A library for ADS1015 and ADS1115 from Texas Instruments.
Fork of ADS1015 by
v1.3 - Added ADS1115_REG_CONFIG_DR & m_dataRate Jul 21. 2014 - Corrected m_conversionDelay - Now there is readADC() that returns counts and readADC_V() that returns voltage
Adafruit_ADS1015.cpp@1:a628fdaed351, 2014-05-21 (annotated)
- Committer:
- Sambo007
- Date:
- Wed May 21 13:12:24 2014 +0000
- Revision:
- 1:a628fdaed351
- Parent:
- 0:8174d9ceeca1
v1.2 - Fixed error in readADC_SingleEnded() sign bit
Who changed what in which revision?
User | Revision | Line number | New 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 | |
Sambo007 | 1:a628fdaed351 | 20 | v1.0 - First release |
Sambo007 | 1:a628fdaed351 | 21 | v1.1 - Added ADS1115 support - W. Earl |
Sambo007 | 1:a628fdaed351 | 22 | v1.1.1 - Ported to mbed - Arve Seljebu |
Sambo007 | 1:a628fdaed351 | 23 | v1.2 - Fixed error in readADC_SingleEnded() sign bit - Sam Berjawi |
arve0 | 0:8174d9ceeca1 | 24 | */ |
arve0 | 0:8174d9ceeca1 | 25 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 26 | |
arve0 | 0:8174d9ceeca1 | 27 | #include <mbed.h> |
arve0 | 0:8174d9ceeca1 | 28 | #include "Adafruit_ADS1015.h" |
arve0 | 0:8174d9ceeca1 | 29 | |
arve0 | 0:8174d9ceeca1 | 30 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 31 | /*! |
arve0 | 0:8174d9ceeca1 | 32 | @brief Writes 16-bits to the specified destination register |
arve0 | 0:8174d9ceeca1 | 33 | */ |
arve0 | 0:8174d9ceeca1 | 34 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 35 | void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value) { |
arve0 | 0:8174d9ceeca1 | 36 | char cmd[3]; |
arve0 | 0:8174d9ceeca1 | 37 | cmd[0] = (char)reg; |
arve0 | 0:8174d9ceeca1 | 38 | cmd[1] = (char)(value>>8); |
arve0 | 0:8174d9ceeca1 | 39 | cmd[2] = (char)(value & 0xFF); |
arve0 | 0:8174d9ceeca1 | 40 | m_i2c->write(i2cAddress, cmd, 3); |
arve0 | 0:8174d9ceeca1 | 41 | } |
arve0 | 0:8174d9ceeca1 | 42 | |
arve0 | 0:8174d9ceeca1 | 43 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 44 | /*! |
arve0 | 0:8174d9ceeca1 | 45 | @brief Reads 16-bits from the specified register |
arve0 | 0:8174d9ceeca1 | 46 | */ |
arve0 | 0:8174d9ceeca1 | 47 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 48 | uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg) { |
arve0 | 0:8174d9ceeca1 | 49 | char data[2]; |
arve0 | 0:8174d9ceeca1 | 50 | data[0] = reg; // temporary use this to send address to conversion register |
arve0 | 0:8174d9ceeca1 | 51 | m_i2c->write(i2cAddress, data, 1); |
arve0 | 0:8174d9ceeca1 | 52 | m_i2c->read(i2cAddress, data, 2); |
arve0 | 0:8174d9ceeca1 | 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 | 0:8174d9ceeca1 | 61 | Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress) |
arve0 | 0:8174d9ceeca1 | 62 | { |
arve0 | 0:8174d9ceeca1 | 63 | // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h |
arve0 | 0:8174d9ceeca1 | 64 | m_i2cAddress = i2cAddress << 1; |
arve0 | 0:8174d9ceeca1 | 65 | m_conversionDelay = ADS1015_CONVERSIONDELAY; |
arve0 | 0:8174d9ceeca1 | 66 | m_bitShift = 4; |
arve0 | 0:8174d9ceeca1 | 67 | m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */ |
arve0 | 0:8174d9ceeca1 | 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 | 0:8174d9ceeca1 | 78 | // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h |
arve0 | 0:8174d9ceeca1 | 79 | m_i2cAddress = i2cAddress << 1; |
arve0 | 0:8174d9ceeca1 | 80 | m_conversionDelay = ADS1115_CONVERSIONDELAY; |
arve0 | 0:8174d9ceeca1 | 81 | m_bitShift = 0; |
arve0 | 0:8174d9ceeca1 | 82 | m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */ |
arve0 | 0:8174d9ceeca1 | 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 | 0:8174d9ceeca1 | 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 | 0:8174d9ceeca1 | 103 | return m_gain; |
arve0 | 0:8174d9ceeca1 | 104 | } |
arve0 | 0:8174d9ceeca1 | 105 | |
arve0 | 0:8174d9ceeca1 | 106 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 107 | /*! |
arve0 | 0:8174d9ceeca1 | 108 | @brief Gets a single-ended ADC reading from the specified channel |
arve0 | 0:8174d9ceeca1 | 109 | */ |
arve0 | 0:8174d9ceeca1 | 110 | /**************************************************************************/ |
Sambo007 | 1:a628fdaed351 | 111 | //uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel) { SWB |
Sambo007 | 1:a628fdaed351 | 112 | int16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel) { |
arve0 | 0:8174d9ceeca1 | 113 | if (channel > 3) |
arve0 | 0:8174d9ceeca1 | 114 | { |
arve0 | 0:8174d9ceeca1 | 115 | return 0; |
arve0 | 0:8174d9ceeca1 | 116 | } |
arve0 | 0:8174d9ceeca1 | 117 | |
arve0 | 0:8174d9ceeca1 | 118 | // Start with default values |
arve0 | 0:8174d9ceeca1 | 119 | uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) |
arve0 | 0:8174d9ceeca1 | 120 | ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) |
arve0 | 0:8174d9ceeca1 | 121 | ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) |
arve0 | 0:8174d9ceeca1 | 122 | ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) |
arve0 | 0:8174d9ceeca1 | 123 | ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) |
arve0 | 0:8174d9ceeca1 | 124 | ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) |
arve0 | 0:8174d9ceeca1 | 125 | |
arve0 | 0:8174d9ceeca1 | 126 | // Set PGA/voltage range |
arve0 | 0:8174d9ceeca1 | 127 | config |= m_gain; |
arve0 | 0:8174d9ceeca1 | 128 | |
arve0 | 0:8174d9ceeca1 | 129 | // Set single-ended input channel |
arve0 | 0:8174d9ceeca1 | 130 | switch (channel) |
arve0 | 0:8174d9ceeca1 | 131 | { |
arve0 | 0:8174d9ceeca1 | 132 | case (0): |
arve0 | 0:8174d9ceeca1 | 133 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_0; |
arve0 | 0:8174d9ceeca1 | 134 | break; |
arve0 | 0:8174d9ceeca1 | 135 | case (1): |
arve0 | 0:8174d9ceeca1 | 136 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_1; |
arve0 | 0:8174d9ceeca1 | 137 | break; |
arve0 | 0:8174d9ceeca1 | 138 | case (2): |
arve0 | 0:8174d9ceeca1 | 139 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_2; |
arve0 | 0:8174d9ceeca1 | 140 | break; |
arve0 | 0:8174d9ceeca1 | 141 | case (3): |
arve0 | 0:8174d9ceeca1 | 142 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_3; |
arve0 | 0:8174d9ceeca1 | 143 | break; |
arve0 | 0:8174d9ceeca1 | 144 | } |
arve0 | 0:8174d9ceeca1 | 145 | |
arve0 | 0:8174d9ceeca1 | 146 | // Set 'start single-conversion' bit |
arve0 | 0:8174d9ceeca1 | 147 | config |= ADS1015_REG_CONFIG_OS_SINGLE; |
arve0 | 0:8174d9ceeca1 | 148 | |
arve0 | 0:8174d9ceeca1 | 149 | // Write config register to the ADC |
arve0 | 0:8174d9ceeca1 | 150 | writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); |
arve0 | 0:8174d9ceeca1 | 151 | |
arve0 | 0:8174d9ceeca1 | 152 | // Wait for the conversion to complete |
arve0 | 0:8174d9ceeca1 | 153 | wait_ms(m_conversionDelay); |
arve0 | 0:8174d9ceeca1 | 154 | |
arve0 | 0:8174d9ceeca1 | 155 | // Read the conversion results |
arve0 | 0:8174d9ceeca1 | 156 | // Shift 12-bit results right 4 bits for the ADS1015 |
Sambo007 | 1:a628fdaed351 | 157 | //return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; SWB |
Sambo007 | 1:a628fdaed351 | 158 | |
Sambo007 | 1:a628fdaed351 | 159 | // SWB |
Sambo007 | 1:a628fdaed351 | 160 | // Shift 12-bit results right 4 bits for the ADS1015 |
Sambo007 | 1:a628fdaed351 | 161 | uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; |
Sambo007 | 1:a628fdaed351 | 162 | |
Sambo007 | 1:a628fdaed351 | 163 | if (m_bitShift == 0) |
Sambo007 | 1:a628fdaed351 | 164 | { |
Sambo007 | 1:a628fdaed351 | 165 | return (int16_t)res; |
Sambo007 | 1:a628fdaed351 | 166 | } |
Sambo007 | 1:a628fdaed351 | 167 | else |
Sambo007 | 1:a628fdaed351 | 168 | { |
Sambo007 | 1:a628fdaed351 | 169 | // Shift 12-bit results right 4 bits for the ADS1015, |
Sambo007 | 1:a628fdaed351 | 170 | // making sure we keep the sign bit intact |
Sambo007 | 1:a628fdaed351 | 171 | if (res > 0x07FF) |
Sambo007 | 1:a628fdaed351 | 172 | { |
Sambo007 | 1:a628fdaed351 | 173 | // negative number - extend the sign to 16th bit |
Sambo007 | 1:a628fdaed351 | 174 | res |= 0xF000; |
Sambo007 | 1:a628fdaed351 | 175 | } |
Sambo007 | 1:a628fdaed351 | 176 | return (int16_t)res; |
Sambo007 | 1:a628fdaed351 | 177 | } |
arve0 | 0:8174d9ceeca1 | 178 | } |
arve0 | 0:8174d9ceeca1 | 179 | |
arve0 | 0:8174d9ceeca1 | 180 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 181 | /*! |
arve0 | 0:8174d9ceeca1 | 182 | @brief Reads the conversion results, measuring the voltage |
arve0 | 0:8174d9ceeca1 | 183 | difference between the P (AIN0) and N (AIN1) input. Generates |
arve0 | 0:8174d9ceeca1 | 184 | a signed value since the difference can be either |
arve0 | 0:8174d9ceeca1 | 185 | positive or negative. |
arve0 | 0:8174d9ceeca1 | 186 | */ |
arve0 | 0:8174d9ceeca1 | 187 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 188 | int16_t Adafruit_ADS1015::readADC_Differential_0_1() { |
arve0 | 0:8174d9ceeca1 | 189 | // Start with default values |
arve0 | 0:8174d9ceeca1 | 190 | uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) |
arve0 | 0:8174d9ceeca1 | 191 | ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) |
arve0 | 0:8174d9ceeca1 | 192 | ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) |
arve0 | 0:8174d9ceeca1 | 193 | ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) |
arve0 | 0:8174d9ceeca1 | 194 | ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) |
arve0 | 0:8174d9ceeca1 | 195 | ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) |
arve0 | 0:8174d9ceeca1 | 196 | |
arve0 | 0:8174d9ceeca1 | 197 | // Set PGA/voltage range |
arve0 | 0:8174d9ceeca1 | 198 | config |= m_gain; |
arve0 | 0:8174d9ceeca1 | 199 | |
arve0 | 0:8174d9ceeca1 | 200 | // Set channels |
arve0 | 0:8174d9ceeca1 | 201 | config |= ADS1015_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N |
arve0 | 0:8174d9ceeca1 | 202 | |
arve0 | 0:8174d9ceeca1 | 203 | // Set 'start single-conversion' bit |
arve0 | 0:8174d9ceeca1 | 204 | config |= ADS1015_REG_CONFIG_OS_SINGLE; |
arve0 | 0:8174d9ceeca1 | 205 | |
arve0 | 0:8174d9ceeca1 | 206 | // Write config register to the ADC |
arve0 | 0:8174d9ceeca1 | 207 | writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); |
arve0 | 0:8174d9ceeca1 | 208 | |
arve0 | 0:8174d9ceeca1 | 209 | // Wait for the conversion to complete |
arve0 | 0:8174d9ceeca1 | 210 | wait_ms(m_conversionDelay); |
arve0 | 0:8174d9ceeca1 | 211 | |
arve0 | 0:8174d9ceeca1 | 212 | // Read the conversion results |
arve0 | 0:8174d9ceeca1 | 213 | uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; |
arve0 | 0:8174d9ceeca1 | 214 | if (m_bitShift == 0) |
arve0 | 0:8174d9ceeca1 | 215 | { |
arve0 | 0:8174d9ceeca1 | 216 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 217 | } |
arve0 | 0:8174d9ceeca1 | 218 | else |
arve0 | 0:8174d9ceeca1 | 219 | { |
arve0 | 0:8174d9ceeca1 | 220 | // Shift 12-bit results right 4 bits for the ADS1015, |
arve0 | 0:8174d9ceeca1 | 221 | // making sure we keep the sign bit intact |
arve0 | 0:8174d9ceeca1 | 222 | if (res > 0x07FF) |
arve0 | 0:8174d9ceeca1 | 223 | { |
arve0 | 0:8174d9ceeca1 | 224 | // negative number - extend the sign to 16th bit |
arve0 | 0:8174d9ceeca1 | 225 | res |= 0xF000; |
arve0 | 0:8174d9ceeca1 | 226 | } |
arve0 | 0:8174d9ceeca1 | 227 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 228 | } |
arve0 | 0:8174d9ceeca1 | 229 | } |
arve0 | 0:8174d9ceeca1 | 230 | |
arve0 | 0:8174d9ceeca1 | 231 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 232 | /*! |
arve0 | 0:8174d9ceeca1 | 233 | @brief Reads the conversion results, measuring the voltage |
arve0 | 0:8174d9ceeca1 | 234 | difference between the P (AIN2) and N (AIN3) input. Generates |
arve0 | 0:8174d9ceeca1 | 235 | a signed value since the difference can be either |
arve0 | 0:8174d9ceeca1 | 236 | positive or negative. |
arve0 | 0:8174d9ceeca1 | 237 | */ |
arve0 | 0:8174d9ceeca1 | 238 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 239 | int16_t Adafruit_ADS1015::readADC_Differential_2_3() { |
arve0 | 0:8174d9ceeca1 | 240 | // Start with default values |
arve0 | 0:8174d9ceeca1 | 241 | uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) |
arve0 | 0:8174d9ceeca1 | 242 | ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) |
arve0 | 0:8174d9ceeca1 | 243 | ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) |
arve0 | 0:8174d9ceeca1 | 244 | ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) |
arve0 | 0:8174d9ceeca1 | 245 | ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) |
arve0 | 0:8174d9ceeca1 | 246 | ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) |
arve0 | 0:8174d9ceeca1 | 247 | |
arve0 | 0:8174d9ceeca1 | 248 | // Set PGA/voltage range |
arve0 | 0:8174d9ceeca1 | 249 | config |= m_gain; |
arve0 | 0:8174d9ceeca1 | 250 | |
arve0 | 0:8174d9ceeca1 | 251 | // Set channels |
arve0 | 0:8174d9ceeca1 | 252 | config |= ADS1015_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N |
arve0 | 0:8174d9ceeca1 | 253 | |
arve0 | 0:8174d9ceeca1 | 254 | // Set 'start single-conversion' bit |
arve0 | 0:8174d9ceeca1 | 255 | config |= ADS1015_REG_CONFIG_OS_SINGLE; |
arve0 | 0:8174d9ceeca1 | 256 | |
arve0 | 0:8174d9ceeca1 | 257 | // Write config register to the ADC |
arve0 | 0:8174d9ceeca1 | 258 | writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); |
arve0 | 0:8174d9ceeca1 | 259 | |
arve0 | 0:8174d9ceeca1 | 260 | // Wait for the conversion to complete |
arve0 | 0:8174d9ceeca1 | 261 | wait_ms(m_conversionDelay); |
arve0 | 0:8174d9ceeca1 | 262 | |
arve0 | 0:8174d9ceeca1 | 263 | // Read the conversion results |
arve0 | 0:8174d9ceeca1 | 264 | uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; |
arve0 | 0:8174d9ceeca1 | 265 | if (m_bitShift == 0) |
arve0 | 0:8174d9ceeca1 | 266 | { |
arve0 | 0:8174d9ceeca1 | 267 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 268 | } |
arve0 | 0:8174d9ceeca1 | 269 | else |
arve0 | 0:8174d9ceeca1 | 270 | { |
arve0 | 0:8174d9ceeca1 | 271 | // Shift 12-bit results right 4 bits for the ADS1015, |
arve0 | 0:8174d9ceeca1 | 272 | // making sure we keep the sign bit intact |
arve0 | 0:8174d9ceeca1 | 273 | if (res > 0x07FF) |
arve0 | 0:8174d9ceeca1 | 274 | { |
arve0 | 0:8174d9ceeca1 | 275 | // negative number - extend the sign to 16th bit |
arve0 | 0:8174d9ceeca1 | 276 | res |= 0xF000; |
arve0 | 0:8174d9ceeca1 | 277 | } |
arve0 | 0:8174d9ceeca1 | 278 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 279 | } |
arve0 | 0:8174d9ceeca1 | 280 | } |
arve0 | 0:8174d9ceeca1 | 281 | |
arve0 | 0:8174d9ceeca1 | 282 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 283 | /*! |
arve0 | 0:8174d9ceeca1 | 284 | @brief Sets up the comparator to operate in basic mode, causing the |
arve0 | 0:8174d9ceeca1 | 285 | ALERT/RDY pin to assert (go from high to low) when the ADC |
arve0 | 0:8174d9ceeca1 | 286 | value exceeds the specified threshold. |
arve0 | 0:8174d9ceeca1 | 287 | |
arve0 | 0:8174d9ceeca1 | 288 | This will also set the ADC in continuous conversion mode. |
arve0 | 0:8174d9ceeca1 | 289 | */ |
arve0 | 0:8174d9ceeca1 | 290 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 291 | void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold) |
arve0 | 0:8174d9ceeca1 | 292 | { |
arve0 | 0:8174d9ceeca1 | 293 | // Start with default values |
arve0 | 0:8174d9ceeca1 | 294 | uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match |
arve0 | 0:8174d9ceeca1 | 295 | ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode |
arve0 | 0:8174d9ceeca1 | 296 | ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) |
arve0 | 0:8174d9ceeca1 | 297 | ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) |
arve0 | 0:8174d9ceeca1 | 298 | ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) |
arve0 | 0:8174d9ceeca1 | 299 | ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode |
arve0 | 0:8174d9ceeca1 | 300 | ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode |
arve0 | 0:8174d9ceeca1 | 301 | |
arve0 | 0:8174d9ceeca1 | 302 | // Set PGA/voltage range |
arve0 | 0:8174d9ceeca1 | 303 | config |= m_gain; |
arve0 | 0:8174d9ceeca1 | 304 | |
arve0 | 0:8174d9ceeca1 | 305 | // Set single-ended input channel |
arve0 | 0:8174d9ceeca1 | 306 | switch (channel) |
arve0 | 0:8174d9ceeca1 | 307 | { |
arve0 | 0:8174d9ceeca1 | 308 | case (0): |
arve0 | 0:8174d9ceeca1 | 309 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_0; |
arve0 | 0:8174d9ceeca1 | 310 | break; |
arve0 | 0:8174d9ceeca1 | 311 | case (1): |
arve0 | 0:8174d9ceeca1 | 312 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_1; |
arve0 | 0:8174d9ceeca1 | 313 | break; |
arve0 | 0:8174d9ceeca1 | 314 | case (2): |
arve0 | 0:8174d9ceeca1 | 315 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_2; |
arve0 | 0:8174d9ceeca1 | 316 | break; |
arve0 | 0:8174d9ceeca1 | 317 | case (3): |
arve0 | 0:8174d9ceeca1 | 318 | config |= ADS1015_REG_CONFIG_MUX_SINGLE_3; |
arve0 | 0:8174d9ceeca1 | 319 | break; |
arve0 | 0:8174d9ceeca1 | 320 | } |
arve0 | 0:8174d9ceeca1 | 321 | |
arve0 | 0:8174d9ceeca1 | 322 | // Set the high threshold register |
arve0 | 0:8174d9ceeca1 | 323 | // Shift 12-bit results left 4 bits for the ADS1015 |
arve0 | 0:8174d9ceeca1 | 324 | writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift); |
arve0 | 0:8174d9ceeca1 | 325 | |
arve0 | 0:8174d9ceeca1 | 326 | // Write config register to the ADC |
arve0 | 0:8174d9ceeca1 | 327 | writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); |
arve0 | 0:8174d9ceeca1 | 328 | } |
arve0 | 0:8174d9ceeca1 | 329 | |
arve0 | 0:8174d9ceeca1 | 330 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 331 | /*! |
arve0 | 0:8174d9ceeca1 | 332 | @brief In order to clear the comparator, we need to read the |
arve0 | 0:8174d9ceeca1 | 333 | conversion results. This function reads the last conversion |
arve0 | 0:8174d9ceeca1 | 334 | results without changing the config value. |
arve0 | 0:8174d9ceeca1 | 335 | */ |
arve0 | 0:8174d9ceeca1 | 336 | /**************************************************************************/ |
arve0 | 0:8174d9ceeca1 | 337 | int16_t Adafruit_ADS1015::getLastConversionResults() |
arve0 | 0:8174d9ceeca1 | 338 | { |
arve0 | 0:8174d9ceeca1 | 339 | // Wait for the conversion to complete |
arve0 | 0:8174d9ceeca1 | 340 | wait_ms(m_conversionDelay); |
arve0 | 0:8174d9ceeca1 | 341 | |
arve0 | 0:8174d9ceeca1 | 342 | // Read the conversion results |
arve0 | 0:8174d9ceeca1 | 343 | uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; |
arve0 | 0:8174d9ceeca1 | 344 | if (m_bitShift == 0) |
arve0 | 0:8174d9ceeca1 | 345 | { |
arve0 | 0:8174d9ceeca1 | 346 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 347 | } |
arve0 | 0:8174d9ceeca1 | 348 | else |
arve0 | 0:8174d9ceeca1 | 349 | { |
arve0 | 0:8174d9ceeca1 | 350 | // Shift 12-bit results right 4 bits for the ADS1015, |
arve0 | 0:8174d9ceeca1 | 351 | // making sure we keep the sign bit intact |
arve0 | 0:8174d9ceeca1 | 352 | if (res > 0x07FF) |
arve0 | 0:8174d9ceeca1 | 353 | { |
arve0 | 0:8174d9ceeca1 | 354 | // negative number - extend the sign to 16th bit |
arve0 | 0:8174d9ceeca1 | 355 | res |= 0xF000; |
arve0 | 0:8174d9ceeca1 | 356 | } |
arve0 | 0:8174d9ceeca1 | 357 | return (int16_t)res; |
arve0 | 0:8174d9ceeca1 | 358 | } |
arve0 | 0:8174d9ceeca1 | 359 | } |