SX1509 internal pulldown failing

SPARK-X
1

Looking for some help.
Connected a SX1509 to ESP32 running ESPhome.
I’ve selected “Pulldown: true” option for 4 of the GPIOs and initially they worked ok.
But over night these GPOI’s have lost the pull down resistor somehow.
The input/gpio is now floating 1.2vdc.
One of the gpio’s i had set to pullup but it now is floating too.

2

I’d sooner suspect fluctuating power or something…are you using a means-well supply? Can you put one on a big battery to run overnight to test with?

3

Hi
It’s a Poe device (Olimex ESP32-POE-ISO)
Yes something not right ill have to try a different power supply.
Thank you

4

Looks like a I2C problem only when i have two of the SX1509 connected.

Should i be removing one set of pullup resistors (SJ1) if im connecting two SX1509’s on the same bus?

thanks

5

Yes, you should only have one set of pull ups on the I2C bus at a time.

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