I need additional GPIO's to control various Relays etc.
My primary PCB has both UART and I2C output ports, therefore i can either connect any additional PCB with an AVR or a GPIO IC such as TCA9534A.
What is the best way to create additional GPIOS?
Use a device like TCA9534A or an AVR?
I might be wrong but using multiple TCA9534A would be the simplest way?