Connection diagram PCF8575 and ULN2803A [SOLVED]

[Jose Zazo]

Again beginner doubts. I am designing a prototype PCB to facilitate the assembly (I would prefer to wait for the Ferduino Mega plate if possible its availability).

The schematic of the connection of the PCF8575 module and the integrated ULN2803A is that of the attached drawing. From what I have read (many of the images of photobucklet have disappeared) I think it is correct but the doubt that I have is if it would not be convenient to feed with 5V the common pin (10) of the ICs.



Thanks

[Fernando Garcia]

Hi!

You can but is not needed if you won't control motors (inductive load) like dosing pumps and fans directly.

Best regards.

-------------------------------- Last edited Wed Jul 19, 2017 9:51 am --------------------------------

Warning: Connect 5V to common if the ULN will work with 5V. If will work with 12V should connect to 12V.