A library for ADS1015 and ADS1115 from Texas Instruments.

Dependents:   IGGE_Power ADS1015-hello_world ADS1115-hello_world frdm_rtos_Eth ... more

Use like this

#include "mbed.h"
#include "Adafruit_ADS1015.h"
#include "USBSerial.h"

#define SERIAL_BAUD_RATE    9600

I2C i2c(p23, p18);
Adafruit_ADS1015 ads(&i2c);
USBSerial pc; // USB CDC serial port

 
int main() {
    uint16_t reading;
    while (1) {
        reading = ads.readADC_SingleEnded(0); // read channel 0
        pc.printf("reading: %d\r\n", reading); // print reading    
        wait(2); // loop 2 sek
    }
}

Library ported from Arduino at github repository.

Breakout boards from Adafruit: http://learn.adafruit.com/adafruit-4-channel-adc-breakouts/overview

GitHub repository: https://github.com/adafruit/Adafruit_ADS1X15

Files at this revision

API Documentation at this revision

Comitter:
arve0
Date:
Sat Oct 11 08:44:20 2014 +0000
Parent:
2:d864e21d4e58
Parent:
3:fb735fb343de
Child:
5:aa277517f0ad
Commit message:
merged ads1115 changes

Changed in this revision

Adafruit_ADS1015.cpp Show annotated file Show diff for this revision Revisions of this file
Adafruit_ADS1015.cpp.orig Show annotated file Show diff for this revision Revisions of this file
Adafruit_ADS1015.h Show annotated file Show diff for this revision Revisions of this file
--- a/Adafruit_ADS1015.cpp	Sat Oct 11 08:20:09 2014 +0000
+++ b/Adafruit_ADS1015.cpp	Sat Oct 11 08:44:20 2014 +0000
@@ -119,7 +119,7 @@
                       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_DR_1600SPS   | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
                       ADS1015_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)
 
     // Set PGA/voltage range
@@ -170,7 +170,7 @@
                       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_DR_1600SPS   | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
                       ADS1015_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)
 
     // Set PGA/voltage range
@@ -218,7 +218,7 @@
                       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_DR_1600SPS   | // 1600(ADS1015) or 250(ADS1115) samples per second (default)
                       ADS1015_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)
 
     // Set PGA/voltage range
@@ -267,7 +267,7 @@
                       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_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
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Adafruit_ADS1015.cpp.orig	Sat Oct 11 08:44:20 2014 +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 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 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;
+    }
+}
\ No newline at end of file
--- a/Adafruit_ADS1015.h	Sat Oct 11 08:20:09 2014 +0000
+++ b/Adafruit_ADS1015.h	Sat Oct 11 08:44:20 2014 +0000
@@ -77,13 +77,13 @@
     #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_DR_128SPS    (0x0000)  // 128 samples per second - ADS1115 8SPS
+    #define ADS1015_REG_CONFIG_DR_250SPS    (0x0020)  // 250 samples per second - ADS1115 16SPS
+    #define ADS1015_REG_CONFIG_DR_490SPS    (0x0040)  // 490 samples per second - ADS1115 32SPS
+    #define ADS1015_REG_CONFIG_DR_920SPS    (0x0060)  // 920 samples per second - ADS1115 64SPS
+    #define ADS1015_REG_CONFIG_DR_1600SPS   (0x0080)  // 1600 samples per second - ADS1115 250SPS (default)
+    #define ADS1015_REG_CONFIG_DR_2400SPS   (0x00A0)  // 2400 samples per second - ADS1115 475SPS
+    #define ADS1015_REG_CONFIG_DR_3300SPS   (0x00C0)  // 3300 samples per second - ADS1115 860SPS
 
     #define ADS1015_REG_CONFIG_CMODE_MASK   (0x0010)
     #define ADS1015_REG_CONFIG_CMODE_TRAD   (0x0000)  // Traditional comparator with hysteresis (default)