Connect PIC16F876A to AD7745

[Diogogp24]

I guys i am inserted in a university project to measure capacitance values using a PIC16F876A and AD7745.
So i never programmed a PIC i really need some help to do the configurations between this 2 components. After that i have 5 variables that are connected to a multiplexer in order to reach different capacitance sensors.
If someone could provideme some help mostly in the configuration would be perfect.
To be serius i have asked help to chapgpt but i dont trust him, but this is the code that he gave me:

#include <xc.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <pic16lf1847.h>

#define _XTAL_FREQ 8000000 // Define your oscillator frequency here

// I2C Configuration
#define I2C_BAUD_RATE 100000 // Desired I2C baud rate (100 kHz)

// AD7745 I2C Address
#define AD7745_ADDRESS 0x48 // The 7-bit I2C address of the AD7745

// Define your pin variables
#define A3_PIN 2
#define A2_PIN 1
#define A1_PIN 18
#define A0_PIN 17
#define EN_PIN 3

// Function to initialize I2C
void I2C_Init() {
SSP1CON1 = 0b00101000; // Configure I2C for Master mode, clock = FOSC / (4 * (SSP1ADD+1))
SSP1CON2 = 0;
SSP1ADD = (_XTAL_FREQ / (4 * I2C_BAUD_RATE)) - 1;
SSP1STAT = 0;
}

// Function to send a start condition on I2C bus
void I2C_Start() {
SSP1CON2bits.SEN = 1;
while (SSP1CON2bits.SEN);
}

// Function to send a stop condition on I2C bus
void I2C_Stop() {
SSP1CON2bits.PEN = 1;
while (SSP1CON2bits.PEN);
}

// Function to transmit a byte on I2C bus
void I2C_Write(uint8_t data) {
SSP1BUF = data;
while (SSP1STATbits.BF);
__delay_us(5); // Add a small delay for safety
}

// Function to receive a byte on I2C bus
uint8_t I2C_Read(bool ack) {
SSP1CON2bits.RCEN = 1;
while (!SSP1STATbits.BF);
uint8_t data = SSP1BUF;
SSP1CON2bits.ACKDT = (ack) ? 0 : 1; // Set the ACK/NACK bit
SSP1CON2bits.ACKEN = 1; // Send ACK/NACK bit
while (SSP1CON2bits.ACKEN);
return data;
}

// Function to configure the AD7745 for capacitance measurement
void AD7745_Configuration() {
// Add your AD7745 configuration code here
// For example, you can set the AD7745 registers for desired settings
}

// Function to measure capacitance with the AD7745
uint32_t AD7745_MeasureCapacitance() {
// Add your code to read capacitance data from the AD7745
// For example, you can read the capacitance registers and convert the data
// into a meaningful format (e.g., microfarads or picofarads)
}

// Function to set the inputs for the AD7745 using the given pin values
void setInputs(int a3, int a2, int a1, int a0, int en) {
// Add code to set the input pins (A3_PIN, A2_PIN, A1_PIN, A0_PIN, EN_PIN) here
// For example, you can use appropriate port manipulation instructions
// to set the pins to the desired values
}

// Function to measure capacitance for a specific electrode
void measureCapacitance(int electrode) {
// Set the output pins based on the selected case number
switch (electrode) {
case 1:
setInputs(0, 0, 0, 0, 1);
break;
case 2:
setInputs(0, 0, 0, 1, 1);
break;
case 3:
setInputs(0, 0, 1, 0, 1);
break;
case 4:
setInputs(0, 0, 1, 1, 1);
break;
case 5:
setInputs(0, 1, 0, 0, 1);
break;
case 6:
setInputs(0, 1, 0, 1, 1);
break;
case 7:
setInputs(0, 1, 1, 0, 1);
break;
case 8:
setInputs(0, 1, 1, 1, 1);
break;
case 9:
setInputs(1, 0, 0, 0, 1);
break;
case 10:
setInputs(1, 0, 0, 1, 1);
break;
case 11:
setInputs(1, 0, 1, 0, 1);
break;
case 12:
setInputs(1, 0, 1, 1, 1);
break;
case 13:
setInputs(1, 1, 0, 0, 1);
break;
case 14:
setInputs(1, 1, 0, 1, 1);
break;
default:
// Invalid electrode number
break;
}

int numIterations = 200;
int interval = 50; // Delay between measurements in milliseconds

for (int i = 0; i < numIterations; i++) {
// Perform capacitance measurement for the given electrode
uint32_t capacitance = AD7745_MeasureCapacitance();
double capacity = (((double) capacitance - 8388608.0) / 8388608.0) * 4.095999;

// Print the capacitance value
printf("Electrode: %d, Capacitance: %.4f pF\n", electrode, capacity);

// Delay between measurements
__delay_ms(interval);
}
}

void main(void) {
// Initialize the I2C communication
I2C_Init();

// Check communication with AD7745 by reading the device ID register
I2C_Start(); // Send Start condition
I2C_Write(AD7745_ADDRESS << 1); // Send AD7745 address with Write bit (0)
I2C_Write(0x0C); // Send the address of the Device ID register
I2C_Start(); // Send repeated start condition
I2C_Write((AD7745_ADDRESS << 1) | 0x01); // Send AD7745 address with Read bit (1)

uint8_t deviceId = I2C_Read(0); // Read the Device ID register, acknowledge with ACK

I2C_Stop(); // Send Stop condition

if (deviceId == 0x09) {
printf("AD7745 Communication Successful! Device ID: 0x%02X\n", deviceId);
} else {
printf("AD7745 Communication Failed. Device ID: 0x%02X\n", deviceId);
while (1); // End the program if communication fails
}

// Configure the AD7745 for capacitance measurement
AD7745_Configuration();

// Wait for stabilization before taking measurements
__delay_ms(100);

int choice;

// Prompt the user for electrode analysis choice
printf("Select an option:\n");
printf("1. Analyze all electrodes sequentially\n");
printf("2. Choose a specific electrode\n");
printf("Enter your choice: ");
scanf("%d", &choice);

if (choice == 1) {
// Analyze all electrodes sequentially
for (int electrode = 1; electrode <= 14; electrode++) {
measureCapacitance(electrode);
}
} else if (choice == 2) {
// Choose a specific electrode
int selectedElectrode;
printf("Enter the electrode number (1-14): ");
scanf("%d", &selectedElectrode);

// Check if the electrode number is within the valid range
if (selectedElectrode >= 1 && selectedElectrode <= 14) {
measureCapacitance(selectedElectrode);
} else {
printf("Invalid electrode number!\n");
}
} else {
printf("Invalid choice!\n");
}

while (1) {
// Main program loop
// Add your other code here
}
}

[dyeatman]

Wrong compiler. This site is for CCS C

You need to go to the Microchip XC compiler forum here:
https://forum.microchip.com/s/?&page=1&offset=0&filters=false&selectedlist=section1&followingtopics=false&myforums=false&myactivity=false
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[Diogogp24]

[temtronic]

it'd be interesting to tell chapgpt to USE the CCS compiler and see what it comes up with !

[Diogogp24]

[dyeatman]

Interesting. As expected it doesn't compile, a number of errors, but looks half way promising.
It uses, for example <include i2C.c> rather than #use I2C
It doesn't know #use rs232...
It throws in some (Same as previous code) rather than the actual code which is unusual.
I made few tweaks and got it to compile...still a bit more needed though.
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