user61047: I’ve checked the nano’s tech specs but I can’t seem to find any information regarding it. I’ve tried setting it to pin 26 (digital output)

user31105: The following answer assumes the Arduino is the master.
You can use any pin for that (at least any GPIO pin).
Multiple SPI devices can be connected to a SPI peripheral on an Arduino (in principle).
Every SPI device should have their own CS/CC pin, and is mandatory when you use multiple SPI devices.
For this reason, there is no single pin the SPI can define for being used as CS/CC pin. However, it should give a GND or VCC value, thus a CS/CC pin should typically be configured as a digital input pin (as master) for each slave.
(See remark of KIIV too); as slave the CS/CC pin should be a digital output pin.
For the other pins (MOSI, MISO, CLK), the Arduino uses a fixed set of pins because all SPI devices will be connected to these pins.
So the CS pin is configurable, and the other spi pins are fixed.

61047: <p>I’ve checked the nano’s tech specs but I can’t seem to find any information regarding it. I’ve tried setting it to pin 26 (digital output)</p>
 31105: <p>The following answer assumes the Arduino is the master.</p>

<p>You can use any pin for that (at least any GPIO pin).</p>

<p>Multiple SPI devices can be connected to a SPI peripheral on an Arduino (in principle).</p>

<p>Every SPI device should have their own CS/CC pin, and is mandatory when you use multiple SPI devices.</p>

<p>For this reason, there is no single pin the SPI can define for being used as CS/CC pin. However, it should give a GND or VCC value, thus a CS/CC pin should typically be configured as a digital input pin (as master) for each slave.
(See remark of KIIV too); as slave the CS/CC pin should be a digital output pin.</p>

<p>For the other pins (MOSI, MISO, CLK), the Arduino uses a fixed set of pins because all SPI devices will be connected to these pins.</p>

<p>So the CS pin is configurable, and the other spi pins are fixed.</p>
