Update getcurrent.ino

[phaelbotelho]

The load voltage must be the bus voltage minus the shunt resistor voltage. In a series circuit some voltage drop will exist in the shunt resistor, and this voltage dont go to the load, to compute the load voltage is necessary to subtract the shunt voltage from the bus Voltage. Just a sign change, but its make total difference in the values.

Thanks for attention!

[Koepel]

Hi, can you have a look at this video at 3:51 https://training.ti.com/engineer-it-how-simplify-high-voltage-current-measurement
He really says "load voltage" to the voltage before the shunt (VIN+).

I spent some time at the website of Texas Instruments. The "load voltage" is sometimes used for the voltage before the shunt (VIN+) and sometimes after the shunt (VIN-). The name "bus voltage" is always used for the voltage before the shunt with only one exception: the datasheet of the INA219. In the datasheet of the INA219, the "bus voltage" has become the voltage after the shunt.

Your pull request would not fix the confusion. Join me with Issue #49

[Escrich]

What about to raise the range to 30A?, the first step is to change the shunt by a 0,01 Ohm one, why not create a calibration line of for example ina219.setCalibration_16V_32A(); ?