HI. I would like to know if I can control 16 relays with arduino uno board and internet shield.
Thank you in advance
Presumably you are going to need a method of increasing the number of output pins. One way would be to use 2 cascaded 8 pin shift registers
This is probably not a programming question, but AFAICT the ethernet shield uses the SPI interface (pins 10..13) and that leaves 14 pins excluding pins 0 and 1 which are used by the serial interface. Controlling 16 relays would require some sort of shift register.