A while ago I received a couple of I/O port expander modules that use the I 2 C protocol. Using that Chinese module, you can use only the SDA and SCL pins of your Arduino, or any microcontroller ...
“You can’t put new wine in old bottles” – so the saying goes. But you would if you’re a hacker stuck with a radio built in 2005, which looked like it was put together using technology from 1975.