Hi,
I want to use several GPIOs to control 10+ LED, so I selected MCP23S17 IC.
I wan to use 2 GPIO to simulate SPI interface to control MCP23S17 IC.
I am not sure about my config, pls comment, thanks.
1. _CS link to GND is right? In code, if it is needed to set _CS to 1 or 0?
2. The STM32 only set MCP23S17, and doen't need feedback from MCP23S17, so SO in NC, OK?
3. Do SCK and SI need 10K pullup to +5V or +3.3V?
4. I saw some design leave INTA and INTB NC, do these int need config by SW ? Or my design just link them to GND, right?