Introduction Traditional ultrasonic distance sensors (e.g., HC-SR04) typically require a dedicated microcontroller (MCU) to trigger the sensor and measure the echo pulse width. However, PSoC (Programmable System-on-Chip) devices from Infineon (formerly Cypress) offer a unique, integrated alternative. By combining configurable analog blocks, digital logic, and an ARM Cortex-M CPU, a PSoC can implement an ultrasonic sensor interface with minimal external components and advanced signal processing. How It Works (PSoC Implementation) In a PSoC-based ultrasonic system, the device generates a 40 kHz square wave using a TCPWM (Timer/Counter/PWM) block. This signal drives an external ultrasonic transmitter (e.g., 40 kHz transducer). Simultaneously, the PSoC’s analog front end—utilizing an opamp, comparator, and analog multiplexer—conditions the echo signal received by a matching receiver transducer.
