Arve Seljebu
A library for ADS1015 and ADS1115 from Texas Instruments.
Dependents: IGGE_Power ADS1015-hello_world ADS1115-hello_world frdm_rtos_Eth ... more
Use like this
#include "mbed.h"
#include "Adafruit_ADS1015.h"
#include "USBSerial.h"
#define SERIAL_BAUD_RATE 9600
I2C i2c(p23, p18);
Adafruit_ADS1015 ads(&i2c);
USBSerial pc; // USB CDC serial port
int main() {
uint16_t reading;
while (1) {
reading = ads.readADC_SingleEnded(0); // read channel 0
pc.printf("reading: %d\r\n", reading); // print reading
wait(2); // loop 2 sek
}
}
Library ported from Arduino at github repository.
Breakout boards from Adafruit: http://learn.adafruit.com/adafruit-4-channel-adc-breakouts/overview
GitHub repository: https://github.com/adafruit/Adafruit_ADS1X15
Adafruit_ADS1015.cpp
- Committer:
- arve0
- Date:
- 2014-10-11
- Revision:
- 5:aa277517f0ad
- Parent:
- 4:6445a678d458
File content as of revision 5:aa277517f0ad:
/**************************************************************************/
/*!
@file Adafruit_ADS1015.cpp
@author K.Townsend (Adafruit Industries)
@license BSD (see LICENSE.txt)
Ported to mbed by Arve Seljebu - arve0.github.io
Driver for the ADS1015/ADS1115 ADC
This is a library for the Adafruit MPL115A2 breakout
----> https://www.adafruit.com/products/1083
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
@section HISTORY
v1.0 - First release
v1.1.1 - Ported to mbed
*/
/**************************************************************************/
#include <mbed.h>
#include "Adafruit_ADS1015.h"
/**************************************************************************/
/*!
@brief Writes 16-bits to the specified destination register
*/
/**************************************************************************/
void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value)
{
char cmd[3];
cmd[0] = (char)reg;
cmd[1] = (char)(value>>8);
cmd[2] = (char)(value & 0xFF);
m_i2c->write(i2cAddress, cmd, 3);
}
/**************************************************************************/
/*!
@brief Reads 16-bits from the specified register
*/
/**************************************************************************/
uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg)
{
char data[2];
data[0] = reg; // temporary use this to send address to conversion register
m_i2c->write(i2cAddress, data, 1);
m_i2c->read(i2cAddress, data, 2);
return (data[0] << 8 | data [1]);
}
/**************************************************************************/
/*!
@brief Instantiates a new ADS1015 class w/appropriate properties
*/
/**************************************************************************/
Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress)
{
// shift 7 bit address 1 left: read expects 8 bit address, see I2C.h
m_i2cAddress = i2cAddress << 1;
m_conversionDelay = ADS1015_CONVERSIONDELAY;
m_bitShift = 4;
m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
m_i2c = i2c;
}
/**************************************************************************/
/*!
@brief Instantiates a new ADS1115 class w/appropriate properties
*/
/**************************************************************************/
Adafruit_ADS1115::Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress)
{
// shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h
m_i2cAddress = i2cAddress << 1;
m_conversionDelay = ADS1115_CONVERSIONDELAY;
m_bitShift = 0;
m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
m_i2c = i2c;
}
/**************************************************************************/
/*!
@brief Sets the gain and input voltage range
*/
/**************************************************************************/
void Adafruit_ADS1015::setGain(adsGain_t gain)
{
m_gain = gain;
}
/**************************************************************************/
/*!
@brief Gets a gain and input voltage range
*/
/**************************************************************************/
adsGain_t Adafruit_ADS1015::getGain()
{
return m_gain;
}
/**************************************************************************/
/*!
@brief Gets a single-ended ADC reading from the specified channel
*/
/**************************************************************************/
uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel)
{
if (channel > 3) {
return 0;
}
// Start with default values
uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
// Set PGA/voltage range
config |= m_gain;
// Set single-ended input channel
switch (channel) {
case (0):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
break;
case (1):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
break;
case (2):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
break;
case (3):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
break;
}
// Set 'start single-conversion' bit
config |= ADS1015_REG_CONFIG_OS_SINGLE;
// Write config register to the ADC
writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
// Wait for the conversion to complete
wait_ms(m_conversionDelay);
// Read the conversion results
// Shift 12-bit results right 4 bits for the ADS1015
return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
}
/**************************************************************************/
/*!
@brief Reads the conversion results, measuring the voltage
difference between the P (AIN0) and N (AIN1) input. Generates
a signed value since the difference can be either
positive or negative.
*/
/**************************************************************************/
int16_t Adafruit_ADS1015::readADC_Differential_0_1()
{
// Start with default values
uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
// Set PGA/voltage range
config |= m_gain;
// Set channels
config |= ADS1015_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N
// Set 'start single-conversion' bit
config |= ADS1015_REG_CONFIG_OS_SINGLE;
// Write config register to the ADC
writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
// Wait for the conversion to complete
wait_ms(m_conversionDelay);
// Read the conversion results
uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
if (m_bitShift == 0) {
return (int16_t)res;
} else {
// Shift 12-bit results right 4 bits for the ADS1015,
// making sure we keep the sign bit intact
if (res > 0x07FF) {
// negative number - extend the sign to 16th bit
res |= 0xF000;
}
return (int16_t)res;
}
}
/**************************************************************************/
/*!
@brief Reads the conversion results, measuring the voltage
difference between the P (AIN2) and N (AIN3) input. Generates
a signed value since the difference can be either
positive or negative.
*/
/**************************************************************************/
int16_t Adafruit_ADS1015::readADC_Differential_2_3()
{
// Start with default values
uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
// Set PGA/voltage range
config |= m_gain;
// Set channels
config |= ADS1015_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N
// Set 'start single-conversion' bit
config |= ADS1015_REG_CONFIG_OS_SINGLE;
// Write config register to the ADC
writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
// Wait for the conversion to complete
wait_ms(m_conversionDelay);
// Read the conversion results
uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
if (m_bitShift == 0) {
return (int16_t)res;
} else {
// Shift 12-bit results right 4 bits for the ADS1015,
// making sure we keep the sign bit intact
if (res > 0x07FF) {
// negative number - extend the sign to 16th bit
res |= 0xF000;
}
return (int16_t)res;
}
}
/**************************************************************************/
/*!
@brief Sets up the comparator to operate in basic mode, causing the
ALERT/RDY pin to assert (go from high to low) when the ADC
value exceeds the specified threshold.
This will also set the ADC in continuous conversion mode.
*/
/**************************************************************************/
void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold)
{
// Start with default values
uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match
ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode
ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode
ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode
// Set PGA/voltage range
config |= m_gain;
// Set single-ended input channel
switch (channel) {
case (0):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
break;
case (1):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
break;
case (2):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
break;
case (3):
config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
break;
}
// Set the high threshold register
// Shift 12-bit results left 4 bits for the ADS1015
writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift);
// Write config register to the ADC
writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
}
/**************************************************************************/
/*!
@brief In order to clear the comparator, we need to read the
conversion results. This function reads the last conversion
results without changing the config value.
*/
/**************************************************************************/
int16_t Adafruit_ADS1015::getLastConversionResults()
{
// Wait for the conversion to complete
wait_ms(m_conversionDelay);
// Read the conversion results
uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
if (m_bitShift == 0) {
return (int16_t)res;
} else {
// Shift 12-bit results right 4 bits for the ADS1015,
// making sure we keep the sign bit intact
if (res > 0x07FF) {
// negative number - extend the sign to 16th bit
res |= 0xF000;
}
return (int16_t)res;
}
}
Analog Devices ADS1015
16-Bit Analog-to-Digital Converter ADS1115