Should the touch interface use USB or IIC (I²C)?
When integrating a touchscreen into an embedded or industrial device, engineers often face a common question: Should the touch interface use USB or IIC (I²C)? At first glance, the difference may appear trivial—just two different communication connectors. However, the choice between a USB touch interface and an IIC touch interface can significantly impact system architecture, software development workload, and overall integration complexity. It also explains a common observation in many projects: USB touch screens are usually more expensive than IIC touch screens. Understanding why requires looking deeper into how these interfaces work at the system level. Understanding USB and IIC Touch Interfaces Both USB and IIC interfaces are widely used in capacitive touch screen systems , but they serve different purposes in system communication. IIC (I²C) is a widely used internal communication bus for embedded devices. In a touch system, the touch controller acts as a slave devi...