Capacitive Touch Evaluation System for RX261

AI-generated Summary: The RX261 Capacitive Touch Evaluation System sample code enables control of capacitive touch electrodes including buttons, slider, and wheel, integrating LED control and USB serial communication for tuning and monitoring. It operates on the RX261 MCU at 64MHz and 5V, using software components generated by the smart configurator and QE for Capacitive Touch. The code structure includes touch configuration, LED control linked to touch inputs and CPU board switches, and supports serial tuning via UART. The package contains source files, configuration headers, and peripheral driver components necessary for development and evaluation.

AI-generated Summary: The CTSU module enables capacitive touch measurements across various RX Family MCUs, supporting multiple CTSU peripheral versions with distinct functions. It facilitates touch sensing through software or external triggers, provides sensor CCO correction for accurate readings, and includes initial offset adjustment to compensate parasitic capacitance. The module supports multi-frequency measurements to reduce noise and offers advanced features such as shield functions, diagnosis, and automatic corrections. APIs allow control over measurement start, data retrieval, and calibration. The document details measurement modes, timing, and integration with firmware, enabling precise capacitive touch applications in embedded systems.

AI-generated Summary: Capacitive touch sensors measure capacitance changes caused by finger contact using a sensor drive pulse and current measurement. Ripple noise from the power supply or peripheral circuits distorts these measurements by adding noise currents, causing inaccurate touch detection. To ensure high accuracy and reliability, power supply design must minimize ripple noise. The document explains measurement principles, ripple noise effects, and countermeasures including power supply circuit selection, switching circuits, board layout, and touch parameter tuning. It covers RX, RL78, and RA family MCUs embedding CTSU1 and CTSU2 types of capacitive touch sensing units.

AI-generated Summary: The guide explains methods to enhance noise immunity for capacitive touch sensor MCUs by addressing environmental noise issues that affect capacitance measurements. It covers noise types such as radiated RF, conducted noise, electrostatic discharge (ESD), and electrical fast transients (EFT), referencing IEC 61000-4 standards. The document details hardware and software countermeasures, including board design, multi-frequency measurement, filtering techniques, and protection circuits. It targets RX, RA, RL78 MCU families and Renesas Synergy devices embedding the CTSU module, providing practical design guidelines and evaluation results to ensure stable capacitive touch operation under noisy conditions.

AI-generated Summary: The software filters for capacitive touch systems include FIR, IIR, single-pole IIR, and median filters, each with detailed specifications, usage examples, and API descriptions. The document covers embedding these filters into existing projects for RA2L1, RX130, and RL78/G16 microcontroller groups, detailing operation conditions, software configuration, and filter parameter adjustments. It also provides development environment and hardware setup information to support capacitive touch evaluation systems.