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
Revision 2:976073ea60df, committed 2014-07-22
- Comitter:
- Sambo007
- Date:
- Tue Jul 22 06:04:13 2014 +0000
- Parent:
- 1:a628fdaed351
- Commit message:
- 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;
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ADS1x15.cpp Tue Jul 22 06:04:13 2014 +0000 @@ -0,0 +1,306 @@ +/**************************************************************************/ +/*! + @file ADS1x15.cpp + @author K.Townsend (Adafruit Industries) + @license BSD (see LICENSE.txt) + + Ported to mbed by Arve Seljebu - arve0.github.io + + Driver for the ADS1015/ADS1115 ADC + + This is a library for the Adafruit MPL115A2 breakout + ----> https://www.adafruit.com/products/1083 + + Adafruit invests time and resources providing this open source code, + please support Adafruit and open-source hardware by purchasing + products from Adafruit! + + @section HISTORY + + v1.0 - First release + v1.1 - Added ADS1115 support - W. Earl + v1.1.1 - Ported to mbed - Arve Seljebu + v1.2 - Fixed error in readADC_SingleEnded() sign bit - Sam Berjawi + v1.3 - Added ADS1115_REG_CONFIG_DR & m_dataRate - Sam W Berjawi Jul 21. 2014 + - Corrected m_conversionDelay + - Now there is readADC() that returns counts and readADC_V() that returns voltage +*/ +/**************************************************************************/ + +#include "ADS1x15.h" + +/**************************************************************************/ +/*! + @brief Writes 16-bits to the specified destination register +*/ +/**************************************************************************/ +void ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value) { + char cmd[3]; + cmd[0] = (char)reg; + cmd[1] = (char)(value>>8); + cmd[2] = (char)(value & 0xFF); + m_i2c->write(i2cAddress, cmd, 3); +} + +/**************************************************************************/ +/*! + @brief Reads 16-bits from the specified register +*/ +/**************************************************************************/ +uint16_t ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg) { + char data[2]; + data[0] = reg; // temporary use this to send address to conversion register + m_i2c->write(i2cAddress, data, 1); + m_i2c->read(i2cAddress, data, 2); + return (data[0] << 8 | data [1]); +} + +/**************************************************************************/ +/*! + @brief Instantiates a new ADS1015 class w/appropriate properties +*/ +/**************************************************************************/ +ADS1015::ADS1015(I2C* i2c, uint8_t i2cAddress) +{ + // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h + m_i2cAddress = i2cAddress << 1; + m_bitShift = 4; + m_i2c = i2c; +} + +/**************************************************************************/ +/*! + @brief Instantiates a new ADS1115 class w/appropriate properties +*/ +/**************************************************************************/ +ADS1115::ADS1115(I2C* i2c, uint8_t i2cAddress) +{ + // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h + m_i2cAddress = i2cAddress << 1; + m_bitShift = 0; + m_i2c = i2c; +} + +/**************************************************************************/ +/*! + @brief Reads the A2D conversion result, measuring depending on chan parameter either + the single chan voltage or the differential voltage between the P (AIN_i) and N (AIN_j) inputs. + Generates a signed value since the difference can be either positive or negative. + + The +/-6.144V and +/-4.096V settings express the full-scale range of the ADC scaling. + In no event should more than VDD + 0.3V be applied to this device + + @return Count +*/ +/**************************************************************************/ +int16_t ADS1015::readADC(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate) +{ + // Prepare Config Register + uint16_t config = ADS1015_REG_CONFIG_OS_SINGLE | // Begin a single conversion (when in power-down mode) + ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) + ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) + ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) + ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) + ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) + + // Set channel(s) + config |= chan; + + // Set PGA/voltage range + config |= voltageRange; + + // Set Data rate + config |= dataRate; + + // Write config register to the ADC + writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); + + // TODO: Modify to alternatively use the RDY (EOC) pin instead of waiting. Maybe also use interrupt and continuous mode + + if (m_bitShift == 4) // ADS1015 + switch (dataRate) { + case ADS1015_DR_128SPS: + m_conversionDelay = 1.0 / 128; + break; + case ADS1015_DR_250SPS: + m_conversionDelay = 1.0 / 250; + break; + case ADS1015_DR_490SPS: + m_conversionDelay = 1.0 / 490; + break; + case ADS1015_DR_920SPS: + m_conversionDelay = 1.0 / 920; + break; + case ADS1015_DR_1600SPS: + m_conversionDelay = 1.0 / 1600; + break; + case ADS1015_DR_2400SPS: + m_conversionDelay = 1.0 / 2400; + break; + case ADS1015_DR_3300SPS: + m_conversionDelay = 1.0 / 3300; + break; + } + else // ADS1115 + switch (dataRate) { + case ADS1115_DR_8SPS: + m_conversionDelay = 1.0 / 8; + break; + case ADS1115_DR_16SPS: + m_conversionDelay = 1.0 / 16; + break; + case ADS1115_DR_32SPS: + m_conversionDelay = 1.0 / 32; + break; + case ADS1115_DR_64SPS: + m_conversionDelay = 1.0 / 64; + break; + case ADS1115_DR_128SPS: + m_conversionDelay = 1.0 / 128; + break; + case ADS1115_DR_250SPS: + m_conversionDelay = 1.0 / 250; + break; + case ADS1115_DR_475SPS: + m_conversionDelay = 1.0 / 475; + break; + case ADS1115_DR_860SPS: + m_conversionDelay = 1.0 / 860; + break; + } + + // Wait for the conversion to complete + wait(m_conversionDelay); + + // Read the conversion results + uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; + if (m_bitShift == 0) + { + return (int16_t)res; + } + else + { + // Shift 12-bit results right 4 bits for the ADS1015, + // making sure we keep the sign bit intact + if (res > 0x07FF) + { + // negative number - extend the sign to 16th bit + res |= 0xF000; + } + return (int16_t)res; + } +} + +/**************************************************************************/ +/*! + @brief Reads the A2D conversion result, measuring depending on chan parameter either + the single chan voltage or the differential voltage between the P (AIN_i) and N (AIN_j) inputs. + Generates a signed value since the difference can be either positive or negative. + + The +/-6.144V and +/-4.096V settings express the full-scale range of the ADC scaling. + In no event should more than VDD + 0.3V be applied to this device + + @return Voltage +*/ +/**************************************************************************/ +float ADS1015::readADC_V(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate) +{ +float bit_V = 0.; + + // ADS1015 ADS1115 + // +/-6.144V range = Gain 2/3 1-bit = 3mV 0.1875mV + // +/-4.096V range = Gain 1 1-bit = 2mV 0.125mV + // +/-2.048V range = Gain 2 1-bit = 1mV 0.0625mV + // +/-1.024V range = Gain 4 1-bit = 0.5mV 0.03125mV + // +/-0.512V range = Gain 8 1-bit = 0.25mV 0.015625mV + // +/-0.256V range = Gain 16 1-bit = 0.125mV 0.0078125mV + + switch (voltageRange) { + case VR_p_m_6_144V: + bit_V = 3.0e-3f * powf(2, -4 + m_bitShift); + break; + case VR_p_m_4_096V: + bit_V = 2.0e-3f * powf(2, -4 + m_bitShift); + break; + case VR_p_m_2_048V: + bit_V = 1.0e-3f * powf(2, -4 + m_bitShift); + break; + case VR_p_m_1_024V: + bit_V = 0.5e-3f * powf(2, -4 + m_bitShift); + break; + case VR_p_m_0_512V: + bit_V = 0.25e-3f * powf(2, -4 + m_bitShift); + break; + case VR_p_m_0_256V: + bit_V = 0.125e-3f * powf(2, -4 + m_bitShift); + break; + } + + return (readADC(chan, voltageRange, dataRate) * bit_V); +} + +/**************************************************************************/ +/*! + @brief Sets up the comparator to operate in basic mode, causing the + ALERT/RDY pin to assert (go from high to low) when the ADC + value exceeds the specified threshold. + + This will also set the ADC in continuous conversion mode. +*/ +/**************************************************************************/ +void ADS1015::startComparator_SingleEnded(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate, int16_t threshold) +{ + // Prepare Config Register + uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match + ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode + ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) + ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) + ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) + + // Set channel(s) + config |= chan; + + // Set PGA/voltage range + config |= voltageRange; + + // Set Data rate + config |= dataRate; + + // Set the high threshold register + // Shift 12-bit results left 4 bits for the ADS1015 + writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift); + + // Write config register to the ADC + writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); +} + +/**************************************************************************/ +/*! + @brief In order to clear the comparator, we need to read the + conversion results. This function reads the last conversion + results without changing the config value. +*/ +/**************************************************************************/ +int16_t ADS1015::getLastConversionResults() +{ + // Wait for the conversion to complete + wait_ms(m_conversionDelay); + + // Read the conversion results + uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; + if (m_bitShift == 0) + { + return (int16_t)res; + } + else + { + // Shift 12-bit results right 4 bits for the ADS1015, + // making sure we keep the sign bit intact + if (res > 0x07FF) + { + // negative number - extend the sign to 16th bit + res |= 0xF000; + } + return (int16_t)res; + } +}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ADS1x15.h Tue Jul 22 06:04:13 2014 +0000 @@ -0,0 +1,200 @@ +/**************************************************************************/ +/*! + @file ADS1x15.h + @author K. Townsend (Adafruit Industries) + @license BSD (see LICENSE.txt) + + Ported to mbed by Arve Seljebu - arve0.github.io + + ADS1015 12-bit I2C ADC+PGA and ADS1115 16-bit I2C ADC+PGA + + This is a library for the Adafruit ADS1015 and ADS1015 breakout boards + ----> https://www.adafruit.com/products/1083 + + Adafruit invests time and resources providing this open source code, + please support Adafruit and open-source hardware by purchasing + products from Adafruit! + + @section HISTORY + + v1.0 - First release + v1.1 - Added ADS1115 support - W. Earl + v1.1.1 - Ported to mbed - Arve Seljebu + v1.2 - Fixed error in readADC_SingleEnded() sign bit - Sam W Berjawi + v1.3 - Added ADS1115_REG_CONFIG_DR & ads1015_DR_t - Sam W Berjawi Jul 21. 2014 + - Corrected m_conversionDelay + - Now there is readADC() that returns counts and readADC_V() that returns voltage +*/ +/**************************************************************************/ + +#ifndef ADS1015_H +#define ADS1015_H + +#include <mbed.h> + +/*========================================================================= + I2C ADDRESS/BITS + -----------------------------------------------------------------------*/ + #define ADS1015_ADDRESS (0x48) // 0100 1000 (ADDR = GND) +/*=========================================================================*/ + +/*========================================================================= + CONVERSION DELAY (in mS) + -----------------------------------------------------------------------*/ +// #define ADS1015_CONVERSIONDELAY (1) +// #define ADS1115_CONVERSIONDELAY (8) +/*=========================================================================*/ + +/*========================================================================= + POINTER REGISTER + -----------------------------------------------------------------------*/ + #define ADS1015_REG_POINTER_MASK (0x03) + #define ADS1015_REG_POINTER_CONVERT (0x00) + #define ADS1015_REG_POINTER_CONFIG (0x01) + #define ADS1015_REG_POINTER_LOWTHRESH (0x02) + #define ADS1015_REG_POINTER_HITHRESH (0x03) +/*=========================================================================*/ + +/*========================================================================= + CONFIG REGISTER + -----------------------------------------------------------------------*/ + #define ADS1015_REG_CONFIG_OS_MASK (0x8000) + #define ADS1015_REG_CONFIG_OS_SINGLE (0x8000) // Write: Set to start a single-conversion + #define ADS1015_REG_CONFIG_OS_BUSY (0x0000) // Read: Bit = 0 when conversion is in progress + #define ADS1015_REG_CONFIG_OS_NOTBUSY (0x8000) // Read: Bit = 1 when device is not performing a conversion + +// #define ADS1015_REG_CONFIG_MUX_MASK (0x7000) +// #define ADS1015_REG_CONFIG_MUX_DIFF_0_1 (0x0000) // Differential P = AIN0, N = AIN1 (default) +// #define ADS1015_REG_CONFIG_MUX_DIFF_0_3 (0x1000) // Differential P = AIN0, N = AIN3 +// #define ADS1015_REG_CONFIG_MUX_DIFF_1_3 (0x2000) // Differential P = AIN1, N = AIN3 +// #define ADS1015_REG_CONFIG_MUX_DIFF_2_3 (0x3000) // Differential P = AIN2, N = AIN3 +// #define ADS1015_REG_CONFIG_MUX_SINGLE_0 (0x4000) // Single-ended AIN0 +// #define ADS1015_REG_CONFIG_MUX_SINGLE_1 (0x5000) // Single-ended AIN1 +// #define ADS1015_REG_CONFIG_MUX_SINGLE_2 (0x6000) // Single-ended AIN2 +// #define ADS1015_REG_CONFIG_MUX_SINGLE_3 (0x7000) // Single-ended AIN3 + +// #define ADS1015_REG_CONFIG_PGA_MASK (0x0E00) +// #define ADS1015_REG_CONFIG_PGA_6_144V (0x0000) // +/-6.144V range = Gain 2/3 ADS1015: 1-bit = 3mV ADS1115: 0.1875mV +// #define ADS1015_REG_CONFIG_PGA_4_096V (0x0200) // +/-4.096V range = Gain 1 ADS1015: 1-bit = 2mV ADS1115: 0.125mV +// #define ADS1015_REG_CONFIG_PGA_2_048V (0x0400) // +/-2.048V range = Gain 2 (default) ADS1015: 1-bit = 1mV ADS1115: 0.0625mV +// #define ADS1015_REG_CONFIG_PGA_1_024V (0x0600) // +/-1.024V range = Gain 4 ADS1015: 1-bit = 0.5mV ADS1115: 0.03125mV +// #define ADS1015_REG_CONFIG_PGA_0_512V (0x0800) // +/-0.512V range = Gain 8 ADS1015: 1-bit = 0.25mV ADS1115: 0.015625mV +// #define ADS1015_REG_CONFIG_PGA_0_256V (0x0A00) // +/-0.256V range = Gain 16 ADS1015: 1-bit = 0.125mV ADS1115: 0.0078125mV + + #define ADS1015_REG_CONFIG_MODE_MASK (0x0100) + #define ADS1015_REG_CONFIG_MODE_CONTIN (0x0000) // Continuous conversion mode + #define ADS1015_REG_CONFIG_MODE_SINGLE (0x0100) // Power-down single-shot mode (default) + +// #define ADS1015_REG_CONFIG_DR_MASK (0x00E0) +// #define ADS1015_REG_CONFIG_DR_128SPS (0x0000) // 128 SPS +// #define ADS1015_REG_CONFIG_DR_250SPS (0x0020) // 250 SPS +// #define ADS1015_REG_CONFIG_DR_490SPS (0x0040) // 490 SPS +// #define ADS1015_REG_CONFIG_DR_920SPS (0x0060) // 920 SPS +// #define ADS1015_REG_CONFIG_DR_1600SPS (0x0080) // 1600 SPS (default) +// #define ADS1015_REG_CONFIG_DR_2400SPS (0x00A0) // 2400 SPS +// #define ADS1015_REG_CONFIG_DR_3300SPS (0x00C0) // 3300 SPS +// +// #define ADS1115_REG_CONFIG_DR_MASK (0x00E0) +// #define ADS1115_REG_CONFIG_DR_8SPS (0x0000) // 8 SPS +// #define ADS1115_REG_CONFIG_DR_16SPS (0x0020) // 16 SPS +// #define ADS1115_REG_CONFIG_DR_32SPS (0x0040) // 32 SPS +// #define ADS1115_REG_CONFIG_DR_64SPS (0x0060) // 64 SPS +// #define ADS1115_REG_CONFIG_DR_128SPS (0x0080) // 128 SPS (default) +// #define ADS1115_REG_CONFIG_DR_250SPS (0x00A0) // 250 SPS +// #define ADS1115_REG_CONFIG_DR_475SPS (0x00C0) // 475 SPS +// #define ADS1115_REG_CONFIG_DR_860SPS (0x00E0) // 860 SPS + + #define ADS1015_REG_CONFIG_CMODE_MASK (0x0010) + #define ADS1015_REG_CONFIG_CMODE_TRAD (0x0000) // Traditional comparator with hysteresis (default) + #define ADS1015_REG_CONFIG_CMODE_WINDOW (0x0010) // Window comparator + + #define ADS1015_REG_CONFIG_CPOL_MASK (0x0008) + #define ADS1015_REG_CONFIG_CPOL_ACTVLOW (0x0000) // ALERT/RDY pin is low when active (default) + #define ADS1015_REG_CONFIG_CPOL_ACTVHI (0x0008) // ALERT/RDY pin is high when active + + #define ADS1015_REG_CONFIG_CLAT_MASK (0x0004) // Determines if ALERT/RDY pin latches once asserted + #define ADS1015_REG_CONFIG_CLAT_NONLAT (0x0000) // Non-latching comparator (default) + #define ADS1015_REG_CONFIG_CLAT_LATCH (0x0004) // Latching comparator + + #define ADS1015_REG_CONFIG_CQUE_MASK (0x0003) + #define ADS1015_REG_CONFIG_CQUE_1CONV (0x0000) // Assert ALERT/RDY after one conversions + #define ADS1015_REG_CONFIG_CQUE_2CONV (0x0001) // Assert ALERT/RDY after two conversions + #define ADS1015_REG_CONFIG_CQUE_4CONV (0x0002) // Assert ALERT/RDY after four conversions + #define ADS1015_REG_CONFIG_CQUE_NONE (0x0003) // Disable the comparator and put ALERT/RDY in high state (default) +/*=========================================================================*/ + +typedef enum +{ + chan_0_1 = 0x0000, // Differential P = AIN0, N = AIN1 (default) + chan_0_3 = 0x1000, // Differential P = AIN0, N = AIN3 + chan_1_3 = 0x2000, // Differential P = AIN1, N = AIN3 + chan_2_3 = 0x3000, // Differential P = AIN2, N = AIN3 + chan_0 = 0x4000, // Single-ended AIN0 + chan_1 = 0x5000, // Single-ended AIN1 + chan_2 = 0x6000, // Single-ended AIN2 + chan_3 = 0x7000 // Single-ended AIN3 +} chan_t; + +// The +/-6.144V and +/-4.096V settings express the full-scale range of the ADC scaling. +// In no event should more than VDD + 0.3V be applied to this device +typedef enum +{ // ADS1015 ADS1115 + VR_p_m_6_144V = 0x0000, // +/-6.144V range = Gain 2/3 1-bit = 3mV 0.1875mV + VR_p_m_4_096V = 0x0200, // +/-4.096V range = Gain 1 1-bit = 2mV 0.125mV + VR_p_m_2_048V = 0x0400, // +/-2.048V range = Gain 2 1-bit = 1mV 0.0625mV + VR_p_m_1_024V = 0x0600, // +/-1.024V range = Gain 4 1-bit = 0.5mV 0.03125mV + VR_p_m_0_512V = 0x0800, // +/-0.512V range = Gain 8 1-bit = 0.25mV 0.015625mV + VR_p_m_0_256V = 0x0A00 // +/-0.256V range = Gain 16 1-bit = 0.125mV 0.0078125mV +} adsVR_t; // VR: Voltage Range + +typedef enum +{ + ADS1015_DR_128SPS = 0x0000, // 128 SPS + ADS1015_DR_250SPS = 0x0020, // 250 SPS + ADS1015_DR_490SPS = 0x0040, // 490 SPS + ADS1015_DR_920SPS = 0x0060, // 920 SPS + ADS1015_DR_1600SPS = 0x0080, // 1600 SPS + ADS1015_DR_2400SPS = 0x00A0, // 2400 SPS + ADS1015_DR_3300SPS = 0x00C0, // 3300 SPS + + ADS1115_DR_8SPS = 0x0000, // 8 SPS + ADS1115_DR_16SPS = 0x0020, // 16 SPS + ADS1115_DR_32SPS = 0x0040, // 32 SPS + ADS1115_DR_64SPS = 0x0060, // 64 SPS + ADS1115_DR_128SPS = 0x0080, // 128 SPS + ADS1115_DR_250SPS = 0x00A0, // 250 SPS + ADS1115_DR_475SPS = 0x00C0, // 475 SPS + ADS1115_DR_860SPS = 0x00E0 // 860 SPS +} adsDR_t; // DR: Data Rate + + +class ADS1015 +{ +protected: + // Instance-specific properties + uint8_t m_i2cAddress; +// ads1015_DR_t m_dataRate; + float m_conversionDelay; + uint8_t m_bitShift; + I2C* m_i2c; + + public: + ADS1015(I2C* i2c = 0, uint8_t i2cAddress = ADS1015_ADDRESS); // set i2c ptr = 0 to allow ADS1115 to use this as default constructor + int16_t readADC(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate); + float readADC_V(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate); + void startComparator_SingleEnded(chan_t chan, adsVR_t voltageRange, adsDR_t dataRate, int16_t threshold); + int16_t getLastConversionResults(); + + private: + uint16_t readRegister(uint8_t i2cAddress, uint8_t reg); + void writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value); +}; + +// Derive from ADS1015 & override construction to set properties +class ADS1115 : public ADS1015 +{ + public: + ADS1115(I2C* i2c, uint8_t i2cAddress = ADS1015_ADDRESS); +}; + +#endif
--- a/Adafruit_ADS1015.cpp Wed May 21 13:12:24 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,359 +0,0 @@ -/**************************************************************************/ -/*! - @file Adafruit_ADS1015.cpp - @author K.Townsend (Adafruit Industries) - @license BSD (see LICENSE.txt) - - Ported to mbed by Arve Seljebu - arve0.github.io - - Driver for the ADS1015/ADS1115 ADC - - This is a library for the Adafruit MPL115A2 breakout - ----> https://www.adafruit.com/products/1083 - - Adafruit invests time and resources providing this open source code, - please support Adafruit and open-source hardware by purchasing - products from Adafruit! - - @section HISTORY - - v1.0 - First release - v1.1 - Added ADS1115 support - W. Earl - v1.1.1 - Ported to mbed - Arve Seljebu - v1.2 - Fixed error in readADC_SingleEnded() sign bit - Sam Berjawi -*/ -/**************************************************************************/ - -#include <mbed.h> -#include "Adafruit_ADS1015.h" - -/**************************************************************************/ -/*! - @brief Writes 16-bits to the specified destination register -*/ -/**************************************************************************/ -void Adafruit_ADS1015::writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value) { - char cmd[3]; - cmd[0] = (char)reg; - cmd[1] = (char)(value>>8); - cmd[2] = (char)(value & 0xFF); - m_i2c->write(i2cAddress, cmd, 3); -} - -/**************************************************************************/ -/*! - @brief Reads 16-bits from the specified register -*/ -/**************************************************************************/ -uint16_t Adafruit_ADS1015::readRegister(uint8_t i2cAddress, uint8_t reg) { - char data[2]; - data[0] = reg; // temporary use this to send address to conversion register - m_i2c->write(i2cAddress, data, 1); - m_i2c->read(i2cAddress, data, 2); - return (data[0] << 8 | data [1]); -} - -/**************************************************************************/ -/*! - @brief Instantiates a new ADS1015 class w/appropriate properties -*/ -/**************************************************************************/ -Adafruit_ADS1015::Adafruit_ADS1015(I2C* i2c, uint8_t i2cAddress) -{ - // shift 7 bit address 1 left: read expects 8 bit address, see I2C.h - m_i2cAddress = i2cAddress << 1; - m_conversionDelay = ADS1015_CONVERSIONDELAY; - m_bitShift = 4; - m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */ - m_i2c = i2c; -} - -/**************************************************************************/ -/*! - @brief Instantiates a new ADS1115 class w/appropriate properties -*/ -/**************************************************************************/ -Adafruit_ADS1115::Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress) -{ - // shift 7 bit address 1 left: read expects 8 bit address, see mbed's I2C.h - m_i2cAddress = i2cAddress << 1; - m_conversionDelay = ADS1115_CONVERSIONDELAY; - m_bitShift = 0; - m_gain = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */ - m_i2c = i2c; -} - -/**************************************************************************/ -/*! - @brief Sets the gain and input voltage range -*/ -/**************************************************************************/ -void Adafruit_ADS1015::setGain(adsGain_t gain) -{ - m_gain = gain; -} - -/**************************************************************************/ -/*! - @brief Gets a gain and input voltage range -*/ -/**************************************************************************/ -adsGain_t Adafruit_ADS1015::getGain() -{ - return m_gain; -} - -/**************************************************************************/ -/*! - @brief Gets a single-ended ADC reading from the specified channel -*/ -/**************************************************************************/ -//uint16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel) { SWB -int16_t Adafruit_ADS1015::readADC_SingleEnded(uint8_t channel) { - if (channel > 3) - { - return 0; - } - - // Start with default values - uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) - ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) - ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) - ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) - ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) - ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) - - // Set PGA/voltage range - config |= m_gain; - - // Set single-ended input channel - switch (channel) - { - case (0): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_0; - break; - case (1): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_1; - break; - case (2): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_2; - break; - case (3): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_3; - break; - } - - // Set 'start single-conversion' bit - config |= ADS1015_REG_CONFIG_OS_SINGLE; - - // Write config register to the ADC - writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); - - // Wait for the conversion to complete - wait_ms(m_conversionDelay); - - // Read the conversion results - // Shift 12-bit results right 4 bits for the ADS1015 - //return readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; SWB - - // SWB - // Shift 12-bit results right 4 bits for the ADS1015 - uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; - - if (m_bitShift == 0) - { - return (int16_t)res; - } - else - { - // Shift 12-bit results right 4 bits for the ADS1015, - // making sure we keep the sign bit intact - if (res > 0x07FF) - { - // negative number - extend the sign to 16th bit - res |= 0xF000; - } - return (int16_t)res; - } -} - -/**************************************************************************/ -/*! - @brief Reads the conversion results, measuring the voltage - difference between the P (AIN0) and N (AIN1) input. Generates - a signed value since the difference can be either - positive or negative. -*/ -/**************************************************************************/ -int16_t Adafruit_ADS1015::readADC_Differential_0_1() { - // Start with default values - uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) - ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) - ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) - ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) - ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) - ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) - - // Set PGA/voltage range - config |= m_gain; - - // Set channels - config |= ADS1015_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N - - // Set 'start single-conversion' bit - config |= ADS1015_REG_CONFIG_OS_SINGLE; - - // Write config register to the ADC - writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); - - // Wait for the conversion to complete - wait_ms(m_conversionDelay); - - // Read the conversion results - uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; - if (m_bitShift == 0) - { - return (int16_t)res; - } - else - { - // Shift 12-bit results right 4 bits for the ADS1015, - // making sure we keep the sign bit intact - if (res > 0x07FF) - { - // negative number - extend the sign to 16th bit - res |= 0xF000; - } - return (int16_t)res; - } -} - -/**************************************************************************/ -/*! - @brief Reads the conversion results, measuring the voltage - difference between the P (AIN2) and N (AIN3) input. Generates - a signed value since the difference can be either - positive or negative. -*/ -/**************************************************************************/ -int16_t Adafruit_ADS1015::readADC_Differential_2_3() { - // Start with default values - uint16_t config = ADS1015_REG_CONFIG_CQUE_NONE | // Disable the comparator (default val) - ADS1015_REG_CONFIG_CLAT_NONLAT | // Non-latching (default val) - ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) - ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) - ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) - ADS1015_REG_CONFIG_MODE_SINGLE; // Single-shot mode (default) - - // Set PGA/voltage range - config |= m_gain; - - // Set channels - config |= ADS1015_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N - - // Set 'start single-conversion' bit - config |= ADS1015_REG_CONFIG_OS_SINGLE; - - // Write config register to the ADC - writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); - - // Wait for the conversion to complete - wait_ms(m_conversionDelay); - - // Read the conversion results - uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; - if (m_bitShift == 0) - { - return (int16_t)res; - } - else - { - // Shift 12-bit results right 4 bits for the ADS1015, - // making sure we keep the sign bit intact - if (res > 0x07FF) - { - // negative number - extend the sign to 16th bit - res |= 0xF000; - } - return (int16_t)res; - } -} - -/**************************************************************************/ -/*! - @brief Sets up the comparator to operate in basic mode, causing the - ALERT/RDY pin to assert (go from high to low) when the ADC - value exceeds the specified threshold. - - This will also set the ADC in continuous conversion mode. -*/ -/**************************************************************************/ -void Adafruit_ADS1015::startComparator_SingleEnded(uint8_t channel, int16_t threshold) -{ - // Start with default values - uint16_t config = ADS1015_REG_CONFIG_CQUE_1CONV | // Comparator enabled and asserts on 1 match - ADS1015_REG_CONFIG_CLAT_LATCH | // Latching mode - ADS1015_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low (default val) - ADS1015_REG_CONFIG_CMODE_TRAD | // Traditional comparator (default val) - ADS1015_REG_CONFIG_DR_1600SPS | // 1600 samples per second (default) - ADS1015_REG_CONFIG_MODE_CONTIN | // Continuous conversion mode - ADS1015_REG_CONFIG_MODE_CONTIN; // Continuous conversion mode - - // Set PGA/voltage range - config |= m_gain; - - // Set single-ended input channel - switch (channel) - { - case (0): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_0; - break; - case (1): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_1; - break; - case (2): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_2; - break; - case (3): - config |= ADS1015_REG_CONFIG_MUX_SINGLE_3; - break; - } - - // Set the high threshold register - // Shift 12-bit results left 4 bits for the ADS1015 - writeRegister(m_i2cAddress, ADS1015_REG_POINTER_HITHRESH, threshold << m_bitShift); - - // Write config register to the ADC - writeRegister(m_i2cAddress, ADS1015_REG_POINTER_CONFIG, config); -} - -/**************************************************************************/ -/*! - @brief In order to clear the comparator, we need to read the - conversion results. This function reads the last conversion - results without changing the config value. -*/ -/**************************************************************************/ -int16_t Adafruit_ADS1015::getLastConversionResults() -{ - // Wait for the conversion to complete - wait_ms(m_conversionDelay); - - // Read the conversion results - uint16_t res = readRegister(m_i2cAddress, ADS1015_REG_POINTER_CONVERT) >> m_bitShift; - if (m_bitShift == 0) - { - return (int16_t)res; - } - else - { - // Shift 12-bit results right 4 bits for the ADS1015, - // making sure we keep the sign bit intact - if (res > 0x07FF) - { - // negative number - extend the sign to 16th bit - res |= 0xF000; - } - return (int16_t)res; - } -}
--- a/Adafruit_ADS1015.h Wed May 21 13:12:24 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,151 +0,0 @@ -/**************************************************************************/ -/*! - @file Adafruit_ADS1015.h - @author K. Townsend (Adafruit Industries) - @license BSD (see LICENSE.txt) - - Ported to mbed by Arve Seljebu - arve0.github.io - - This is a library for the Adafruit ADS1015 breakout board - ----> https://www.adafruit.com/products/1083 - - Adafruit invests time and resources providing this open source code, - please support Adafruit and open-source hardware by purchasing - products from Adafruit! - - @section HISTORY - - v1.0 - First release - v1.1 - Added ADS1115 support - W. Earl - v1.1.1 - Ported to mbed - Arve Seljebu - v1.2 - Fixed error in readADC_SingleEnded() sign bit - Sam Berjawi -*/ -/**************************************************************************/ - -#include <mbed.h> - -/*========================================================================= - I2C ADDRESS/BITS - -----------------------------------------------------------------------*/ - #define ADS1015_ADDRESS (0x48) // 1001 000 (ADDR = GND) -/*=========================================================================*/ - -/*========================================================================= - CONVERSION DELAY (in mS) - -----------------------------------------------------------------------*/ - #define ADS1015_CONVERSIONDELAY (1) - #define ADS1115_CONVERSIONDELAY (8) -/*=========================================================================*/ - -/*========================================================================= - POINTER REGISTER - -----------------------------------------------------------------------*/ - #define ADS1015_REG_POINTER_MASK (0x03) - #define ADS1015_REG_POINTER_CONVERT (0x00) - #define ADS1015_REG_POINTER_CONFIG (0x01) - #define ADS1015_REG_POINTER_LOWTHRESH (0x02) - #define ADS1015_REG_POINTER_HITHRESH (0x03) -/*=========================================================================*/ - -/*========================================================================= - CONFIG REGISTER - -----------------------------------------------------------------------*/ - #define ADS1015_REG_CONFIG_OS_MASK (0x8000) - #define ADS1015_REG_CONFIG_OS_SINGLE (0x8000) // Write: Set to start a single-conversion - #define ADS1015_REG_CONFIG_OS_BUSY (0x0000) // Read: Bit = 0 when conversion is in progress - #define ADS1015_REG_CONFIG_OS_NOTBUSY (0x8000) // Read: Bit = 1 when device is not performing a conversion - - #define ADS1015_REG_CONFIG_MUX_MASK (0x7000) - #define ADS1015_REG_CONFIG_MUX_DIFF_0_1 (0x0000) // Differential P = AIN0, N = AIN1 (default) - #define ADS1015_REG_CONFIG_MUX_DIFF_0_3 (0x1000) // Differential P = AIN0, N = AIN3 - #define ADS1015_REG_CONFIG_MUX_DIFF_1_3 (0x2000) // Differential P = AIN1, N = AIN3 - #define ADS1015_REG_CONFIG_MUX_DIFF_2_3 (0x3000) // Differential P = AIN2, N = AIN3 - #define ADS1015_REG_CONFIG_MUX_SINGLE_0 (0x4000) // Single-ended AIN0 - #define ADS1015_REG_CONFIG_MUX_SINGLE_1 (0x5000) // Single-ended AIN1 - #define ADS1015_REG_CONFIG_MUX_SINGLE_2 (0x6000) // Single-ended AIN2 - #define ADS1015_REG_CONFIG_MUX_SINGLE_3 (0x7000) // Single-ended AIN3 - - #define ADS1015_REG_CONFIG_PGA_MASK (0x0E00) - #define ADS1015_REG_CONFIG_PGA_6_144V (0x0000) // +/-6.144V range = Gain 2/3 - #define ADS1015_REG_CONFIG_PGA_4_096V (0x0200) // +/-4.096V range = Gain 1 - #define ADS1015_REG_CONFIG_PGA_2_048V (0x0400) // +/-2.048V range = Gain 2 (default) - #define ADS1015_REG_CONFIG_PGA_1_024V (0x0600) // +/-1.024V range = Gain 4 - #define ADS1015_REG_CONFIG_PGA_0_512V (0x0800) // +/-0.512V range = Gain 8 - #define ADS1015_REG_CONFIG_PGA_0_256V (0x0A00) // +/-0.256V range = Gain 16 - - #define ADS1015_REG_CONFIG_MODE_MASK (0x0100) - #define ADS1015_REG_CONFIG_MODE_CONTIN (0x0000) // Continuous conversion mode - #define ADS1015_REG_CONFIG_MODE_SINGLE (0x0100) // Power-down single-shot mode (default) - - #define ADS1015_REG_CONFIG_DR_MASK (0x00E0) - #define ADS1015_REG_CONFIG_DR_128SPS (0x0000) // 128 samples per second - #define ADS1015_REG_CONFIG_DR_250SPS (0x0020) // 250 samples per second - #define ADS1015_REG_CONFIG_DR_490SPS (0x0040) // 490 samples per second - #define ADS1015_REG_CONFIG_DR_920SPS (0x0060) // 920 samples per second - #define ADS1015_REG_CONFIG_DR_1600SPS (0x0080) // 1600 samples per second (default) - #define ADS1015_REG_CONFIG_DR_2400SPS (0x00A0) // 2400 samples per second - #define ADS1015_REG_CONFIG_DR_3300SPS (0x00C0) // 3300 samples per second - - #define ADS1015_REG_CONFIG_CMODE_MASK (0x0010) - #define ADS1015_REG_CONFIG_CMODE_TRAD (0x0000) // Traditional comparator with hysteresis (default) - #define ADS1015_REG_CONFIG_CMODE_WINDOW (0x0010) // Window comparator - - #define ADS1015_REG_CONFIG_CPOL_MASK (0x0008) - #define ADS1015_REG_CONFIG_CPOL_ACTVLOW (0x0000) // ALERT/RDY pin is low when active (default) - #define ADS1015_REG_CONFIG_CPOL_ACTVHI (0x0008) // ALERT/RDY pin is high when active - - #define ADS1015_REG_CONFIG_CLAT_MASK (0x0004) // Determines if ALERT/RDY pin latches once asserted - #define ADS1015_REG_CONFIG_CLAT_NONLAT (0x0000) // Non-latching comparator (default) - #define ADS1015_REG_CONFIG_CLAT_LATCH (0x0004) // Latching comparator - - #define ADS1015_REG_CONFIG_CQUE_MASK (0x0003) - #define ADS1015_REG_CONFIG_CQUE_1CONV (0x0000) // Assert ALERT/RDY after one conversions - #define ADS1015_REG_CONFIG_CQUE_2CONV (0x0001) // Assert ALERT/RDY after two conversions - #define ADS1015_REG_CONFIG_CQUE_4CONV (0x0002) // Assert ALERT/RDY after four conversions - #define ADS1015_REG_CONFIG_CQUE_NONE (0x0003) // Disable the comparator and put ALERT/RDY in high state (default) -/*=========================================================================*/ - -typedef enum -{ - GAIN_TWOTHIRDS = ADS1015_REG_CONFIG_PGA_6_144V, - GAIN_ONE = ADS1015_REG_CONFIG_PGA_4_096V, - GAIN_TWO = ADS1015_REG_CONFIG_PGA_2_048V, - GAIN_FOUR = ADS1015_REG_CONFIG_PGA_1_024V, - GAIN_EIGHT = ADS1015_REG_CONFIG_PGA_0_512V, - GAIN_SIXTEEN = ADS1015_REG_CONFIG_PGA_0_256V -} adsGain_t; - -class Adafruit_ADS1015 -{ -protected: - // Instance-specific properties - uint8_t m_i2cAddress; - uint8_t m_conversionDelay; - uint8_t m_bitShift; - adsGain_t m_gain; - I2C* m_i2c; - - - public: - Adafruit_ADS1015(I2C* i2c = 0, uint8_t i2cAddress = ADS1015_ADDRESS); // set i2c adress = 0 to allow ADS1115 to use this as default constructor - uint16_t readADC_SingleEnded(uint8_t channel); - int16_t readADC_Differential_0_1(void); - int16_t readADC_Differential_2_3(void); - void startComparator_SingleEnded(uint8_t channel, int16_t threshold); - int16_t getLastConversionResults(); - void setGain(adsGain_t gain); - adsGain_t getGain(void); - - private: - uint16_t readRegister(uint8_t i2cAddress, uint8_t reg); - void writeRegister(uint8_t i2cAddress, uint8_t reg, uint16_t value); -}; - -// Derive from ADS1105 & override construction to set properties -class Adafruit_ADS1115 : public Adafruit_ADS1015 -{ - public: - Adafruit_ADS1115(I2C* i2c, uint8_t i2cAddress = ADS1015_ADDRESS); - - private: -}; \ No newline at end of file