AN60639 - PSoC® 1 Piezo Keypad Implementation | Cypress Semiconductor
AN60639 - PSoC® 1 Piezo Keypad Implementation
AN60639 describes the implementation of a piezo keypad using PSoC® 1. The solution described here provides reliable operation and a press time detection of up to two minutes.
Piezo sensors enable touch detection in the presence of metal surfaces, under water, in industrial environments with strong electrical fields, and in the chemical industry. They work on various surfaces including metal. Piezo sensors convert applied force into voltage. Therefore, they are not sensitive to external electrical and magnetic fields, water drops, or grounded surfaces.
This application note discusses a simple and cost effective solution to scan a piezo keypad without external components.