This application note explains two control methods and a calibration algorithm for Cypress four‑wire capacitive touchscreen controllers using the CY8C27443…
The document introduces Cypress PSoC‑based four‑wire capacitive touchscreen control, describing the touchscreen structure, voltage paths, measurement methods, and a calibration algorithm that removes scaling errors and mechanical mis‑alignment. It also shows how to convert touchscreen coordinates to display coordinates such as an LCD.
Implementation details cover the use of PGA and ADC modules, voltage levels for X and Y lines, resistor values, and the processing flow for touched and untouched states. The note includes example circuit configurations, ADC settings, and sample code snippets for both CY8C27443 and CY8C24423 devices. This manual is written in Chinese.