Dear Chao Chen ,
The same program is used, a total of 3 PCAL9722, selected through SPI chip select.
[A] Thank you for your answer. How many of the tested PCAL9722 are working correctly? From how many PCAL9722 working correctly are the 3 PCAL9722 faulty?
Please also answer following.
Please share a code where you are reading the input registers.
Please confirm a source of the PCAL9722 components. Have you purchased them from one of our authorized distributors? Please see this link for a list of our authorized distributors.
With Best Regards,
Joseph