BAP TUDelft / ADS1015

Library for the ADS1015 and ADS1115 ADCS

Fork of ADS1015 by Momo-Medical

Adafruit_ADS1015.cpp@16:a9e5edacbaf7, 2018-06-05 (annotated)

Committer:
xorjoep
Date:
Tue Jun 05 14:18:10 2018 +0000
Revision:
16:a9e5edacbaf7
Parent:
14:e8dd6dcf64e9
Child:
18:4b4e3446cdd4
upped readout speed + started writing double electric readout function

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 int16_t * Adafruit_ADS1015::readADC_Differential_DoubleEnded(){
xorjoep 16:a9e5edacbaf7 107
xorjoep 16:a9e5edacbaf7 108 int16_t temp_res;
xorjoep 16:a9e5edacbaf7 109 int16_t results[2];
xorjoep 16:a9e5edacbaf7 110
xorjoep 16:a9e5edacbaf7 111 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
xorjoep 16:a9e5edacbaf7 112 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
xorjoep 16:a9e5edacbaf7 113 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
xorjoep 16:a9e5edacbaf7 114 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 16:a9e5edacbaf7 115 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
xorjoep 16:a9e5edacbaf7 116 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
xorjoep 16:a9e5edacbaf7 117
xorjoep 16:a9e5edacbaf7 118 // Set PGA/voltage range
xorjoep 16:a9e5edacbaf7 119 config |= m_gain;
xorjoep 16:a9e5edacbaf7 120
xorjoep 16:a9e5edacbaf7 121 // Set channels
xorjoep 16:a9e5edacbaf7 122 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_3; // AIN0 = P, AIN1 = N
xorjoep 16:a9e5edacbaf7 123
xorjoep 16:a9e5edacbaf7 124 // Set 'start single-conversion' bit
xorjoep 16:a9e5edacbaf7 125 config |= ADS1015_REG_CONFIG_OS_SINGLE;
xorjoep 16:a9e5edacbaf7 126
xorjoep 16:a9e5edacbaf7 127 // Read the first
xorjoep 16:a9e5edacbaf7 128 temp_res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
xorjoep 16:a9e5edacbaf7 129
xorjoep 16:a9e5edacbaf7 130 if (m_bitShift != 0) {
xorjoep 16:a9e5edacbaf7 131 // Shift 12-bit results right 4 bits for the ADS1015,
xorjoep 16:a9e5edacbaf7 132 // making sure we keep the sign bit intact
xorjoep 16:a9e5edacbaf7 133 if (temp_res > 0x07FF) {
xorjoep 16:a9e5edacbaf7 134 // negative number - extend the sign to 16th bit
xorjoep 16:a9e5edacbaf7 135 temp_res |= 0xF000;
xorjoep 16:a9e5edacbaf7 136 }
xorjoep 16:a9e5edacbaf7 137 }
xorjoep 16:a9e5edacbaf7 138 results[0] = temp_res;
xorjoep 16:a9e5edacbaf7 139
xorjoep 16:a9e5edacbaf7 140
xorjoep 16:a9e5edacbaf7 141 // Write config register to the ADC
xorjoep 16:a9e5edacbaf7 142 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
xorjoep 16:a9e5edacbaf7 143
xorjoep 16:a9e5edacbaf7 144 // Wait for the conversion to complete
xorjoep 16:a9e5edacbaf7 145 wait_us(m_conversionDelay);
xorjoep 16:a9e5edacbaf7 146
xorjoep 16:a9e5edacbaf7 147 // Read the conversion results
xorjoep 16:a9e5edacbaf7 148 temp_res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
xorjoep 16:a9e5edacbaf7 149
xorjoep 16:a9e5edacbaf7 150 if (m_bitShift != 0) {
xorjoep 16:a9e5edacbaf7 151 // Shift 12-bit results right 4 bits for the ADS1015,
xorjoep 16:a9e5edacbaf7 152 // making sure we keep the sign bit intact
xorjoep 16:a9e5edacbaf7 153 if (temp_res > 0x07FF) {
xorjoep 16:a9e5edacbaf7 154 // negative number - extend the sign to 16th bit
xorjoep 16:a9e5edacbaf7 155 temp_res |= 0xF000;
xorjoep 16:a9e5edacbaf7 156 }
xorjoep 16:a9e5edacbaf7 157 }
xorjoep 16:a9e5edacbaf7 158 results[1] |= temp_res;
xorjoep 16:a9e5edacbaf7 159
xorjoep 16:a9e5edacbaf7 160 config |= ADS1015_REG_CONFIG_MUX_DIFF_1_3;
xorjoep 16:a9e5edacbaf7 161
xorjoep 16:a9e5edacbaf7 162 // Write config register to the ADC
xorjoep 16:a9e5edacbaf7 163 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
xorjoep 16:a9e5edacbaf7 164
xorjoep 16:a9e5edacbaf7 165 return results;
xorjoep 16:a9e5edacbaf7 166 }
xorjoep 16:a9e5edacbaf7 167
arve0 0:8174d9ceeca1 168 /**************************************************************************/
arve0 0:8174d9ceeca1 169 /*!
arve0 0:8174d9ceeca1 170 @brief Gets a single-ended ADC reading from the specified channel
arve0 0:8174d9ceeca1 171 */
arve0 0:8174d9ceeca1 172 /**************************************************************************/
arve0 3:fb735fb343de 173 uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel)
arve0 3:fb735fb343de 174 {
arve0 3:fb735fb343de 175 if (channel > 3) {
arve0 3:fb735fb343de 176 return 0;
arve0 3:fb735fb343de 177 }
arve0 0:8174d9ceeca1 178
arve0 3:fb735fb343de 179 // Start with default values
arve0 3:fb735fb343de 180 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 181 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 182 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 183 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
DEldering 6:e6fecdc96fb1 184 ADS1015_REG_CONFIG_DR_3300SPS | // 860(ADS1115) samples per second
arve0 3:fb735fb343de 185 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 3:fb735fb343de 186
arve0 3:fb735fb343de 187 // Set PGA/voltage range
arve0 3:fb735fb343de 188 config |= m_gain;
arve0 0:8174d9ceeca1 189
arve0 3:fb735fb343de 190 // Set single-ended input channel
arve0 3:fb735fb343de 191 switch (channel) {
arve0 3:fb735fb343de 192 case (0):
arve0 3:fb735fb343de 193 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 3:fb735fb343de 194 break;
arve0 3:fb735fb343de 195 case (1):
arve0 3:fb735fb343de 196 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 3:fb735fb343de 197 break;
arve0 3:fb735fb343de 198 case (2):
arve0 3:fb735fb343de 199 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 3:fb735fb343de 200 break;
arve0 3:fb735fb343de 201 case (3):
arve0 3:fb735fb343de 202 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 3:fb735fb343de 203 break;
arve0 3:fb735fb343de 204 }
arve0 0:8174d9ceeca1 205
arve0 3:fb735fb343de 206 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 207 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 208
arve0 3:fb735fb343de 209 // Write config register to the ADC
arve0 3:fb735fb343de 210 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 211
arve0 3:fb735fb343de 212 // Wait for the conversion to complete
DEldering 10:da5d0da65437 213 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 214
arve0 3:fb735fb343de 215 // Read the conversion results
arve0 3:fb735fb343de 216 // Shift 12-bit results right 4 bits for the ADS1015
DEldering 10:da5d0da65437 217 return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
DEldering 10:da5d0da65437 218 // return 1;
arve0 0:8174d9ceeca1 219 }
arve0 0:8174d9ceeca1 220
arve0 0:8174d9ceeca1 221 /**************************************************************************/
arve0 3:fb735fb343de 222 /*!
arve0 0:8174d9ceeca1 223 @brief Reads the conversion results, measuring the voltage
arve0 0:8174d9ceeca1 224 difference between the P (AIN0) and N (AIN1) input. Generates
arve0 0:8174d9ceeca1 225 a signed value since the difference can be either
arve0 0:8174d9ceeca1 226 positive or negative.
arve0 0:8174d9ceeca1 227 */
arve0 0:8174d9ceeca1 228 /**************************************************************************/
xorjoep 13:e0d3c07d79fa 229 int16_t Adafruit_ADS1015::readADC_Differential_0_3()
arve0 3:fb735fb343de 230 {
arve0 3:fb735fb343de 231 // Start with default values
arve0 3:fb735fb343de 232 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 233 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 234 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 235 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 14:e8dd6dcf64e9 236 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 237 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 238
arve0 3:fb735fb343de 239 // Set PGA/voltage range
arve0 3:fb735fb343de 240 config |= m_gain;
arve0 0:8174d9ceeca1 241
arve0 3:fb735fb343de 242 // Set channels
xorjoep 13:e0d3c07d79fa 243 config |= ADS1015_REG_CONFIG_MUX_DIFF_0_3; // AIN0 = P, AIN1 = N
arve0 0:8174d9ceeca1 244
arve0 3:fb735fb343de 245 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 246 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 247
arve0 3:fb735fb343de 248 // Write config register to the ADC
arve0 3:fb735fb343de 249 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 3:fb735fb343de 250
arve0 3:fb735fb343de 251 // Wait for the conversion to complete
deldering95 12:b8485d232bf8 252 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 253
arve0 3:fb735fb343de 254 // Read the conversion results
arve0 3:fb735fb343de 255 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 256 if (m_bitShift == 0) {
arve0 3:fb735fb343de 257 return (int16_t)res;
arve0 3:fb735fb343de 258 } else {
arve0 3:fb735fb343de 259 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 260 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 261 if (res > 0x07FF) {
arve0 3:fb735fb343de 262 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 263 res |= 0xF000;
arve0 3:fb735fb343de 264 }
arve0 3:fb735fb343de 265 return (int16_t)res;
arve0 0:8174d9ceeca1 266 }
arve0 0:8174d9ceeca1 267 }
arve0 0:8174d9ceeca1 268
arve0 0:8174d9ceeca1 269 /**************************************************************************/
arve0 3:fb735fb343de 270 /*!
arve0 0:8174d9ceeca1 271 @brief Reads the conversion results, measuring the voltage
arve0 0:8174d9ceeca1 272 difference between the P (AIN2) and N (AIN3) input. Generates
arve0 0:8174d9ceeca1 273 a signed value since the difference can be either
arve0 0:8174d9ceeca1 274 positive or negative.
arve0 0:8174d9ceeca1 275 */
arve0 0:8174d9ceeca1 276 /**************************************************************************/
xorjoep 13:e0d3c07d79fa 277 int16_t Adafruit_ADS1015::readADC_Differential_1_3()
arve0 3:fb735fb343de 278 {
arve0 3:fb735fb343de 279 // Start with default values
arve0 3:fb735fb343de 280 uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val)
arve0 3:fb735fb343de 281 ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val)
arve0 3:fb735fb343de 282 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 283 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
xorjoep 14:e8dd6dcf64e9 284 ADS1015_REG_CONFIG_DR_3300SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 285 ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default)
arve0 0:8174d9ceeca1 286
arve0 3:fb735fb343de 287 // Set PGA/voltage range
arve0 3:fb735fb343de 288 config |= m_gain;
arve0 0:8174d9ceeca1 289
arve0 3:fb735fb343de 290 // Set channels
xorjoep 13:e0d3c07d79fa 291 config |= ADS1015_REG_CONFIG_MUX_DIFF_1_3; // AIN0 = P, AIN1 = N
arve0 0:8174d9ceeca1 292
arve0 3:fb735fb343de 293 // Set 'start single-conversion' bit
arve0 3:fb735fb343de 294 config |= ADS1015_REG_CONFIG_OS_SINGLE;
arve0 0:8174d9ceeca1 295
arve0 3:fb735fb343de 296 // Write config register to the ADC
arve0 3:fb735fb343de 297 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 3:fb735fb343de 298
arve0 3:fb735fb343de 299 // Wait for the conversion to complete
xorjoep 13:e0d3c07d79fa 300 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 301
arve0 3:fb735fb343de 302 // Read the conversion results
arve0 3:fb735fb343de 303 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 304 if (m_bitShift == 0) {
arve0 3:fb735fb343de 305 return (int16_t)res;
arve0 3:fb735fb343de 306 } else {
arve0 3:fb735fb343de 307 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 308 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 309 if (res > 0x07FF) {
arve0 3:fb735fb343de 310 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 311 res |= 0xF000;
arve0 3:fb735fb343de 312 }
arve0 3:fb735fb343de 313 return (int16_t)res;
arve0 0:8174d9ceeca1 314 }
arve0 0:8174d9ceeca1 315 }
arve0 0:8174d9ceeca1 316 /**************************************************************************/
arve0 0:8174d9ceeca1 317 /*!
arve0 0:8174d9ceeca1 318 @brief Sets up the comparator to operate in basic mode, causing the
arve0 0:8174d9ceeca1 319 ALERT/RDY pin to assert (go from high to low) when the ADC
arve0 0:8174d9ceeca1 320 value exceeds the specified threshold.
arve0 0:8174d9ceeca1 321
arve0 0:8174d9ceeca1 322 This will also set the ADC in continuous conversion mode.
arve0 0:8174d9ceeca1 323 */
arve0 0:8174d9ceeca1 324 /**************************************************************************/
arve0 0:8174d9ceeca1 325 void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold)
arve0 0:8174d9ceeca1 326 {
arve0 3:fb735fb343de 327 // Start with default values
arve0 3:fb735fb343de 328 uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match
arve0 3:fb735fb343de 329 ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode
arve0 3:fb735fb343de 330 ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val)
arve0 3:fb735fb343de 331 ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val)
arve0 4:6445a678d458 332 ADS1015_REG_CONFIG_DR_1600SPS | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
arve0 3:fb735fb343de 333 ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode
arve0 3:fb735fb343de 334 ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode
arve0 3:fb735fb343de 335
arve0 3:fb735fb343de 336 // Set PGA/voltage range
arve0 3:fb735fb343de 337 config |= m_gain;
arve0 0:8174d9ceeca1 338
arve0 3:fb735fb343de 339 // Set single-ended input channel
arve0 3:fb735fb343de 340 switch (channel) {
arve0 3:fb735fb343de 341 case (0):
arve0 3:fb735fb343de 342 config |= ADS1015_REG_CONFIG_MUX_SINGLE_0;
arve0 3:fb735fb343de 343 break;
arve0 3:fb735fb343de 344 case (1):
arve0 3:fb735fb343de 345 config |= ADS1015_REG_CONFIG_MUX_SINGLE_1;
arve0 3:fb735fb343de 346 break;
arve0 3:fb735fb343de 347 case (2):
arve0 3:fb735fb343de 348 config |= ADS1015_REG_CONFIG_MUX_SINGLE_2;
arve0 3:fb735fb343de 349 break;
arve0 3:fb735fb343de 350 case (3):
arve0 3:fb735fb343de 351 config |= ADS1015_REG_CONFIG_MUX_SINGLE_3;
arve0 3:fb735fb343de 352 break;
arve0 3:fb735fb343de 353 }
arve0 0:8174d9ceeca1 354
arve0 3:fb735fb343de 355 // Set the high threshold register
arve0 3:fb735fb343de 356 // Shift 12-bit results left 4 bits for the ADS1015
arve0 3:fb735fb343de 357 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift);
arve0 0:8174d9ceeca1 358
arve0 3:fb735fb343de 359 // Write config register to the ADC
arve0 3:fb735fb343de 360 writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config);
arve0 0:8174d9ceeca1 361 }
arve0 0:8174d9ceeca1 362
arve0 0:8174d9ceeca1 363 /**************************************************************************/
arve0 0:8174d9ceeca1 364 /*!
arve0 0:8174d9ceeca1 365 @brief In order to clear the comparator, we need to read the
arve0 0:8174d9ceeca1 366 conversion results. This function reads the last conversion
arve0 0:8174d9ceeca1 367 results without changing the config value.
arve0 0:8174d9ceeca1 368 */
arve0 0:8174d9ceeca1 369 /**************************************************************************/
arve0 0:8174d9ceeca1 370 int16_t Adafruit_ADS1015::getLastConversionResults()
arve0 0:8174d9ceeca1 371 {
arve0 3:fb735fb343de 372 // Wait for the conversion to complete
xorjoep 16:a9e5edacbaf7 373 wait_us(m_conversionDelay);
arve0 0:8174d9ceeca1 374
arve0 3:fb735fb343de 375 // Read the conversion results
arve0 3:fb735fb343de 376 uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift;
arve0 3:fb735fb343de 377 if (m_bitShift == 0) {
arve0 3:fb735fb343de 378 return (int16_t)res;
arve0 3:fb735fb343de 379 } else {
arve0 3:fb735fb343de 380 // Shift 12-bit results right 4 bits for the ADS1015,
arve0 3:fb735fb343de 381 // making sure we keep the sign bit intact
arve0 3:fb735fb343de 382 if (res > 0x07FF) {
arve0 3:fb735fb343de 383 // negative number - extend the sign to 16th bit
arve0 3:fb735fb343de 384 res |= 0xF000;
arve0 3:fb735fb343de 385 }
arve0 3:fb735fb343de 386 return (int16_t)res;
arve0 0:8174d9ceeca1 387 }
arve0 3:fb735fb343de 388 }