RAK16000_DcCurrent_INA219.ino

/**
   @file RAK16000_DcCurrent_INA219.ino
   @author rakwireless.com
   @brief Get DC current from sensor
   @version 0.1
   @date 2021-7-28
   @copyright Copyright (c) 2020
**/

#include <Wire.h>    
#include <INA219_WE.h>// Click here to get the library: http://librarymanager/All#INA219_WE
#define I2C_ADDRESS 0x41

INA219_WE ina219 = INA219_WE(I2C_ADDRESS);


void setup()
{
  Serial.begin(115200);
  Serial.println("Initializing...");
  pinMode(WB_IO2, OUTPUT);
  digitalWrite(WB_IO2, HIGH);
  delay(300);
  // Initialize sensor
  Wire.begin();
  if(!ina219.init()){
    Serial.println("INA219 not connected!");
  }
  /* Set ADC Mode for Bus and ShuntVoltage
  * Mode *            * Res / Samples *       * Conversion Time *
  BIT_MODE_9        9 Bit Resolution             84 µs
  BIT_MODE_10       10 Bit Resolution            148 µs  
  BIT_MODE_11       11 Bit Resolution            276 µs
  BIT_MODE_12       12 Bit Resolution            532 µs  (DEFAULT)
  SAMPLE_MODE_2     Mean Value 2 samples         1.06 ms
  SAMPLE_MODE_4     Mean Value 4 samples         2.13 ms
  SAMPLE_MODE_8     Mean Value 8 samples         4.26 ms
  SAMPLE_MODE_16    Mean Value 16 samples        8.51 ms     
  SAMPLE_MODE_32    Mean Value 32 samples        17.02 ms
  SAMPLE_MODE_64    Mean Value 64 samples        34.05 ms
  SAMPLE_MODE_128   Mean Value 128 samples       68.10 ms
  */
  ina219.setADCMode(SAMPLE_MODE_128); // choose mode and uncomment for change of default
  
  /* Set measure mode
  POWER_DOWN - INA219 switched off
  TRIGGERED  - measurement on demand
  ADC_OFF    - Analog/Digital Converter switched off
  CONTINUOUS  - Continuous measurements (DEFAULT)
  */
  ina219.setMeasureMode(CONTINUOUS); // choose mode and uncomment for change of default
  
  /* Set PGain
  * Gain *  * Shunt Voltage Range *   * Max Current (if shunt is 0.1 ohms) *
   PG_40       40 mV                    0.4 A
   PG_80       80 mV                    0.8 A
   PG_160      160 mV                   1.6 A
   PG_320      320 mV                   3.2 A (DEFAULT)
  */
  ina219.setPGain(PG_320); // choose gain and uncomment for change of default
  
  /* Set Bus Voltage Range
   BRNG_16   -> 16 V
   BRNG_32   -> 32 V (DEFAULT)
  */
  ina219.setBusRange(BRNG_32); // choose range and uncomment for change of default
  ina219.setShuntSizeInOhms(0.1); // we use 100ohm
  Serial.println("INA219 Current Sensor Example Sketch - Continuous");

  /* If the current values delivered by the INA219 differ by a constant factor
     from values obtained with calibrated equipment you can define a correction factor.
     Correction factor = current delivered from calibrated equipment / current delivered by INA219
  */
  ina219.setCorrectionFactor(0.99); // insert your correction factor if necessary
}

void loop()
{
  float shuntVoltage_mV = 0.0;
  float loadVoltage_V = 0.0;
  float busVoltage_V = 0.0;
  float current_mA = 0.0;
  float power_mW = 0.0; 
  bool ina219_overflow = false;
  
  shuntVoltage_mV = ina219.getShuntVoltage_mV();
  busVoltage_V = ina219.getBusVoltage_V();
  //here we use the I=U/R to calculate, here the Resistor is 100mΩ, accuracy can reach to 0.5%.
  current_mA = shuntVoltage_mV/0.1;
  power_mW = ina219.getBusPower();
  loadVoltage_V  = busVoltage_V + (shuntVoltage_mV/1000);
  ina219_overflow = ina219.getOverflow();
  
  Serial.print("Shunt Voltage [mV]: "); Serial.println(shuntVoltage_mV);
  Serial.print("Bus Voltage [V]: "); Serial.println(busVoltage_V);
  Serial.print("Load Voltage [V]: "); Serial.println(loadVoltage_V);
  Serial.print("Current[mA]: "); Serial.println(current_mA);
  Serial.print("Bus Power [mW]: "); Serial.println(power_mW);
  if(!ina219_overflow){
    Serial.println("Values OK - no overflow");
  }
  else{
    Serial.println("Overflow! Choose higher PGAIN");
  }
  Serial.println();
  
  delay(1000);
}