Francesco Adamo / ADS7828

mbed library to interface a Texas Instruments' ADS7828, 12-bits, 8-channels, I2C interfaced ADC

Dependents:   ADS7828_demo

ADS7828.cpp

Committer:
frada
Date:
2014-12-30
Revision:
2:2ff328d8e4dd
Parent:
1:19b0f0ba4d12
Child:
3:abbfd9c7f30c

File content as of revision 2:2ff328d8e4dd:

/***************************************************************************
    ADS7828.CPP
    Implementation file for library ADS7828     
    The ADS7828 is a 12-bits, 8-channels, I2C-interfaced from Texas Instruments
    
    (c) 2014 - By Francesco Adamo, Italy
*****************************************************************************/

#include "mbed.h"
#include "ADS7828.h"

// Constructor
ADS7828::ADS7828(PinName sda, PinName scl) : _i2c(sda, scl) {
    _i2c.frequency(100000);  /* Default I2C clock frequency = 100 kHz, Normal Mode */
    address = ADS7828_BASE_ADDRESS;
    VFSR = 2.5F;
}

// Constructor overload
ADS7828::ADS7828(PinName sda, PinName scl, int freq) : _i2c(sda, scl) {
    _i2c.frequency(freq);  /* I2C clock frequency = set to input value */
    address = ADS7828_BASE_ADDRESS;
    VFSR = 2.5F;
}

// Constructor overload
ADS7828::ADS7828(PinName sda, PinName scl, int freq, char subAddress) : _i2c(sda, scl) {
    _i2c.frequency(freq);  /* I2C clock frequency = set to input value */
    address = ADS7828_BASE_ADDRESS | subAddress;
    VFSR = 2.5F;
}


// Constructor overload
ADS7828::ADS7828(PinName sda, PinName scl, int freq, char subAddress, double VREF) : _i2c(sda, scl) {
    _i2c.frequency(freq);  /* I2C clock frequency = set to input value */
    address = ADS7828_BASE_ADDRESS | subAddress;
    VFSR = VREF;
}

// Read a raw value from a given channel
int ADS7828::readRawValue(char mode, char channel) {
    char command, D[2], ack;
    
    command = mode | channel;
    ack = _i2c.write(address, &command, 1);
    if (ack)
        return -1;
        
    ack = _i2c.read(address + 1, D, 2); // Read conversion result
    if (ack)
        return -1;
    else
        return D[0] << 8 | D[1];
}

// Read a raw value from a given channel
double ADS7828::readAnalogValue(char mode, char channel) {
    char command, D[2], ack;
    
    command = mode | channel;
    ack = _i2c.write(address, &command, 1);
    if (ack)
        return -1;
        
    ack = _i2c.read(address + 1, D, 2); // Read conversion result
    if (ack)
        return -1;
    else
        return VFSR/4096*(D[0] << 8 | D[1]);
}