Francesco Adamo / ADS7828

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

Dependents:   ADS7828_demo

ADS7828.cpp@2:2ff328d8e4dd, 2014-12-30 (annotated)

Committer:
frada
Date:
Tue Dec 30 14:41:54 2014 +0000
Revision:
2:2ff328d8e4dd
Parent:
1:19b0f0ba4d12
Child:
3:abbfd9c7f30c
-

Who changed what in which revision?

UserRevisionLine numberNew contents of line
frada 1:19b0f0ba4d12 1 /***************************************************************************
frada 1:19b0f0ba4d12 2 ADS7828.CPP
frada 1:19b0f0ba4d12 3 Implementation file for library ADS7828
frada 1:19b0f0ba4d12 4 The ADS7828 is a 12-bits, 8-channels, I2C-interfaced from Texas Instruments
frada 1:19b0f0ba4d12 5
frada 1:19b0f0ba4d12 6 (c) 2014 - By Francesco Adamo, Italy
frada 1:19b0f0ba4d12 7 *****************************************************************************/
frada 1:19b0f0ba4d12 8
frada 1:19b0f0ba4d12 9 #include "mbed.h"
frada 2:2ff328d8e4dd 10 #include "ADS7828.h"
frada 1:19b0f0ba4d12 11
frada 2:2ff328d8e4dd 12 // Constructor
frada 1:19b0f0ba4d12 13 ADS7828::ADS7828(PinName sda, PinName scl) : _i2c(sda, scl) {
frada 1:19b0f0ba4d12 14 _i2c.frequency(100000); /* Default I2C clock frequency = 100 kHz, Normal Mode */
frada 1:19b0f0ba4d12 15 address = ADS7828_BASE_ADDRESS;
frada 2:2ff328d8e4dd 16 VFSR = 2.5F;
frada 1:19b0f0ba4d12 17 }
frada 1:19b0f0ba4d12 18
frada 2:2ff328d8e4dd 19 // Constructor overload
frada 2:2ff328d8e4dd 20 ADS7828::ADS7828(PinName sda, PinName scl, int freq) : _i2c(sda, scl) {
frada 2:2ff328d8e4dd 21 _i2c.frequency(freq); /* I2C clock frequency = set to input value */
frada 2:2ff328d8e4dd 22 address = ADS7828_BASE_ADDRESS;
frada 2:2ff328d8e4dd 23 VFSR = 2.5F;
frada 2:2ff328d8e4dd 24 }
frada 2:2ff328d8e4dd 25
frada 2:2ff328d8e4dd 26 // Constructor overload
frada 1:19b0f0ba4d12 27 ADS7828::ADS7828(PinName sda, PinName scl, int freq, char subAddress) : _i2c(sda, scl) {
frada 1:19b0f0ba4d12 28 _i2c.frequency(freq); /* I2C clock frequency = set to input value */
frada 1:19b0f0ba4d12 29 address = ADS7828_BASE_ADDRESS | subAddress;
frada 2:2ff328d8e4dd 30 VFSR = 2.5F;
frada 1:19b0f0ba4d12 31 }
frada 1:19b0f0ba4d12 32
frada 1:19b0f0ba4d12 33
frada 2:2ff328d8e4dd 34 // Constructor overload
frada 2:2ff328d8e4dd 35 ADS7828::ADS7828(PinName sda, PinName scl, int freq, char subAddress, double VREF) : _i2c(sda, scl) {
frada 2:2ff328d8e4dd 36 _i2c.frequency(freq); /* I2C clock frequency = set to input value */
frada 2:2ff328d8e4dd 37 address = ADS7828_BASE_ADDRESS | subAddress;
frada 2:2ff328d8e4dd 38 VFSR = VREF;
frada 2:2ff328d8e4dd 39 }
frada 2:2ff328d8e4dd 40
frada 2:2ff328d8e4dd 41 // Read a raw value from a given channel
frada 1:19b0f0ba4d12 42 int ADS7828::readRawValue(char mode, char channel) {
frada 1:19b0f0ba4d12 43 char command, D[2], ack;
frada 1:19b0f0ba4d12 44
frada 1:19b0f0ba4d12 45 command = mode | channel;
frada 1:19b0f0ba4d12 46 ack = _i2c.write(address, &command, 1);
frada 1:19b0f0ba4d12 47 if (ack)
frada 1:19b0f0ba4d12 48 return -1;
frada 1:19b0f0ba4d12 49
frada 1:19b0f0ba4d12 50 ack = _i2c.read(address + 1, D, 2); // Read conversion result
frada 1:19b0f0ba4d12 51 if (ack)
frada 1:19b0f0ba4d12 52 return -1;
frada 1:19b0f0ba4d12 53 else
frada 1:19b0f0ba4d12 54 return D[0] << 8 | D[1];
frada 1:19b0f0ba4d12 55 }
frada 1:19b0f0ba4d12 56
frada 2:2ff328d8e4dd 57 // Read a raw value from a given channel
frada 1:19b0f0ba4d12 58 double ADS7828::readAnalogValue(char mode, char channel) {
frada 1:19b0f0ba4d12 59 char command, D[2], ack;
frada 1:19b0f0ba4d12 60
frada 1:19b0f0ba4d12 61 command = mode | channel;
frada 1:19b0f0ba4d12 62 ack = _i2c.write(address, &command, 1);
frada 1:19b0f0ba4d12 63 if (ack)
frada 1:19b0f0ba4d12 64 return -1;
frada 1:19b0f0ba4d12 65
frada 1:19b0f0ba4d12 66 ack = _i2c.read(address + 1, D, 2); // Read conversion result
frada 1:19b0f0ba4d12 67 if (ack)
frada 1:19b0f0ba4d12 68 return -1;
frada 1:19b0f0ba4d12 69 else
frada 1:19b0f0ba4d12 70 return VFSR/4096*(D[0] << 8 | D[1]);
frada 1:19b0f0ba4d12 71 }