I’m using INA219 chip to measure voltage and current. I have three INA219 chips and I have checked readings on serial monitor by using each of them. All of these chips are accurate in load voltage but they have different shunt voltages calculation on same circuit i designed to check results. I swap them and check readings where current calculations vary on each of these INA219 chip due to different shunt voltage. All of them has R100 shunt resistor but they have different readings. What’s the reason?
With all electronic devices there is no guarantee two of the same device will perform exactly the same. But they should be close to each other and within the range specified in the datasheet.
What is the variation in readings between the 3 devices ??
How much current is flowing through the shunt ??
EDIT: The data sheet mentions a Calibration Register. I imagine the values placed in this register would be different between the 3 devices so they all end up with similar values for a given situation.