I told above:
Fernando Garcia wrote:
The solution could be bypass the ULN and change on code LOW to HIGH and HIGH to LOW.
But I'm not sure if PCF can manage the current of all relays.
If the circuit is working as I told above to prevent damage PCF I think that ULN could be replaced by a PNP transistor array and TD62384AP
Jose Zazo wrote:
I had to compile the code with the PCF8575.h library since with the mxUnifiedPCF8574.h it gives me a compilation error (I have previously installed the library).
The function digitalRead
doesn't work correctly in PCF8575.h
for this reason I have replaced by mxUnifiedPCF8574.h
Show me the compiling error and let's fix.