So hook up an arduino on USB (or 10 of them) and have all the GPIO you could possibly want. They're less expensive than a good USB cable, which also means that

So hook up an arduino on USB (or 10 of them) and have all the GPIO you could possibly want. They're less expensive than a good USB cable, which also means that if you make mistakes you blow up a $2 arduino rather than even a very cheap $200 pc (or even a $50 rPi)