Using USB and SPI at the same time with PIC18F4550

[nooobboy4321]

Hi, I'm working with my project using PIC18F4550, my goal is to expand my I/O ports so I guess I need a Port Expander like MCP23S17 and connect my PIC18F4550 with USB and the PC. My first plan is to use the USART(RS232 Serial Communication to PC) but I see a little bit details of PIC18F4550's Datasheet and I notice that RC7 has RX(for USART) and SDO(for SPI) shared together. I'm thinking of using USB as a communication between PC instead of USART. So my question, is it possible to use both USB and SPI? Thank you.

It's like this :

[PC] <<USB>> [PIC] <<SPI>> [MCP]

 

[wp100]

Hi,

Yes, you should be able to use USB and SPI together as they do not share pins.

You could also run SPI and rs232 if you used a Software Usart with some other free i/o pins, don't know if your C library will have one though ? - might find one ready made on the web.

 

[nooobboy4321]

Thank you for the quick reply wp100, it saves my time and effort in looking some forums about my problem.