Added linux support.

Adafruit_ADS1X15.cpp

@@ -22,6 +22,7 @@
     v1.0  - First release
     v1.1  - Added ADS1115 support - W. Earl
     v2.0  - Refactor - C. Nelson
+    v3.0  - Added Linux support - HonestQiao
 
     @section license License
 
@@ -62,10 +63,28 @@ Adafruit_ADS1115::Adafruit_ADS1115() {
     @return true if successful, otherwise false
 */
 /**************************************************************************/
+#if defined(__linux__)
+bool Adafruit_ADS1X15::begin(uint8_t i2c_addr, int id) {
+  char i2c_device[15] = {0};
+  sprintf(i2c_device, "/dev/i2c-%d", id);
+  fd = open(i2c_device, O_RDWR);
+  if (fd < 0) {
+    return -1;
+  } else {
+    if (ioctl(fd, ADS1X15_I2C_SLAVE, i2c_addr) < 0) {
+      close(fd);
+      return -2;
+    } else {
+      return true;
+    }
+  }
+}
+#else
 bool Adafruit_ADS1X15::begin(uint8_t i2c_addr, TwoWire *wire) {
   m_i2c_dev = new Adafruit_I2CDevice(i2c_addr, wire);
   return m_i2c_dev->begin();
 }
+#endif
 
 /**************************************************************************/
 /*!
@@ -383,7 +402,11 @@ void Adafruit_ADS1X15::writeRegister(uint8_t reg, uint16_t value) {
   buffer[0] = reg;
   buffer[1] = value >> 8;
   buffer[2] = value & 0xFF;
+#if defined(__linux__)
+  write(fd, buffer, 3);
+#else
   m_i2c_dev->write(buffer, 3);
+#endif
 }
 
 /**************************************************************************/
@@ -397,7 +420,12 @@ void Adafruit_ADS1X15::writeRegister(uint8_t reg, uint16_t value) {
 /**************************************************************************/
 uint16_t Adafruit_ADS1X15::readRegister(uint8_t reg) {
   buffer[0] = reg;
+#if defined(__linux__)
+  write(fd, buffer, 1);
+  read(fd, buffer, 2);
+#else
   m_i2c_dev->write(buffer, 1);
   m_i2c_dev->read(buffer, 2);
+#endif
   return ((buffer[0] << 8) | buffer[1]);
 }

Adafruit_ADS1X15.h

@@ -16,14 +16,34 @@
 #ifndef __ADS1X15_H__
 #define __ADS1X15_H__
 
+#if defined(__linux__)
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define delay(x) usleep(1000 * x)
+#else
 #include <Adafruit_I2CDevice.h>
 #include <Arduino.h>
 #include <Wire.h>
+#endif
 
 /*=========================================================================
     I2C ADDRESS/BITS
     -----------------------------------------------------------------------*/
 #define ADS1X15_ADDRESS (0x48) ///< 1001 000 (ADDR = GND)
+#if defined(__linux__)
+#define ADS1X15_I2C_SLAVE (0x0703) // IIC SLAVE
+#endif
 /*=========================================================================*/
 
 /*=========================================================================
@@ -148,13 +168,21 @@ typedef enum {
 class Adafruit_ADS1X15 {
 protected:
   // Instance-specific properties
+#if defined(__linux__)
+  int fd;
+#else
   Adafruit_I2CDevice *m_i2c_dev; ///< I2C bus device
-  uint8_t m_bitShift;            ///< bit shift amount
-  adsGain_t m_gain;              ///< ADC gain
-  uint16_t m_dataRate;           ///< Data rate
+#endif
+  uint8_t m_bitShift;  ///< bit shift amount
+  adsGain_t m_gain;    ///< ADC gain
+  uint16_t m_dataRate; ///< Data rate
 
 public:
+#if defined(__linux__)
+  bool begin(uint8_t i2c_addr = ADS1X15_ADDRESS, int id = 0);
+#else
   bool begin(uint8_t i2c_addr = ADS1X15_ADDRESS, TwoWire *wire = &Wire);
+#endif
   int16_t readADC_SingleEnded(uint8_t channel);
   int16_t readADC_Differential_0_1();
   int16_t readADC_Differential_0_3();

examples/linux/singleended.cpp

@@ -0,0 +1,76 @@
+#include "../../Adafruit_ADS1X15.h"
+
+Adafruit_ADS1115 ads; /* Use this for the 16-bit version */
+// Adafruit_ADS1015 ads;     /* Use this for the 12-bit version */
+
+void setup(void) {
+  // Serial.begin(9600);
+  // Serial.println("Hello!");
+
+  // Serial.println("Getting single-ended readings from AIN0..3");
+  // Serial.println("ADC Range: +/- 6.144V (1 bit = 3mV/ADS1015,
+  // 0.1875mV/ADS1115)");
+  printf("Getting single-ended readings from AIN0..3");
+  printf("ADC Range: +/- 6.144V (1 bit = 3mV/ADS1015, 0.1875mV/ADS1115)");
+
+  // The ADC input range (or gain) can be changed via the following
+  // functions, but be careful never to exceed VDD +0.3V max, or to
+  // exceed the upper and lower limits if you adjust the input range!
+  // Setting these values incorrectly may destroy your ADC!
+  //                                                                ADS1015
+  //                                                                ADS1115
+  //                                                                -------
+  //                                                                -------
+  // ads.setGain(GAIN_TWOTHIRDS);  // 2/3x gain +/- 6.144V  1 bit = 3mV 0.1875mV
+  // (default) ads.setGain(GAIN_ONE);        // 1x gain   +/- 4.096V  1 bit =
+  // 2mV      0.125mV ads.setGain(GAIN_TWO);        // 2x gain   +/- 2.048V  1
+  // bit = 1mV      0.0625mV ads.setGain(GAIN_FOUR);       // 4x gain +/- 1.024V
+  // 1 bit = 0.5mV    0.03125mV ads.setGain(GAIN_EIGHT);      // 8x gain   +/-
+  // 0.512V  1 bit = 0.25mV   0.015625mV ads.setGain(GAIN_SIXTEEN);    // 16x
+  // gain  +/- 0.256V  1 bit = 0.125mV  0.0078125mV
+
+  if (!ads.begin()) {
+    // Serial.println("Failed to initialize ADS.");
+    printf("Failed to initialize ADS.");
+    while (1)
+      ;
+  }
+}
+
+void loop(void) {
+  int16_t adc0, adc1, adc2, adc3;
+  float volts0, volts1, volts2, volts3;
+
+  adc0 = ads.readADC_SingleEnded(0);
+  adc1 = ads.readADC_SingleEnded(1);
+  adc2 = ads.readADC_SingleEnded(2);
+  adc3 = ads.readADC_SingleEnded(3);
+
+  volts0 = ads.computeVolts(adc0);
+  volts1 = ads.computeVolts(adc1);
+  volts2 = ads.computeVolts(adc2);
+  volts3 = ads.computeVolts(adc3);
+
+  // Serial.println("-----------------------------------------------------------");
+  // Serial.print("AIN0: "); Serial.print(adc0); Serial.print("  ");
+  // Serial.print(volts0); Serial.println("V"); Serial.print("AIN1: ");
+  // Serial.print(adc1); Serial.print("  "); Serial.print(volts1);
+  // Serial.println("V"); Serial.print("AIN2: "); Serial.print(adc2);
+  // Serial.print("  "); Serial.print(volts2); Serial.println("V");
+  // Serial.print("AIN3: "); Serial.print(adc3); Serial.print("  ");
+  // Serial.print(volts3); Serial.println("V");
+  printf("-----------------------------------------------------------\n");
+  printf("AIN0: %d %f V\n", adc0, volts0);
+  printf("AIN0: %d %f V\n", adc1, volts1);
+  printf("AIN0: %d %f V\n", adc2, volts2);
+  printf("AIN0: %d %f V\n", adc3, volts3);
+
+  delay(1000);
+}
+
+int main(int argc, char *argv[]) {
+  setup();
+  while (true) {
+    loop();
+  }
+}