I recently received my two different INA219 breakout boards. One is purple and one is blue. Both from ebay.
Using the standard library the purple one is working great. But the blue one is not so much.
The shunt voltage is showing -2mV when nothing is connected over the shunt. But when I add my load all readings goes to Zero. Even while my LED bar is lighted.
The purple one is also showing -2mV over shunt but when load is connected I get the expected readings.
Can the blue one be faulty right from the go?
May there perhaps be different internal registers?
I did do an I2C scan sketch. The INA address is 0x40. The arduino also reports it like this.