What do you mean by “pull the pin on the slave side”? Usually the master has full control over the SS pin, and the slave merely listens to know when it is being accessed.
Yes, I know I have to configure it as o/p high on master and I/p high on slave.
But I couldn’t find it on pro micro board.
The SS pin on the slave is supposed to be brought low to tell it that it’s being talked to, and otherwise kept high. On the master, I think the SS pin needs to be kept as an OUTPUT or high.
On the micro, this pin is PB0… which appears to be used for the RX light, and isn’t broken out.
Mangle or remove the LED, solder (and glue in place, else it’ll fatigue and break) a wire to the end that goes to the chip, and there’s your connection point.
It’s digital pin 17 from within code.
No, I don’t want to do this modification.
OK, I want to understand if they didn’t include the SS pin on the I/O pins, then how the pro micro suppose to work? would it work with only 3 pins? MOSI MISO SCK.