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Diff: Adafruit_ADS1015.cpp
- Revision:
- 0:4dd9af114f46
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Adafruit_ADS1015.cpp Wed Mar 06 10:46:05 2019 +0000
@@ -0,0 +1,326 @@
+/**************************************************************************/
+/*!
+ @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
+ v1.1.1 - Ported to mbed
+*/
+/**************************************************************************/
+
+#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)
+{
+ 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(ADS1015) or 250(ADS1115) 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;
+}
+
+/**************************************************************************/
+/*!
+ @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(ADS1015) or 250(ADS1115) 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(ADS1015) or 250(ADS1115) 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(ADS1015) or 250(ADS1115) 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;
+ }
+}
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