etienne maillet / Adafruit_ADS1015

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Adafruit_ADS1015.cpp@0:4dd9af114f46, 2019-03-06 (annotated)

Committer:
etiene32
Date:
Wed Mar 06 10:46:05 2019 +0000
Revision:
0:4dd9af114f46
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etiene32 0:4dd9af114f46 1 /**************************************************************************/
etiene32 0:4dd9af114f46 2 /*!
etiene32 0:4dd9af114f46 3 @file Adafruit_ADS1015.cpp
etiene32 0:4dd9af114f46 4 @author K.Townsend (Adafruit Industries)
etiene32 0:4dd9af114f46 5 @license BSD (see LICENSE.txt)
etiene32 0:4dd9af114f46 6
etiene32 0:4dd9af114f46 7 Ported to mbed by Arve Seljebu - arve0.github.io
etiene32 0:4dd9af114f46 8
etiene32 0:4dd9af114f46 9 Driver for the ADS1015/ADS1115 ADC
etiene32 0:4dd9af114f46 10
etiene32 0:4dd9af114f46 11 This is a library for the Adafruit MPL115A2 breakout
etiene32 0:4dd9af114f46 12 ----> https://www.adafruit.com/products/1083
etiene32 0:4dd9af114f46 13
etiene32 0:4dd9af114f46 14 Adafruit invests time and resources providing this open source code,
etiene32 0:4dd9af114f46 15 please support Adafruit and open-source hardware by purchasing
etiene32 0:4dd9af114f46 16 products from Adafruit!
etiene32 0:4dd9af114f46 17
etiene32 0:4dd9af114f46 18 @section HISTORY
etiene32 0:4dd9af114f46 19
etiene32 0:4dd9af114f46 20 v1.0 - First release
etiene32 0:4dd9af114f46 21 v1.1.1 - Ported to mbed
etiene32 0:4dd9af114f46 22 */
etiene32 0:4dd9af114f46 23 /**************************************************************************/
etiene32 0:4dd9af114f46 24
etiene32 0:4dd9af114f46 25 #include <mbed.h>
etiene32 0:4dd9af114f46 26 #include "Adafruit_ADS1015.h"
etiene32 0:4dd9af114f46 27
etiene32 0:4dd9af114f46 28 /**************************************************************************/
etiene32 0:4dd9af114f46 29 /*!
etiene32 0:4dd9af114f46 30 @brief Writes 16-bits to the specified destination register
etiene32 0:4dd9af114f46 31 */
etiene32 0:4dd9af114f46 32 /**************************************************************************/
etiene32 0:4dd9af114f46 33 void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value)
etiene32 0:4dd9af114f46 34 {
etiene32 0:4dd9af114f46 35 char cmd[3];
etiene32 0:4dd9af114f46 36 cmd[0] = (char)reg;
etiene32 0:4dd9af114f46 37 cmd[1] = (char)(value>>8);
etiene32 0:4dd9af114f46 38 cmd[2] = (char)(value & 0xFF);
etiene32 0:4dd9af114f46 39 m_i2c->write(i2cAddress, cmd, 3);
etiene32 0:4dd9af114f46 40 }
etiene32 0:4dd9af114f46 41
etiene32 0:4dd9af114f46 42 /**************************************************************************/
etiene32 0:4dd9af114f46 43 /*!
etiene32 0:4dd9af114f46 44 @brief Reads 16-bits from the specified register
etiene32 0:4dd9af114f46 45 */
etiene32 0:4dd9af114f46 46 /**************************************************************************/
etiene32 0:4dd9af114f46 47 uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg)
etiene32 0:4dd9af114f46 48 {
etiene32 0:4dd9af114f46 49 char data[2];
etiene32 0:4dd9af114f46 50 data[0] = reg; // temporary use this to send address to conversion register
etiene32 0:4dd9af114f46 51 m_i2c->write(i2cAddress, data, 1);
etiene32 0:4dd9af114f46 52 m_i2c->read(i2cAddress, data, 2);
etiene32 0:4dd9af114f46 53 return (data[0] << 8 | data [1]);
etiene32 0:4dd9af114f46 54 }
etiene32 0:4dd9af114f46 55
etiene32 0:4dd9af114f46 56 /**************************************************************************/
etiene32 0:4dd9af114f46 57 /*!
etiene32 0:4dd9af114f46 58 @brief Instantiates a new ADS1015 class w/appropriate properties
etiene32 0:4dd9af114f46 59 */
etiene32 0:4dd9af114f46 60 /**************************************************************************/
etiene32 0:4dd9af114f46 61 Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress)
etiene32 0:4dd9af114f46 62 {
etiene32 0:4dd9af114f46 63 // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h
etiene32 0:4dd9af114f46 64 m_i2cAddress = i2cAddress << 1;
etiene32 0:4dd9af114f46 65 m_conversionDelay = ADS1015_CONVERSIONDELAY;
etiene32 0:4dd9af114f46 66 m_bitShift = 4;
etiene32 0:4dd9af114f46 67 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
etiene32 0:4dd9af114f46 68 m_i2c = i2c;
etiene32 0:4dd9af114f46 69 }
etiene32 0:4dd9af114f46 70
etiene32 0:4dd9af114f46 71 /**************************************************************************/
etiene32 0:4dd9af114f46 72 /*!
etiene32 0:4dd9af114f46 73 @brief Instantiates a new ADS1115 class w/appropriate properties
etiene32 0:4dd9af114f46 74 */
etiene32 0:4dd9af114f46 75 /**************************************************************************/
etiene32 0:4dd9af114f46 76 Adafruit_ADS1115::Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress)
etiene32 0:4dd9af114f46 77 {
etiene32 0:4dd9af114f46 78 // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h
etiene32 0:4dd9af114f46 79 m_i2cAddress = i2cAddress << 1;
etiene32 0:4dd9af114f46 80 m_conversionDelay = ADS1115_CONVERSIONDELAY;
etiene32 0:4dd9af114f46 81 m_bitShift = 0;
etiene32 0:4dd9af114f46 82 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
etiene32 0:4dd9af114f46 83 m_i2c = i2c;
etiene32 0:4dd9af114f46 84 }
etiene32 0:4dd9af114f46 85
etiene32 0:4dd9af114f46 86 /**************************************************************************/
etiene32 0:4dd9af114f46 87 /*!
etiene32 0:4dd9af114f46 88 @brief Sets the gain and input voltage range
etiene32 0:4dd9af114f46 89 */
etiene32 0:4dd9af114f46 90 /**************************************************************************/
etiene32 0:4dd9af114f46 91 void Adafruit_ADS1015::setGain(adsGain_t gain)
etiene32 0:4dd9af114f46 92 {
etiene32 0:4dd9af114f46 93 m_gain = gain;
etiene32 0:4dd9af114f46 94 }
etiene32 0:4dd9af114f46 95
etiene32 0:4dd9af114f46 96 /**************************************************************************/
etiene32 0:4dd9af114f46 97 /*!
etiene32 0:4dd9af114f46 98 @brief Gets a gain and input voltage range
etiene32 0:4dd9af114f46 99 */
etiene32 0:4dd9af114f46 100 /**************************************************************************/
etiene32 0:4dd9af114f46 101 adsGain_t Adafruit_ADS1015::getGain()
etiene32 0:4dd9af114f46 102 {
etiene32 0:4dd9af114f46 103 return m_gain;
etiene32 0:4dd9af114f46 104 }
etiene32 0:4dd9af114f46 105
etiene32 0:4dd9af114f46 106 /**************************************************************************/
etiene32 0:4dd9af114f46 107 /*!
etiene32 0:4dd9af114f46 108 @brief Gets a single-ended ADC reading from the specified channel
etiene32 0:4dd9af114f46 109 */
etiene32 0:4dd9af114f46 110 /**************************************************************************/
etiene32 0:4dd9af114f46 111 uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel)
etiene32 0:4dd9af114f46 112 {
etiene32 0:4dd9af114f46 113 if (channel > 3) {
etiene32 0:4dd9af114f46 114 return 0;
etiene32 0:4dd9af114f46 115 }
etiene32 0:4dd9af114f46 116
etiene32 0:4dd9af114f46 117 // Start with default values
etiene32 0:4dd9af114f46 118 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
etiene32 0:4dd9af114f46 119 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
etiene32 0:4dd9af114f46 120 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
etiene32 0:4dd9af114f46 121 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
etiene32 0:4dd9af114f46 122 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
etiene32 0:4dd9af114f46 123 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
etiene32 0:4dd9af114f46 124
etiene32 0:4dd9af114f46 125 // Set PGA/voltage range
etiene32 0:4dd9af114f46 126 config |= m_gain;
etiene32 0:4dd9af114f46 127
etiene32 0:4dd9af114f46 128 // Set single-ended input channel
etiene32 0:4dd9af114f46 129 switch (channel) {
etiene32 0:4dd9af114f46 130 case (0):
etiene32 0:4dd9af114f46 131 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
etiene32 0:4dd9af114f46 132 break;
etiene32 0:4dd9af114f46 133 case (1):
etiene32 0:4dd9af114f46 134 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
etiene32 0:4dd9af114f46 135 break;
etiene32 0:4dd9af114f46 136 case (2):
etiene32 0:4dd9af114f46 137 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
etiene32 0:4dd9af114f46 138 break;
etiene32 0:4dd9af114f46 139 case (3):
etiene32 0:4dd9af114f46 140 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
etiene32 0:4dd9af114f46 141 break;
etiene32 0:4dd9af114f46 142 }
etiene32 0:4dd9af114f46 143
etiene32 0:4dd9af114f46 144 // Set 'start single-conversion' bit
etiene32 0:4dd9af114f46 145 config |= ADS1015_REG_CONFIG_OS_SINGLE;
etiene32 0:4dd9af114f46 146
etiene32 0:4dd9af114f46 147 // Write config register to the ADC
etiene32 0:4dd9af114f46 148 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
etiene32 0:4dd9af114f46 149
etiene32 0:4dd9af114f46 150 // Wait for the conversion to complete
etiene32 0:4dd9af114f46 151 wait_ms(m_conversionDelay);
etiene32 0:4dd9af114f46 152
etiene32 0:4dd9af114f46 153 // Read the conversion results
etiene32 0:4dd9af114f46 154 // Shift 12-bit results right 4 bits for the ADS1015
etiene32 0:4dd9af114f46 155 return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
etiene32 0:4dd9af114f46 156 }
etiene32 0:4dd9af114f46 157
etiene32 0:4dd9af114f46 158 /**************************************************************************/
etiene32 0:4dd9af114f46 159 /*!
etiene32 0:4dd9af114f46 160 @brief Reads the conversion results, measuring the voltage
etiene32 0:4dd9af114f46 161 difference between the P (AIN0) and N (AIN1) input. Generates
etiene32 0:4dd9af114f46 162 a signed value since the difference can be either
etiene32 0:4dd9af114f46 163 positive or negative.
etiene32 0:4dd9af114f46 164 */
etiene32 0:4dd9af114f46 165 /**************************************************************************/
etiene32 0:4dd9af114f46 166 int16_t Adafruit_ADS1015::readADC_Differential_0_1()
etiene32 0:4dd9af114f46 167 {
etiene32 0:4dd9af114f46 168 // Start with default values
etiene32 0:4dd9af114f46 169 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
etiene32 0:4dd9af114f46 170 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
etiene32 0:4dd9af114f46 171 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
etiene32 0:4dd9af114f46 172 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
etiene32 0:4dd9af114f46 173 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
etiene32 0:4dd9af114f46 174 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
etiene32 0:4dd9af114f46 175
etiene32 0:4dd9af114f46 176 // Set PGA/voltage range
etiene32 0:4dd9af114f46 177 config |= m_gain;
etiene32 0:4dd9af114f46 178
etiene32 0:4dd9af114f46 179 // Set channels
etiene32 0:4dd9af114f46 180 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N
etiene32 0:4dd9af114f46 181
etiene32 0:4dd9af114f46 182 // Set 'start single-conversion' bit
etiene32 0:4dd9af114f46 183 config |= ADS1015_REG_CONFIG_OS_SINGLE;
etiene32 0:4dd9af114f46 184
etiene32 0:4dd9af114f46 185 // Write config register to the ADC
etiene32 0:4dd9af114f46 186 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
etiene32 0:4dd9af114f46 187
etiene32 0:4dd9af114f46 188 // Wait for the conversion to complete
etiene32 0:4dd9af114f46 189 wait_ms(m_conversionDelay);
etiene32 0:4dd9af114f46 190
etiene32 0:4dd9af114f46 191 // Read the conversion results
etiene32 0:4dd9af114f46 192 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
etiene32 0:4dd9af114f46 193 if (m_bitShift == 0) {
etiene32 0:4dd9af114f46 194 return (int16_t)res;
etiene32 0:4dd9af114f46 195 } else {
etiene32 0:4dd9af114f46 196 // Shift 12-bit results right 4 bits for the ADS1015,
etiene32 0:4dd9af114f46 197 // making sure we keep the sign bit intact
etiene32 0:4dd9af114f46 198 if (res > 0x07FF) {
etiene32 0:4dd9af114f46 199 // negative number - extend the sign to 16th bit
etiene32 0:4dd9af114f46 200 res |= 0xF000;
etiene32 0:4dd9af114f46 201 }
etiene32 0:4dd9af114f46 202 return (int16_t)res;
etiene32 0:4dd9af114f46 203 }
etiene32 0:4dd9af114f46 204 }
etiene32 0:4dd9af114f46 205
etiene32 0:4dd9af114f46 206 /**************************************************************************/
etiene32 0:4dd9af114f46 207 /*!
etiene32 0:4dd9af114f46 208 @brief Reads the conversion results, measuring the voltage
etiene32 0:4dd9af114f46 209 difference between the P (AIN2) and N (AIN3) input. Generates
etiene32 0:4dd9af114f46 210 a signed value since the difference can be either
etiene32 0:4dd9af114f46 211 positive or negative.
etiene32 0:4dd9af114f46 212 */
etiene32 0:4dd9af114f46 213 /**************************************************************************/
etiene32 0:4dd9af114f46 214 int16_t Adafruit_ADS1015::readADC_Differential_2_3()
etiene32 0:4dd9af114f46 215 {
etiene32 0:4dd9af114f46 216 // Start with default values
etiene32 0:4dd9af114f46 217 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
etiene32 0:4dd9af114f46 218 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
etiene32 0:4dd9af114f46 219 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
etiene32 0:4dd9af114f46 220 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
etiene32 0:4dd9af114f46 221 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
etiene32 0:4dd9af114f46 222 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
etiene32 0:4dd9af114f46 223
etiene32 0:4dd9af114f46 224 // Set PGA/voltage range
etiene32 0:4dd9af114f46 225 config |= m_gain;
etiene32 0:4dd9af114f46 226
etiene32 0:4dd9af114f46 227 // Set channels
etiene32 0:4dd9af114f46 228 config |= ADS1015_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N
etiene32 0:4dd9af114f46 229
etiene32 0:4dd9af114f46 230 // Set 'start single-conversion' bit
etiene32 0:4dd9af114f46 231 config |= ADS1015_REG_CONFIG_OS_SINGLE;
etiene32 0:4dd9af114f46 232
etiene32 0:4dd9af114f46 233 // Write config register to the ADC
etiene32 0:4dd9af114f46 234 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
etiene32 0:4dd9af114f46 235
etiene32 0:4dd9af114f46 236 // Wait for the conversion to complete
etiene32 0:4dd9af114f46 237 wait_ms(m_conversionDelay);
etiene32 0:4dd9af114f46 238
etiene32 0:4dd9af114f46 239 // Read the conversion results
etiene32 0:4dd9af114f46 240 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
etiene32 0:4dd9af114f46 241 if (m_bitShift == 0) {
etiene32 0:4dd9af114f46 242 return (int16_t)res;
etiene32 0:4dd9af114f46 243 } else {
etiene32 0:4dd9af114f46 244 // Shift 12-bit results right 4 bits for the ADS1015,
etiene32 0:4dd9af114f46 245 // making sure we keep the sign bit intact
etiene32 0:4dd9af114f46 246 if (res > 0x07FF) {
etiene32 0:4dd9af114f46 247 // negative number - extend the sign to 16th bit
etiene32 0:4dd9af114f46 248 res |= 0xF000;
etiene32 0:4dd9af114f46 249 }
etiene32 0:4dd9af114f46 250 return (int16_t)res;
etiene32 0:4dd9af114f46 251 }
etiene32 0:4dd9af114f46 252 }
etiene32 0:4dd9af114f46 253
etiene32 0:4dd9af114f46 254 /**************************************************************************/
etiene32 0:4dd9af114f46 255 /*!
etiene32 0:4dd9af114f46 256 @brief Sets up the comparator to operate in basic mode, causing the
etiene32 0:4dd9af114f46 257 ALERT/RDY pin to assert (go from high to low) when the ADC
etiene32 0:4dd9af114f46 258 value exceeds the specified threshold.
etiene32 0:4dd9af114f46 259
etiene32 0:4dd9af114f46 260 This will also set the ADC in continuous conversion mode.
etiene32 0:4dd9af114f46 261 */
etiene32 0:4dd9af114f46 262 /**************************************************************************/
etiene32 0:4dd9af114f46 263 void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold)
etiene32 0:4dd9af114f46 264 {
etiene32 0:4dd9af114f46 265 // Start with default values
etiene32 0:4dd9af114f46 266 uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match
etiene32 0:4dd9af114f46 267 ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode
etiene32 0:4dd9af114f46 268 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
etiene32 0:4dd9af114f46 269 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
etiene32 0:4dd9af114f46 270 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
etiene32 0:4dd9af114f46 271 ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode
etiene32 0:4dd9af114f46 272 ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode
etiene32 0:4dd9af114f46 273
etiene32 0:4dd9af114f46 274 // Set PGA/voltage range
etiene32 0:4dd9af114f46 275 config |= m_gain;
etiene32 0:4dd9af114f46 276
etiene32 0:4dd9af114f46 277 // Set single-ended input channel
etiene32 0:4dd9af114f46 278 switch (channel) {
etiene32 0:4dd9af114f46 279 case (0):
etiene32 0:4dd9af114f46 280 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
etiene32 0:4dd9af114f46 281 break;
etiene32 0:4dd9af114f46 282 case (1):
etiene32 0:4dd9af114f46 283 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
etiene32 0:4dd9af114f46 284 break;
etiene32 0:4dd9af114f46 285 case (2):
etiene32 0:4dd9af114f46 286 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
etiene32 0:4dd9af114f46 287 break;
etiene32 0:4dd9af114f46 288 case (3):
etiene32 0:4dd9af114f46 289 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
etiene32 0:4dd9af114f46 290 break;
etiene32 0:4dd9af114f46 291 }
etiene32 0:4dd9af114f46 292
etiene32 0:4dd9af114f46 293 // Set the high threshold register
etiene32 0:4dd9af114f46 294 // Shift 12-bit results left 4 bits for the ADS1015
etiene32 0:4dd9af114f46 295 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift);
etiene32 0:4dd9af114f46 296
etiene32 0:4dd9af114f46 297 // Write config register to the ADC
etiene32 0:4dd9af114f46 298 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
etiene32 0:4dd9af114f46 299 }
etiene32 0:4dd9af114f46 300
etiene32 0:4dd9af114f46 301 /**************************************************************************/
etiene32 0:4dd9af114f46 302 /*!
etiene32 0:4dd9af114f46 303 @brief In order to clear the comparator, we need to read the
etiene32 0:4dd9af114f46 304 conversion results. This function reads the last conversion
etiene32 0:4dd9af114f46 305 results without changing the config value.
etiene32 0:4dd9af114f46 306 */
etiene32 0:4dd9af114f46 307 /**************************************************************************/
etiene32 0:4dd9af114f46 308 int16_t Adafruit_ADS1015::getLastConversionResults()
etiene32 0:4dd9af114f46 309 {
etiene32 0:4dd9af114f46 310 // Wait for the conversion to complete
etiene32 0:4dd9af114f46 311 wait_ms(m_conversionDelay);
etiene32 0:4dd9af114f46 312
etiene32 0:4dd9af114f46 313 // Read the conversion results
etiene32 0:4dd9af114f46 314 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
etiene32 0:4dd9af114f46 315 if (m_bitShift == 0) {
etiene32 0:4dd9af114f46 316 return (int16_t)res;
etiene32 0:4dd9af114f46 317 } else {
etiene32 0:4dd9af114f46 318 // Shift 12-bit results right 4 bits for the ADS1015,
etiene32 0:4dd9af114f46 319 // making sure we keep the sign bit intact
etiene32 0:4dd9af114f46 320 if (res > 0x07FF) {
etiene32 0:4dd9af114f46 321 // negative number - extend the sign to 16th bit
etiene32 0:4dd9af114f46 322 res |= 0xF000;
etiene32 0:4dd9af114f46 323 }
etiene32 0:4dd9af114f46 324 return (int16_t)res;
etiene32 0:4dd9af114f46 325 }
etiene32 0:4dd9af114f46 326 }