Arve Seljebu / ADS1015

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@0:8174d9ceeca1, 2013-11-10 (annotated)

Committer:
arve0
Date:
Sun Nov 10 18:22:27 2013 +0000
Revision:
0:8174d9ceeca1
Child:
2:d864e21d4e58
Child:
3:fb735fb343de
Ported from Adafruit's arduino library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
arve0 0:8174d9ceeca1 1 /**************************************************************************/
arve0 0:8174d9ceeca1 2 /*!
arve0 0:8174d9ceeca1 3 @file Adafruit_ADS1015.cpp
arve0 0:8174d9ceeca1 4 @author K.Townsend (Adafruit Industries)
arve0 0:8174d9ceeca1 5 @license BSD (see LICENSE.txt)
arve0 0:8174d9ceeca1 6
arve0 0:8174d9ceeca1 7 Ported to mbed by Arve Seljebu - arve0.github.io
arve0 0:8174d9ceeca1 8
arve0 0:8174d9ceeca1 9 Driver for the ADS1015/ADS1115 ADC
arve0 0:8174d9ceeca1 10
arve0 0:8174d9ceeca1 11 This is a library for the Adafruit MPL115A2 breakout
arve0 0:8174d9ceeca1 12 ----> https://www.adafruit.com/products/1083
arve0 0:8174d9ceeca1 13
arve0 0:8174d9ceeca1 14 Adafruit invests time and resources providing this open source code,
arve0 0:8174d9ceeca1 15 please support Adafruit and open-source hardware by purchasing
arve0 0:8174d9ceeca1 16 products from Adafruit!
arve0 0:8174d9ceeca1 17
arve0 0:8174d9ceeca1 18 @section HISTORY
arve0 0:8174d9ceeca1 19
arve0 0:8174d9ceeca1 20 v1.0 - First release
arve0 0:8174d9ceeca1 21 v1.1.1 - Ported to mbed
arve0 0:8174d9ceeca1 22 */
arve0 0:8174d9ceeca1 23 /**************************************************************************/
arve0 0:8174d9ceeca1 24
arve0 0:8174d9ceeca1 25 #include <mbed.h>
arve0 0:8174d9ceeca1 26 #include "Adafruit_ADS1015.h"
arve0 0:8174d9ceeca1 27
arve0 0:8174d9ceeca1 28 /**************************************************************************/
arve0 0:8174d9ceeca1 29 /*!
arve0 0:8174d9ceeca1 30 @brief Writes 16-bits to the specified destination register
arve0 0:8174d9ceeca1 31 */
arve0 0:8174d9ceeca1 32 /**************************************************************************/
arve0 0:8174d9ceeca1 33 void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value) {
arve0 0:8174d9ceeca1 34 char cmd[3];
arve0 0:8174d9ceeca1 35 cmd[0] = (char)reg;
arve0 0:8174d9ceeca1 36 cmd[1] = (char)(value>>8);
arve0 0:8174d9ceeca1 37 cmd[2] = (char)(value & 0xFF);
arve0 0:8174d9ceeca1 38 m_i2c->write(i2cAddress, cmd, 3);
arve0 0:8174d9ceeca1 39 }
arve0 0:8174d9ceeca1 40
arve0 0:8174d9ceeca1 41 /**************************************************************************/
arve0 0:8174d9ceeca1 42 /*!
arve0 0:8174d9ceeca1 43 @brief Reads 16-bits from the specified register
arve0 0:8174d9ceeca1 44 */
arve0 0:8174d9ceeca1 45 /**************************************************************************/
arve0 0:8174d9ceeca1 46 uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg) {
arve0 0:8174d9ceeca1 47 char data[2];
arve0 0:8174d9ceeca1 48 data[0] = reg; // temporary use this to send address to conversion register
arve0 0:8174d9ceeca1 49 m_i2c->write(i2cAddress, data, 1);
arve0 0:8174d9ceeca1 50 m_i2c->read(i2cAddress, data, 2);
arve0 0:8174d9ceeca1 51 return (data[0] << 8 | data [1]);
arve0 0:8174d9ceeca1 52 }
arve0 0:8174d9ceeca1 53
arve0 0:8174d9ceeca1 54 /**************************************************************************/
arve0 0:8174d9ceeca1 55 /*!
arve0 0:8174d9ceeca1 56 @brief Instantiates a new ADS1015 class w/appropriate properties
arve0 0:8174d9ceeca1 57 */
arve0 0:8174d9ceeca1 58 /**************************************************************************/
arve0 0:8174d9ceeca1 59 Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress)
arve0 0:8174d9ceeca1 60 {
arve0 0:8174d9ceeca1 61 // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h
arve0 0:8174d9ceeca1 62 m_i2cAddress = i2cAddress << 1;
arve0 0:8174d9ceeca1 63 m_conversionDelay = ADS1015_CONVERSIONDELAY;
arve0 0:8174d9ceeca1 64 m_bitShift = 4;
arve0 0:8174d9ceeca1 65 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
arve0 0:8174d9ceeca1 66 m_i2c = i2c;
arve0 0:8174d9ceeca1 67 }
arve0 0:8174d9ceeca1 68
arve0 0:8174d9ceeca1 69 /**************************************************************************/
arve0 0:8174d9ceeca1 70 /*!
arve0 0:8174d9ceeca1 71 @brief Instantiates a new ADS1115 class w/appropriate properties
arve0 0:8174d9ceeca1 72 */
arve0 0:8174d9ceeca1 73 /**************************************************************************/
arve0 0:8174d9ceeca1 74 Adafruit_ADS1115::Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress)
arve0 0:8174d9ceeca1 75 {
arve0 0:8174d9ceeca1 76 // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h
arve0 0:8174d9ceeca1 77 m_i2cAddress = i2cAddress << 1;
arve0 0:8174d9ceeca1 78 m_conversionDelay = ADS1115_CONVERSIONDELAY;
arve0 0:8174d9ceeca1 79 m_bitShift = 0;
arve0 0:8174d9ceeca1 80 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
arve0 0:8174d9ceeca1 81 m_i2c = i2c;
arve0 0:8174d9ceeca1 82 }
arve0 0:8174d9ceeca1 83
arve0 0:8174d9ceeca1 84 /**************************************************************************/
arve0 0:8174d9ceeca1 85 /*!
arve0 0:8174d9ceeca1 86 @brief Sets the gain and input voltage range
arve0 0:8174d9ceeca1 87 */
arve0 0:8174d9ceeca1 88 /**************************************************************************/
arve0 0:8174d9ceeca1 89 void Adafruit_ADS1015::setGain(adsGain_t gain)
arve0 0:8174d9ceeca1 90 {
arve0 0:8174d9ceeca1 91 m_gain = gain;
arve0 0:8174d9ceeca1 92 }
arve0 0:8174d9ceeca1 93
arve0 0:8174d9ceeca1 94 /**************************************************************************/
arve0 0:8174d9ceeca1 95 /*!
arve0 0:8174d9ceeca1 96 @brief Gets a gain and input voltage range
arve0 0:8174d9ceeca1 97 */
arve0 0:8174d9ceeca1 98 /**************************************************************************/
arve0 0:8174d9ceeca1 99 adsGain_t Adafruit_ADS1015::getGain()
arve0 0:8174d9ceeca1 100 {
arve0 0:8174d9ceeca1 101 return m_gain;
arve0 0:8174d9ceeca1 102 }
arve0 0:8174d9ceeca1 103
arve0 0:8174d9ceeca1 104 /**************************************************************************/
arve0 0:8174d9ceeca1 105 /*!
arve0 0:8174d9ceeca1 106 @brief Gets a single-ended ADC reading from the specified channel
arve0 0:8174d9ceeca1 107 */
arve0 0:8174d9ceeca1 108 /**************************************************************************/
arve0 0:8174d9ceeca1 109 uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel) {
arve0 0:8174d9ceeca1 110 if (channel > 3)
arve0 0:8174d9ceeca1 111 {
arve0 0:8174d9ceeca1 112 return 0;
arve0 0:8174d9ceeca1 113 }
arve0 0:8174d9ceeca1 114
arve0 0:8174d9ceeca1 115 // Start with default values
arve0 0:8174d9ceeca1 116 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 0:8174d9ceeca1 117 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 0:8174d9ceeca1 118 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 0:8174d9ceeca1 119 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 0:8174d9ceeca1 120 ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default)
arve0 0:8174d9ceeca1 121 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 122
arve0 0:8174d9ceeca1 123 // Set PGA/voltage range
arve0 0:8174d9ceeca1 124 config |= m_gain;
arve0 0:8174d9ceeca1 125
arve0 0:8174d9ceeca1 126 // Set single-ended input channel
arve0 0:8174d9ceeca1 127 switch (channel)
arve0 0:8174d9ceeca1 128 {
arve0 0:8174d9ceeca1 129 case (0):
arve0 0:8174d9ceeca1 130 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 0:8174d9ceeca1 131 break;
arve0 0:8174d9ceeca1 132 case (1):
arve0 0:8174d9ceeca1 133 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 0:8174d9ceeca1 134 break;
arve0 0:8174d9ceeca1 135 case (2):
arve0 0:8174d9ceeca1 136 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 0:8174d9ceeca1 137 break;
arve0 0:8174d9ceeca1 138 case (3):
arve0 0:8174d9ceeca1 139 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 0:8174d9ceeca1 140 break;
arve0 0:8174d9ceeca1 141 }
arve0 0:8174d9ceeca1 142
arve0 0:8174d9ceeca1 143 // Set 'start single-conversion' bit
arve0 0:8174d9ceeca1 144 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 145
arve0 0:8174d9ceeca1 146 // Write config register to the ADC
arve0 0:8174d9ceeca1 147 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 148
arve0 0:8174d9ceeca1 149 // Wait for the conversion to complete
arve0 0:8174d9ceeca1 150 wait_ms(m_conversionDelay);
arve0 0:8174d9ceeca1 151
arve0 0:8174d9ceeca1 152 // Read the conversion results
arve0 0:8174d9ceeca1 153 // Shift 12-bit results right 4 bits for the ADS1015
arve0 0:8174d9ceeca1 154 return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 0:8174d9ceeca1 155 }
arve0 0:8174d9ceeca1 156
arve0 0:8174d9ceeca1 157 /**************************************************************************/
arve0 0:8174d9ceeca1 158 /*!
arve0 0:8174d9ceeca1 159 @brief Reads the conversion results, measuring the voltage
arve0 0:8174d9ceeca1 160 difference between the P (AIN0) and N (AIN1) input. Generates
arve0 0:8174d9ceeca1 161 a signed value since the difference can be either
arve0 0:8174d9ceeca1 162 positive or negative.
arve0 0:8174d9ceeca1 163 */
arve0 0:8174d9ceeca1 164 /**************************************************************************/
arve0 0:8174d9ceeca1 165 int16_t Adafruit_ADS1015::readADC_Differential_0_1() {
arve0 0:8174d9ceeca1 166 // Start with default values
arve0 0:8174d9ceeca1 167 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 0:8174d9ceeca1 168 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 0:8174d9ceeca1 169 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 0:8174d9ceeca1 170 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 0:8174d9ceeca1 171 ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default)
arve0 0:8174d9ceeca1 172 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 173
arve0 0:8174d9ceeca1 174 // Set PGA/voltage range
arve0 0:8174d9ceeca1 175 config |= m_gain;
arve0 0:8174d9ceeca1 176
arve0 0:8174d9ceeca1 177 // Set channels
arve0 0:8174d9ceeca1 178 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N
arve0 0:8174d9ceeca1 179
arve0 0:8174d9ceeca1 180 // Set 'start single-conversion' bit
arve0 0:8174d9ceeca1 181 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 182
arve0 0:8174d9ceeca1 183 // Write config register to the ADC
arve0 0:8174d9ceeca1 184 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 185
arve0 0:8174d9ceeca1 186 // Wait for the conversion to complete
arve0 0:8174d9ceeca1 187 wait_ms(m_conversionDelay);
arve0 0:8174d9ceeca1 188
arve0 0:8174d9ceeca1 189 // Read the conversion results
arve0 0:8174d9ceeca1 190 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 0:8174d9ceeca1 191 if (m_bitShift == 0)
arve0 0:8174d9ceeca1 192 {
arve0 0:8174d9ceeca1 193 return (int16_t)res;
arve0 0:8174d9ceeca1 194 }
arve0 0:8174d9ceeca1 195 else
arve0 0:8174d9ceeca1 196 {
arve0 0:8174d9ceeca1 197 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 0:8174d9ceeca1 198 // making sure we keep the sign bit intact
arve0 0:8174d9ceeca1 199 if (res > 0x07FF)
arve0 0:8174d9ceeca1 200 {
arve0 0:8174d9ceeca1 201 // negative number - extend the sign to 16th bit
arve0 0:8174d9ceeca1 202 res |= 0xF000;
arve0 0:8174d9ceeca1 203 }
arve0 0:8174d9ceeca1 204 return (int16_t)res;
arve0 0:8174d9ceeca1 205 }
arve0 0:8174d9ceeca1 206 }
arve0 0:8174d9ceeca1 207
arve0 0:8174d9ceeca1 208 /**************************************************************************/
arve0 0:8174d9ceeca1 209 /*!
arve0 0:8174d9ceeca1 210 @brief Reads the conversion results, measuring the voltage
arve0 0:8174d9ceeca1 211 difference between the P (AIN2) and N (AIN3) input. Generates
arve0 0:8174d9ceeca1 212 a signed value since the difference can be either
arve0 0:8174d9ceeca1 213 positive or negative.
arve0 0:8174d9ceeca1 214 */
arve0 0:8174d9ceeca1 215 /**************************************************************************/
arve0 0:8174d9ceeca1 216 int16_t Adafruit_ADS1015::readADC_Differential_2_3() {
arve0 0:8174d9ceeca1 217 // Start with default values
arve0 0:8174d9ceeca1 218 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 0:8174d9ceeca1 219 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 0:8174d9ceeca1 220 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 0:8174d9ceeca1 221 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 0:8174d9ceeca1 222 ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default)
arve0 0:8174d9ceeca1 223 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 224
arve0 0:8174d9ceeca1 225 // Set PGA/voltage range
arve0 0:8174d9ceeca1 226 config |= m_gain;
arve0 0:8174d9ceeca1 227
arve0 0:8174d9ceeca1 228 // Set channels
arve0 0:8174d9ceeca1 229 config |= ADS1015_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N
arve0 0:8174d9ceeca1 230
arve0 0:8174d9ceeca1 231 // Set 'start single-conversion' bit
arve0 0:8174d9ceeca1 232 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 233
arve0 0:8174d9ceeca1 234 // Write config register to the ADC
arve0 0:8174d9ceeca1 235 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 236
arve0 0:8174d9ceeca1 237 // Wait for the conversion to complete
arve0 0:8174d9ceeca1 238 wait_ms(m_conversionDelay);
arve0 0:8174d9ceeca1 239
arve0 0:8174d9ceeca1 240 // Read the conversion results
arve0 0:8174d9ceeca1 241 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 0:8174d9ceeca1 242 if (m_bitShift == 0)
arve0 0:8174d9ceeca1 243 {
arve0 0:8174d9ceeca1 244 return (int16_t)res;
arve0 0:8174d9ceeca1 245 }
arve0 0:8174d9ceeca1 246 else
arve0 0:8174d9ceeca1 247 {
arve0 0:8174d9ceeca1 248 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 0:8174d9ceeca1 249 // making sure we keep the sign bit intact
arve0 0:8174d9ceeca1 250 if (res > 0x07FF)
arve0 0:8174d9ceeca1 251 {
arve0 0:8174d9ceeca1 252 // negative number - extend the sign to 16th bit
arve0 0:8174d9ceeca1 253 res |= 0xF000;
arve0 0:8174d9ceeca1 254 }
arve0 0:8174d9ceeca1 255 return (int16_t)res;
arve0 0:8174d9ceeca1 256 }
arve0 0:8174d9ceeca1 257 }
arve0 0:8174d9ceeca1 258
arve0 0:8174d9ceeca1 259 /**************************************************************************/
arve0 0:8174d9ceeca1 260 /*!
arve0 0:8174d9ceeca1 261 @brief Sets up the comparator to operate in basic mode, causing the
arve0 0:8174d9ceeca1 262 ALERT/RDY pin to assert (go from high to low) when the ADC
arve0 0:8174d9ceeca1 263 value exceeds the specified threshold.
arve0 0:8174d9ceeca1 264
arve0 0:8174d9ceeca1 265 This will also set the ADC in continuous conversion mode.
arve0 0:8174d9ceeca1 266 */
arve0 0:8174d9ceeca1 267 /**************************************************************************/
arve0 0:8174d9ceeca1 268 void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold)
arve0 0:8174d9ceeca1 269 {
arve0 0:8174d9ceeca1 270 // Start with default values
arve0 0:8174d9ceeca1 271 uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match
arve0 0:8174d9ceeca1 272 ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode
arve0 0:8174d9ceeca1 273 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 0:8174d9ceeca1 274 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 0:8174d9ceeca1 275 ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default)
arve0 0:8174d9ceeca1 276 ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode
arve0 0:8174d9ceeca1 277 ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode
arve0 0:8174d9ceeca1 278
arve0 0:8174d9ceeca1 279 // Set PGA/voltage range
arve0 0:8174d9ceeca1 280 config |= m_gain;
arve0 0:8174d9ceeca1 281
arve0 0:8174d9ceeca1 282 // Set single-ended input channel
arve0 0:8174d9ceeca1 283 switch (channel)
arve0 0:8174d9ceeca1 284 {
arve0 0:8174d9ceeca1 285 case (0):
arve0 0:8174d9ceeca1 286 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 0:8174d9ceeca1 287 break;
arve0 0:8174d9ceeca1 288 case (1):
arve0 0:8174d9ceeca1 289 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 0:8174d9ceeca1 290 break;
arve0 0:8174d9ceeca1 291 case (2):
arve0 0:8174d9ceeca1 292 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 0:8174d9ceeca1 293 break;
arve0 0:8174d9ceeca1 294 case (3):
arve0 0:8174d9ceeca1 295 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 0:8174d9ceeca1 296 break;
arve0 0:8174d9ceeca1 297 }
arve0 0:8174d9ceeca1 298
arve0 0:8174d9ceeca1 299 // Set the high threshold register
arve0 0:8174d9ceeca1 300 // Shift 12-bit results left 4 bits for the ADS1015
arve0 0:8174d9ceeca1 301 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift);
arve0 0:8174d9ceeca1 302
arve0 0:8174d9ceeca1 303 // Write config register to the ADC
arve0 0:8174d9ceeca1 304 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 305 }
arve0 0:8174d9ceeca1 306
arve0 0:8174d9ceeca1 307 /**************************************************************************/
arve0 0:8174d9ceeca1 308 /*!
arve0 0:8174d9ceeca1 309 @brief In order to clear the comparator, we need to read the
arve0 0:8174d9ceeca1 310 conversion results. This function reads the last conversion
arve0 0:8174d9ceeca1 311 results without changing the config value.
arve0 0:8174d9ceeca1 312 */
arve0 0:8174d9ceeca1 313 /**************************************************************************/
arve0 0:8174d9ceeca1 314 int16_t Adafruit_ADS1015::getLastConversionResults()
arve0 0:8174d9ceeca1 315 {
arve0 0:8174d9ceeca1 316 // Wait for the conversion to complete
arve0 0:8174d9ceeca1 317 wait_ms(m_conversionDelay);
arve0 0:8174d9ceeca1 318
arve0 0:8174d9ceeca1 319 // Read the conversion results
arve0 0:8174d9ceeca1 320 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 0:8174d9ceeca1 321 if (m_bitShift == 0)
arve0 0:8174d9ceeca1 322 {
arve0 0:8174d9ceeca1 323 return (int16_t)res;
arve0 0:8174d9ceeca1 324 }
arve0 0:8174d9ceeca1 325 else
arve0 0:8174d9ceeca1 326 {
arve0 0:8174d9ceeca1 327 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 0:8174d9ceeca1 328 // making sure we keep the sign bit intact
arve0 0:8174d9ceeca1 329 if (res > 0x07FF)
arve0 0:8174d9ceeca1 330 {
arve0 0:8174d9ceeca1 331 // negative number - extend the sign to 16th bit
arve0 0:8174d9ceeca1 332 res |= 0xF000;
arve0 0:8174d9ceeca1 333 }
arve0 0:8174d9ceeca1 334 return (int16_t)res;
arve0 0:8174d9ceeca1 335 }
arve0 0:8174d9ceeca1 336 }