BAP TUDelft / ADS1015

Library for the ADS1015 and ADS1115 ADCS

Fork of ADS1015 by Momo-Medical

Adafruit_ADS1015.cpp@20:277793ce35b2, 2018-06-21 (annotated)

Committer:
MockyBirdTwo
Date:
Thu Jun 21 15:49:53 2018 +0000
Revision:
20:277793ce35b2
Parent:
18:4b4e3446cdd4
Child:
21:1ed94c2550b2
idk2

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 3:fb735fb343de 33 void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value)
arve0 3:fb735fb343de 34 {
arve0 3:fb735fb343de 35 char cmd[3];
arve0 3:fb735fb343de 36 cmd[0] = (char)reg;
arve0 3:fb735fb343de 37 cmd[1] = (char)(value>>8);
arve0 3:fb735fb343de 38 cmd[2] = (char)(value & 0xFF);
arve0 3:fb735fb343de 39 m_i2c->write(i2cAddress, cmd, 3);
arve0 0:8174d9ceeca1 40 }
arve0 0:8174d9ceeca1 41
arve0 0:8174d9ceeca1 42 /**************************************************************************/
arve0 0:8174d9ceeca1 43 /*!
arve0 0:8174d9ceeca1 44 @brief Reads 16-bits from the specified register
arve0 0:8174d9ceeca1 45 */
arve0 0:8174d9ceeca1 46 /**************************************************************************/
arve0 3:fb735fb343de 47 uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg)
arve0 3:fb735fb343de 48 {
arve0 3:fb735fb343de 49 char data[2];
arve0 3:fb735fb343de 50 data[0] = reg; // temporary use this to send address to conversion register
arve0 3:fb735fb343de 51 m_i2c->write(i2cAddress, data, 1);
arve0 3:fb735fb343de 52 m_i2c->read(i2cAddress, data, 2);
arve0 3:fb735fb343de 53 return (data[0] << 8 | data [1]);
arve0 0:8174d9ceeca1 54 }
arve0 0:8174d9ceeca1 55
arve0 0:8174d9ceeca1 56 /**************************************************************************/
arve0 0:8174d9ceeca1 57 /*!
arve0 0:8174d9ceeca1 58 @brief Instantiates a new ADS1015 class w/appropriate properties
arve0 0:8174d9ceeca1 59 */
arve0 0:8174d9ceeca1 60 /**************************************************************************/
arve0 3:fb735fb343de 61 Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress)
arve0 0:8174d9ceeca1 62 {
arve0 3:fb735fb343de 63 // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h
arve0 3:fb735fb343de 64 m_i2cAddress = i2cAddress << 1;
arve0 3:fb735fb343de 65 m_conversionDelay = ADS1015_CONVERSIONDELAY;
arve0 3:fb735fb343de 66 m_bitShift = 4;
arve0 3:fb735fb343de 67 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
arve0 3:fb735fb343de 68 m_i2c = i2c;
arve0 0:8174d9ceeca1 69 }
arve0 0:8174d9ceeca1 70
arve0 0:8174d9ceeca1 71 /**************************************************************************/
arve0 0:8174d9ceeca1 72 /*!
arve0 0:8174d9ceeca1 73 @brief Instantiates a new ADS1115 class w/appropriate properties
arve0 0:8174d9ceeca1 74 */
arve0 0:8174d9ceeca1 75 /**************************************************************************/
arve0 0:8174d9ceeca1 76 Adafruit_ADS1115::Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress)
arve0 0:8174d9ceeca1 77 {
arve0 3:fb735fb343de 78 // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h
arve0 3:fb735fb343de 79 m_i2cAddress = i2cAddress << 1;
arve0 3:fb735fb343de 80 m_conversionDelay = ADS1115_CONVERSIONDELAY;
arve0 3:fb735fb343de 81 m_bitShift = 0;
arve0 3:fb735fb343de 82 m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
arve0 3:fb735fb343de 83 m_i2c = i2c;
arve0 0:8174d9ceeca1 84 }
arve0 0:8174d9ceeca1 85
arve0 0:8174d9ceeca1 86 /**************************************************************************/
arve0 0:8174d9ceeca1 87 /*!
arve0 0:8174d9ceeca1 88 @brief Sets the gain and input voltage range
arve0 0:8174d9ceeca1 89 */
arve0 0:8174d9ceeca1 90 /**************************************************************************/
arve0 0:8174d9ceeca1 91 void Adafruit_ADS1015::setGain(adsGain_t gain)
arve0 0:8174d9ceeca1 92 {
arve0 3:fb735fb343de 93 m_gain = gain;
arve0 0:8174d9ceeca1 94 }
arve0 0:8174d9ceeca1 95
arve0 0:8174d9ceeca1 96 /**************************************************************************/
arve0 0:8174d9ceeca1 97 /*!
arve0 0:8174d9ceeca1 98 @brief Gets a gain and input voltage range
arve0 0:8174d9ceeca1 99 */
arve0 0:8174d9ceeca1 100 /**************************************************************************/
arve0 0:8174d9ceeca1 101 adsGain_t Adafruit_ADS1015::getGain()
arve0 0:8174d9ceeca1 102 {
arve0 3:fb735fb343de 103 return m_gain;
arve0 0:8174d9ceeca1 104 }
arve0 0:8174d9ceeca1 105
xorjoep 16:a9e5edacbaf7 106
arve0 0:8174d9ceeca1 107 /**************************************************************************/
arve0 0:8174d9ceeca1 108 /*!
arve0 0:8174d9ceeca1 109 @brief Gets a single-ended ADC reading from the specified channel
arve0 0:8174d9ceeca1 110 */
arve0 0:8174d9ceeca1 111 /**************************************************************************/
arve0 3:fb735fb343de 112 uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel)
arve0 3:fb735fb343de 113 {
arve0 3:fb735fb343de 114 if (channel > 3) {
arve0 3:fb735fb343de 115 return 0;
arve0 3:fb735fb343de 116 }
arve0 0:8174d9ceeca1 117
arve0 3:fb735fb343de 118 // Start with default values
arve0 3:fb735fb343de 119 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 120 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 121 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 122 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
DEldering 6:e6fecdc96fb1 123 ADS1015_REG_CONFIG_DR_3300SPS | // 860(ADS1115) samples per second
arve0 3:fb735fb343de 124 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 3:fb735fb343de 125
arve0 3:fb735fb343de 126 // Set PGA/voltage range
arve0 3:fb735fb343de 127 config |= m_gain;
arve0 0:8174d9ceeca1 128
arve0 3:fb735fb343de 129 // Set single-ended input channel
arve0 3:fb735fb343de 130 switch (channel) {
arve0 3:fb735fb343de 131 case (0):
arve0 3:fb735fb343de 132 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 3:fb735fb343de 133 break;
arve0 3:fb735fb343de 134 case (1):
arve0 3:fb735fb343de 135 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 3:fb735fb343de 136 break;
arve0 3:fb735fb343de 137 case (2):
arve0 3:fb735fb343de 138 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 3:fb735fb343de 139 break;
arve0 3:fb735fb343de 140 case (3):
arve0 3:fb735fb343de 141 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 3:fb735fb343de 142 break;
arve0 3:fb735fb343de 143 }
arve0 0:8174d9ceeca1 144
arve0 3:fb735fb343de 145 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 146 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 147
arve0 3:fb735fb343de 148 // Write config register to the ADC
arve0 3:fb735fb343de 149 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 150
arve0 3:fb735fb343de 151 // Wait for the conversion to complete
DEldering 10:da5d0da65437 152 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 153
arve0 3:fb735fb343de 154 // Read the conversion results
arve0 3:fb735fb343de 155 // Shift 12-bit results right 4 bits for the ADS1015
DEldering 10:da5d0da65437 156 return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
DEldering 10:da5d0da65437 157 // return 1;
arve0 0:8174d9ceeca1 158 }
arve0 0:8174d9ceeca1 159
arve0 0:8174d9ceeca1 160 /**************************************************************************/
arve0 3:fb735fb343de 161 /*!
arve0 0:8174d9ceeca1 162 @brief Reads the conversion results, measuring the voltage
arve0 0:8174d9ceeca1 163 difference between the P (AIN0) and N (AIN1) input. Generates
arve0 0:8174d9ceeca1 164 a signed value since the difference can be either
arve0 0:8174d9ceeca1 165 positive or negative.
arve0 0:8174d9ceeca1 166 */
arve0 0:8174d9ceeca1 167 /**************************************************************************/
xorjoep 13:e0d3c07d79fa 168 int16_t Adafruit_ADS1015::readADC_Differential_0_3()
arve0 3:fb735fb343de 169 {
arve0 3:fb735fb343de 170 // Start with default values
arve0 3:fb735fb343de 171 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 172 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 173 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 174 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 14:e8dd6dcf64e9 175 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 176 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 177
arve0 3:fb735fb343de 178 // Set PGA/voltage range
arve0 3:fb735fb343de 179 config |= m_gain;
arve0 0:8174d9ceeca1 180
arve0 3:fb735fb343de 181 // Set channels
xorjoep 13:e0d3c07d79fa 182 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_3; // AIN0 = P, AIN1 = N
arve0 0:8174d9ceeca1 183
arve0 3:fb735fb343de 184 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 185 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 186
arve0 3:fb735fb343de 187 // Write config register to the ADC
arve0 3:fb735fb343de 188 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 3:fb735fb343de 189
arve0 3:fb735fb343de 190 // Wait for the conversion to complete
deldering95 12:b8485d232bf8 191 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 192
arve0 3:fb735fb343de 193 // Read the conversion results
arve0 3:fb735fb343de 194 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 195 if (m_bitShift == 0) {
arve0 3:fb735fb343de 196 return (int16_t)res;
arve0 3:fb735fb343de 197 } else {
arve0 3:fb735fb343de 198 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 199 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 200 if (res > 0x07FF) {
arve0 3:fb735fb343de 201 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 202 res |= 0xF000;
arve0 3:fb735fb343de 203 }
arve0 3:fb735fb343de 204 return (int16_t)res;
arve0 0:8174d9ceeca1 205 }
arve0 0:8174d9ceeca1 206 }
arve0 0:8174d9ceeca1 207
arve0 0:8174d9ceeca1 208 /**************************************************************************/
arve0 3:fb735fb343de 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 /**************************************************************************/
xorjoep 13:e0d3c07d79fa 216 int16_t Adafruit_ADS1015::readADC_Differential_1_3()
arve0 3:fb735fb343de 217 {
arve0 3:fb735fb343de 218 // Start with default values
arve0 3:fb735fb343de 219 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 220 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 221 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 222 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 14:e8dd6dcf64e9 223 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 224 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 225
arve0 3:fb735fb343de 226 // Set PGA/voltage range
arve0 3:fb735fb343de 227 config |= m_gain;
arve0 0:8174d9ceeca1 228
arve0 3:fb735fb343de 229 // Set channels
xorjoep 13:e0d3c07d79fa 230 config |= ADS1015_REG_CONFIG_MUX_DIFF_1_3; // AIN0 = P, AIN1 = N
arve0 0:8174d9ceeca1 231
arve0 3:fb735fb343de 232 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 233 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 234
arve0 3:fb735fb343de 235 // Write config register to the ADC
arve0 3:fb735fb343de 236 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 3:fb735fb343de 237
arve0 3:fb735fb343de 238 // Wait for the conversion to complete
xorjoep 13:e0d3c07d79fa 239 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 240
arve0 3:fb735fb343de 241 // Read the conversion results
arve0 3:fb735fb343de 242 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 243 if (m_bitShift == 0) {
arve0 3:fb735fb343de 244 return (int16_t)res;
arve0 3:fb735fb343de 245 } else {
arve0 3:fb735fb343de 246 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 247 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 248 if (res > 0x07FF) {
arve0 3:fb735fb343de 249 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 250 res |= 0xF000;
arve0 3:fb735fb343de 251 }
arve0 3:fb735fb343de 252 return (int16_t)res;
arve0 0:8174d9ceeca1 253 }
arve0 0:8174d9ceeca1 254 }
xorjoep 15:e659b715ed89 255 int16_t * Adafruit_ADS1015::readADC_Differential_DoubleEnded(){
xorjoep 15:e659b715ed89 256
xorjoep 15:e659b715ed89 257 uint16_t temp_res;
xorjoep 15:e659b715ed89 258 static int16_t results[2];
xorjoep 15:e659b715ed89 259
xorjoep 15:e659b715ed89 260 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
xorjoep 15:e659b715ed89 261 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
xorjoep 15:e659b715ed89 262 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
xorjoep 15:e659b715ed89 263 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 15:e659b715ed89 264 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
xorjoep 15:e659b715ed89 265 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
xorjoep 15:e659b715ed89 266
xorjoep 15:e659b715ed89 267 // Set PGA/voltage range
xorjoep 15:e659b715ed89 268 config |= m_gain;
xorjoep 15:e659b715ed89 269
xorjoep 15:e659b715ed89 270 // Set channels
xorjoep 15:e659b715ed89 271 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_3; // AIN0 = P, AIN1 = N
xorjoep 15:e659b715ed89 272
xorjoep 15:e659b715ed89 273 // Set 'start single-conversion' bit
xorjoep 15:e659b715ed89 274 config |= ADS1015_REG_CONFIG_OS_SINGLE;
xorjoep 15:e659b715ed89 275
xorjoep 15:e659b715ed89 276 // // Read the first
xorjoep 15:e659b715ed89 277 // temp_res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
xorjoep 15:e659b715ed89 278 //
xorjoep 15:e659b715ed89 279 // if (m_bitShift != 0) {
xorjoep 15:e659b715ed89 280 // // Shift 12-bit results right 4 bits for the ADS1015,
xorjoep 15:e659b715ed89 281 // // making sure we keep the sign bit intact
xorjoep 15:e659b715ed89 282 // if (temp_res > 0x07FF) {
xorjoep 15:e659b715ed89 283 // // negative number - extend the sign to 16th bit
xorjoep 15:e659b715ed89 284 // temp_res |= 0xF000;
xorjoep 15:e659b715ed89 285 // }
xorjoep 15:e659b715ed89 286 // }
xorjoep 15:e659b715ed89 287 // results[0] = temp_res;
xorjoep 15:e659b715ed89 288
xorjoep 15:e659b715ed89 289
xorjoep 15:e659b715ed89 290 // Write config register to the ADC
xorjoep 15:e659b715ed89 291 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
xorjoep 15:e659b715ed89 292
xorjoep 15:e659b715ed89 293 // Wait for the conversion to complete
xorjoep 15:e659b715ed89 294 wait_us(m_conversionDelay);
xorjoep 15:e659b715ed89 295
xorjoep 15:e659b715ed89 296 // Read the conversion results
xorjoep 15:e659b715ed89 297 temp_res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
xorjoep 15:e659b715ed89 298
xorjoep 15:e659b715ed89 299 if (m_bitShift != 0) {
xorjoep 15:e659b715ed89 300 // Shift 12-bit results right 4 bits for the ADS1015,
xorjoep 15:e659b715ed89 301 // making sure we keep the sign bit intact
xorjoep 15:e659b715ed89 302 if (temp_res > 0x07FF) {
xorjoep 15:e659b715ed89 303 // negative number - extend the sign to 16th bit
xorjoep 15:e659b715ed89 304 temp_res |= 0xF000;
xorjoep 15:e659b715ed89 305 }
xorjoep 15:e659b715ed89 306 }
xorjoep 15:e659b715ed89 307 results[1] |= (int16_t) temp_res;
xorjoep 15:e659b715ed89 308
xorjoep 15:e659b715ed89 309 //config |= ADS1015_REG_CONFIG_MUX_DIFF_1_3;
xorjoep 15:e659b715ed89 310 //
xorjoep 15:e659b715ed89 311 // // Write config register to the ADC
xorjoep 15:e659b715ed89 312 // writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
xorjoep 15:e659b715ed89 313
xorjoep 15:e659b715ed89 314 return results;
xorjoep 15:e659b715ed89 315 }
xorjoep 15:e659b715ed89 316
arve0 0:8174d9ceeca1 317 /**************************************************************************/
arve0 0:8174d9ceeca1 318 /*!
arve0 0:8174d9ceeca1 319 @brief Sets up the comparator to operate in basic mode, causing the
arve0 0:8174d9ceeca1 320 ALERT/RDY pin to assert (go from high to low) when the ADC
arve0 0:8174d9ceeca1 321 value exceeds the specified threshold.
arve0 0:8174d9ceeca1 322
arve0 0:8174d9ceeca1 323 This will also set the ADC in continuous conversion mode.
arve0 0:8174d9ceeca1 324 */
arve0 0:8174d9ceeca1 325 /**************************************************************************/
arve0 0:8174d9ceeca1 326 void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold)
arve0 0:8174d9ceeca1 327 {
arve0 3:fb735fb343de 328 // Start with default values
arve0 3:fb735fb343de 329 uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match
arve0 3:fb735fb343de 330 ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode
arve0 3:fb735fb343de 331 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 332 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 4:6445a678d458 333 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 334 ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode
arve0 3:fb735fb343de 335 ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode
arve0 3:fb735fb343de 336
arve0 3:fb735fb343de 337 // Set PGA/voltage range
arve0 3:fb735fb343de 338 config |= m_gain;
arve0 0:8174d9ceeca1 339
arve0 3:fb735fb343de 340 // Set single-ended input channel
arve0 3:fb735fb343de 341 switch (channel) {
arve0 3:fb735fb343de 342 case (0):
arve0 3:fb735fb343de 343 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 3:fb735fb343de 344 break;
arve0 3:fb735fb343de 345 case (1):
arve0 3:fb735fb343de 346 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 3:fb735fb343de 347 break;
arve0 3:fb735fb343de 348 case (2):
arve0 3:fb735fb343de 349 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 3:fb735fb343de 350 break;
arve0 3:fb735fb343de 351 case (3):
arve0 3:fb735fb343de 352 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 3:fb735fb343de 353 break;
arve0 3:fb735fb343de 354 }
arve0 0:8174d9ceeca1 355
arve0 3:fb735fb343de 356 // Set the high threshold register
arve0 3:fb735fb343de 357 // Shift 12-bit results left 4 bits for the ADS1015
arve0 3:fb735fb343de 358 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift);
arve0 0:8174d9ceeca1 359
arve0 3:fb735fb343de 360 // Write config register to the ADC
arve0 3:fb735fb343de 361 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 362 }
arve0 0:8174d9ceeca1 363
arve0 0:8174d9ceeca1 364 /**************************************************************************/
arve0 0:8174d9ceeca1 365 /*!
arve0 0:8174d9ceeca1 366 @brief In order to clear the comparator, we need to read the
arve0 0:8174d9ceeca1 367 conversion results. This function reads the last conversion
arve0 0:8174d9ceeca1 368 results without changing the config value.
arve0 0:8174d9ceeca1 369 */
arve0 0:8174d9ceeca1 370 /**************************************************************************/
arve0 0:8174d9ceeca1 371 int16_t Adafruit_ADS1015::getLastConversionResults()
arve0 0:8174d9ceeca1 372 {
arve0 3:fb735fb343de 373 // Wait for the conversion to complete
xorjoep 15:e659b715ed89 374 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 375
arve0 3:fb735fb343de 376 // Read the conversion results
arve0 3:fb735fb343de 377 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 378 if (m_bitShift == 0) {
arve0 3:fb735fb343de 379 return (int16_t)res;
arve0 3:fb735fb343de 380 } else {
arve0 3:fb735fb343de 381 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 382 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 383 if (res > 0x07FF) {
arve0 3:fb735fb343de 384 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 385 res |= 0xF000;
arve0 3:fb735fb343de 386 }
arve0 3:fb735fb343de 387 return (int16_t)res;
arve0 0:8174d9ceeca1 388 }
arve0 3:fb735fb343de 389 }