Design of High-Precision Infrared Multi-Touch Screen Based on the EFM32

Due to the low accuracy of traditional infrared multi-touch screen, it’s difficult to ascertain the touch point. Putting forward a design scheme based on ARM Cortex-M3 kernel EFM32 processor of high precision infrared multi-touch screen. Using tracking scanning area algorithm after accessed electricity for the first time to scan, it greatly improved the scanning efficiency and response speed. Based on the infrared characteristic difference, putting forward a data fitting algorithm, employing the subtraction relationship between the covering area and sampling value to curve fitting, concluding the infrared sampling value of subtraction characteristic curve, establishing a sampling value differential data tables, at last ensuring the precise location of touch point. Besides, practices have proved that the accuracy of the infrared touch screen can up to 0.5 mm. The design uses standard USB port which connected to the PC can also be widely used in various terminals