Class object scope if I2C address is unknown until setup()

Projects Programming
2

Rather than creating a third instance, use the version of .begin() that lets you set the address. Something like this should work:

#include <Adafruit_INA219.h>
const byte A_addr = 0x40; // address of sensor A (known)
const byte B_addr = 0x41; // address of sensor B (known)

Adafruit_INA219 ina;

byte C_addr = 0; // address of the connected INA sensor (unknown at this stage)

void setup() {
  // read bus voltage from first sensor
  ina.begin(A_addr);
  float A_voltage = ina.getBusVoltage_V();

  // read bus voltage from second sensor
  ina.begin(B_addr);
  float B_voltage = ina.getBusVoltage_V();

  // assign address of connected sensor to S_addr (range and error checking removed)
  if (A_Voltage > B_Voltage) {
    C_addr = A_addr;
  }
  else {
    C_addr = B_addr;
  }

  // Switch to the desired device
  ina.begin(C_addr);

  // now we have C_addr, but how to instantiate ina_C(C_addr) to make it accessible in loop()?
}