IC2 and 74hc595

i have no code to offer because i need some quick knowledge and then advice.

does the info that gets sent to the pin stay there? is it stored at "pin" 16? or is it just a transient thing where the data is passing by.

can the new locations be set as variables?

is it possible to address a certain location, like pin 16 up to pin 25 with the right number ICs.

thank you,

best

tony

I2C and 74HC595 do not go together. HC595 does not have a way to drive the ACK bit of an I2C transfer.

SPI is much better:

digitalWrite (latchPin, LOW); // I use the SS pin for this, D10 on an Uno
SPI.transfer(dataToGoOut); // default clock speed 4 MHz on SCK, data goes out on MOSI
digitalWrite (latchPin, HIGH); // outputs update and stay there until another rising edge on this pin

Some also use software SPI to accomplish that, at a much slower data rate.