) {
do something;
} else do other thing;

[Joan]

Hello Guys (Charlie U & future & CO.):

I've rewited the code with the lines that you suggestet. Now works fine. Thx very much for your help. Here it is the code for who wants to test:

#device PIC12F675
#device ADC=10

//////////////////////////////////////////////////
//
// Connections:
//
// PIN 1 to VCC
// PIN 2 to 220 Ohms resistor + LED (GREEN)
// PIN 3 to 220 Ohms resistor + LED (RED)
// PIN 4 n.c.
// PIN 5 n.c.
// PIN 6 n.c.
// PIN 7 to 3 pins Potentiomenter 10k Ohms ( PIN1 to VCC, PIN 2 to PIC
// PIN7, PIN 3 to GND)
// PIN 8 to GND
//
////////////////////////////////////////////////////

//////// Fuses: LP,XT,INTRC,HS,NOWDT,WDT,CPD,NOCPD,PROTECT,NOPROTECT,NOMCLR
//////// Fuses: MCLR,PUT,NOPUT,RC,EC,RC_IO,INTRC_IO,BROWNOUT,NOBROWNOUT
#use delay(clock=4000000)

#define PIN_A0 40
#define PIN_A1 41
#define PIN_A2 42
#define PIN_A3 43
#define PIN_A4 44
#define PIN_A5 45

////////////////////////////////////////////////////////////////// Useful defines
#define FALSE 0
#define TRUE 1

////////////////////////////////////////////////////////////////// ADC
// ADC Functions: SETUP_ADC(), SETUP_ADC_PORTS() (aka SETUP_PORT_A),
// SET_ADC_CHANNEL(), READ_ADC()
// Constants used in SETUP_ADC_PORTS() are: (These may be ORed together)

#define NO_ANALOGS 0
#define ALL_ANALOG 15 //| GP0 GP1 GP2 GP4
#define AN0_ANALOG 1 //| GP0
#define AN1_ANALOG 2 //| GP1
#define AN2_ANALOG 4 //| GP2
#define AN3_ANALOG 8 //| GP4
//#define VREF 0x4002
#define VSS_VDD 0x0000
#define VSS_VREF 0x4002 //| Range 0-Vref
// 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_16 0x51
#define ADC_CLOCK_DIV_32 0x21
#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

#define RED PIN_A4
#define GREEN PIN_A5

//Value to save ADC reading


void ReadMyAdc()
{
long Value;
Value=read_adc();
//Value=read_adc(adc_read_only);

//If more then 50%
if (Value > 512)//Flash Green
{
output_bit(GREEN,1);
output_bit(RED,0);
delay_ms (250);
output_bit(GREEN,0);
output_bit(RED,0);
delay_ms(250);
}
else //if (Value < 513) Flash Red
{
output_bit(GREEN,0);
output_bit(RED,1);
delay_ms (250);
output_bit(GREEN,0);
output_bit(RED,0);
delay_ms(250);
}

}


void main()
{

set_tris_a(0xf);//RA0, RA1, RA2, RA3 as Inputs
//RA4, RA5 as Outputs
setup_adc_ports( AN0_ANALOG );
setup_adc(ADC_CLOCK_INTERNAL );
set_adc_channel(0);

while(1)
{
ReadMyAdc();
}
}