joven
Joined: 30 Jan 2007
Posts: 56
Location: Viana do Castelo - Portugal
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| Help in AD7714 Driver |
 Posted: Fri Feb 23, 2007 11:27 am |
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Hi
I need make the driver for AD7714, for school project.
I have change the driver of AD7705 for control AD7714.
Is the first time i make a driver for SPI.
Driver:
| Code: |
// AD7714.c
//// Driver routines for the AD7714 chip
//Assuming a 4.9152 crystal ocsillator is used between MCLK IN and MCLK OUT
//connection pins to the PIC
#define ADC_DRDY PIN_B1
#define ADC_DO PIN_B2
#define ADC_DI PIN_B3
#define ADC_RESET PIN_B4
#define ADC_CS PIN_B5
#define ADC_CLK PIN_B6
//Operation modes (MD1, MD0 bits in Setup Register)
#define ADC_NORMAL 0x00
#define ADC_SELF 0x20
#define ADC_ZERO_SCALE 0x40
#define ADC_FULL_SCALE 0x60
//Gain settings (G2, G1, G0 bits in Setup Register)
#define ADC_GAIN_1 0x00
#define ADC_GAIN_2 0x04
#define ADC_GAIN_4 0x08
#define ADC_GAIN_8 0x0C
#define ADC_GAIN_16 0x10
#define ADC_GAIN_32 0x14
#define ADC_GAIN_64 0x18
#define ADC_GAIN_128 0x1C
//// burnout corrente
#define ADC_BURNOUT_ON 0x02
#define ADC_BURNOUT_OFF 0x00
//Fsync (FSYNC bit in Setup Register)
#define ADC_FSYNC_RESET 0x01
#define ADC_FSYNC_START 0x00
// Function prototypes
void adc_init();
void setup_adc_device(int mode, int gain, int buffer, int fsync);
void write_adc_byte(BYTE data);
long read_adc_word();
long read_adc_value();
//initialization routine
void adc_init()
{
output_low(ADC_RESET); // Reset all ADC registers to their default state.
delay_ms(10);
output_high(ADC_RESET);
// See Fig. 17 of AD7714 datsheet
output_high(ADC_CLK); // CLK line at high state
output_high(ADC_CS); // CS line at high state
setup_adc_device(ADC_SELF,ADC_GAIN_1,ADC_BURNOUT_ON,ADC_FSYNC_START);
delay_ms(10);
}
//setup the device paramaters
void setup_adc_device(int mode, int gain,int buffer, int fsync)
{
int8 temp1;
write_adc_byte( 0x10 ); //Communications Register set to write of Setup Register
temp1 = mode|gain|buffer|fsync;
write_adc_byte( temp1 ); //Setup Register info here
}
void write_adc_byte(BYTE data)
{
int8 i;
output_low(ADC_CS);
for(i=0; i<8; i++)
{
output_low(ADC_CLK);
delay_us(50);
output_bit(ADC_DI, shift_left(&data,1,0));
output_high(ADC_CLK);
delay_us(50);
}
output_high(ADC_CS);
}
long read_adc_word()
{
int8 i;
long data;
output_low(ADC_CS);
for(i=0; i<24; i++)
{
output_low(ADC_CLK);
delay_us(50);
shift_left(&data,2,input(ADC_DO));
output_high(ADC_CLK);
delay_us(50);
}
output_high(ADC_CS);
return data;
}
// read an adc value from the channel 1
long read_adc_value()
{
long value;
while ( input(ADC_DRDY) ); // Loop until data is ready
write_adc_byte(0x58); //communications register set to read AIN1
value=read_adc_word();
return value;
}
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Exemple:
| Code: |
#include "lcd.c"
#include <ad7714.c>
void main (void)
{
int dig=0;
long value;
TRISD=0b00001000;
TRISB=0b10000111;
lcd_init();
adc_init();
printf(lcd_putc,"\f ola");
delay_ms(2000);
printf(lcd_putc,"\f");
while(1)
{
value=read_adc_value(); // Read AIN1 inputs
delay_ms(500);
printf(lcd_putc,"\f %lu ",value);
}
}
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I have only configuration one channel. When i try read the adc the function stay in loop until data is ready.
Someone can help-me?
Thanks |
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