Hello everyone, i come from electricians world. This question may sound stupid for you all, but when i try to start here i need to understand some things. 1st one is to know exactly what things can a shift register do and not do with an arduino in particular, so here is the question.
¿Do communicate in both directions, i mean, is it possible to get more inputs and outputs with a shift register or just only outputs?
It depends on the specific shift registers you select. Most are either serial in/parallel out for providing more digital output pins. Others are parallel in/serial out for providing more digital input pins.
There were older TTL chips avalible that could do both if wired and controlled correctly, but most only held 4 bits per package and not really that easy to work with for arduino projects.
There were older TTL chips avalible that could do both if wired and controlled correctly, but most only held 4 bits per package and not really that easy to work with for arduino projects.
The 74HC299 8-bit SR can shift either way and has parallel load and parallel tri-state output, so its pretty flexible. However it doesn't have latches like the 74HC595 (which is only serial->parallel).