PCF8575 Does not work with my code....

[Ioannis]

I measured short circuit current of PCF8575 outputs. It is roughly 0.16mA.

The ULN2803 needs at least 0.35mA, so practically 8575 cannot drive it with enough current.

perhaps you should write to them , the graphs in figures 8,9 and 10 are questionable . perhaps the scale should be uA not mA

Seems the datasheet has many errors...

Ioannis