I2C address keeps changing

ESPHome
1

Hi, I am using an ESP8266 wemos D1 Mini and a INA3221.

When scanning the bus, the address keeps changing between 0x40 and 0x43.

Every time I enter the address in the sensor component, connection to the INA3221 fails, when I check the I2C bus scan results, the address has changed?

Any idea whats going on here, have never seen this before.

2

Did you leave A0 floating?

3

Yes, A0 is floating?

4

Well, it shouldn’t

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5

Wait, im so confused. I set one of these up previously and I did not do this.

Ok, so I can short A0 to any one of those pins to address it?

6

Had similar experience with couple of PCF8574:

  • one device reponded on same address with all A pins floating,
  • buty another chnaged address on almost every start.

Hint for me: always connect A pins, not leave them floating - result is much more predictable.

7

Depending on to what you short A0, you’ll get a different (but stable) address.
It probably worked for your previous experiment by sheer luck.

8

Damn thanks, this is new to me, didn’t even know about this haha.

Thanks guys!

9

One more question, does this jumper need to remain in place for the entire time of use for the address to remain, or just once?

Thanks

10

Looking at the pinout, there is no A0 pin.

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11

Damn ok sorry just found it its a jumper on the board.