Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems.n 2012, 4-bit microcontrollers also see significant sales. In 2015, 8-bit microcontrollers can be bought for $0.311 (1,000 units), 16-bit for $0.385 (1,000 units), and 32-bit for $0.378 (1,000 units but at $0.35 for 5,000).