I saw several posts for SPI communication where they only explain that if a master wants to communicate with a slave, it will turn the CS/SS line low for the respective slave device.
In my application, the slave device (microcontroller) needs to send the data to the master device (Raspberry Pi) at irregular intervals. How can I let the master device know that slave wants to communicate? When the master needs to communicate, it will pull the CS/SS line low. Is there anything that the slave can do if it wants to talk to the master?
I saw some posts on this website itself that state that some devices use interrupts to let the master device know that the slave wants to send anything. Does the Raspberry Pi have the feature to detect interrupts from a slave device, or I would need to do polling from the Raspberry Pi side so that it is always ready whenever MCU sends data? Is there any other way?