I wish to connect a 4x4 keypad to the to UNO board using the SPI connector and the SPI library, does this mean the DIO pins 10 through 13 cannot be used for other purposes at the same time?
Arthur168:
I wish to connect a 4x4 keypad to the to UNO board using the SPI connector and the SPI library, does this mean the DIO pins 10 through 13 cannot be used for other purposes at the same time?
That is correct. They cannot be used. D11 to D13 are data and clock lines, and D10 is the slave select if you are using it for your keypad.