Some other solutions for extra IO would be to buy an Arduino Mega with 54 digital IO pins or the Muxshield which gives you 48 IO (and is stackable for other shields). An advantage of using the two ...

IPS4260L low-side driver has four outputs for driving loads with one side connected to supply voltage, each individually ...

Multi-voltage programmable digital IO for SD/MMC card application; Cell Size (Width * height) 55um * 135um with DUP in-line bonding pads; Work voltage: 1.8V~3.3V power; Programmable 6 level ...