wiz820io and 595 sharing spi

[Nick1802]

hey anyone that can help

im wanting to use the wiz820io and 595 but im unsure how to use both at the same time.

do i just pull cs to the wiz high and the 595 low when ever its time to transmit to it?

if this is not right then how would i go about this?

thanks in advance,
nick

 

[raphaelcno]

do i just pull cs to the wiz high and the 595 low when ever its time to transmit to it?

Yes, the CS signal is active low, so you pull CS to wiz820io high and CS to 595 low when you want to communicate with 595.

 

[PaulStoffregen]

The simplest way is to connect the '595 to 3 completely separate pin and use digitalWrite in a loop (or just 8 copies) to send the data to the shift register.

Or you can connect the '595 to MOSI and SCLK, and use one more pin to strobe it after you've used SPI to send the data you want.