Overview
Description
The RL78/G23 capacitive touch evaluation system makes it easy for users to evaluate touch solutions offered by Renesas. You can start evaluating immediately out of the box using the board and software included in each kit.
Configuration
- RL78/G23 CPU board
- Touch application board
- Self-capacitance evaluation board built-in basics for capacitive touch: switches, slider and wheel
Features
- Use to evaluate various touch functions (button, slider, wheel)
- Simple prototyping
- Use as a reference when designing boards or software
- Easily adjust the sensitivity by using QE for Capacitive Touch
- Easy operation with intuitive interface
- Easy to develop touch interfaces even for beginners with GUI
- Automatically output adjusted source code
- Compliant with IEC 61000-4-3 and IEC 61000-4-6 Level 3
Applications
Documentation
Featured Documentation
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| Type | Title | Date |
| Manual - Development Tools | PDF 959 KB 日本語 | |
| PCB Design Files | RTK0EG0030S01001BJ - Design Package
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| Application Note |
PDF
771 KB
日本語
AI-generated Summary:
The sample code enables capacitive touch functionality on the RL78/G23 microcontroller, supporting multiple electrodes including buttons, slider, wheel, and shield. It integrates LED control linked to touch inputs and CPU board push buttons. The system supports USB serial communication for serial monitoring and tuning at 115200bps. The software structure uses Smart Configurator-generated components and includes touch interface configuration, tuning, and sensitivity adjustment. Operation is confirmed on RL78/G23 at 32MHz with USB power. The package contains source files for touch control, LED functions, and peripheral configurations.
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| Application Note |
PDF
6.87 MB
日本語
Functional safety functions are becoming an important on system design as automatic electronic control systems continue to expand to a wide range of applications. This APN describes the software for capacitive touch sensor(CTSU) functional safety self test.
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| Tool News - Release | PDF 176 KB 日本語 | |
| Application Note |
PDF
3.46 MB
日本語
, 简体中文
This application note describes parameter tuning methods using QE for Capacitive Touch for microcontrollers that incorporate a Capacitive Touch Sensing Unit (CTSU).
In addition to the default auto-tuning process, it provides an overview of the Advanced mode and adjustable CTSU parameters for optimizing touch performance.
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| Application Note |
PDF
1.58 MB
日本語
AI-generated Summary:
The CTSU module integrates capacitive touch sensing functions for RL78 microcontrollers, supporting multiple peripheral types with distinct features. It enables various measurement modes such as self-capacitance, mutual capacitance, and current measurement, with advanced functions including sensor correction, initial offset adjustment, multi-frequency measurements, shield functionality, and automatic judgment. Measurements can be triggered by software or external events, with results obtained via APIs. The module also supports diagnosis, moving average filtering, and temperature correction. Multi-clock measurements reduce noise, and calibration functions ensure accurate sensor readings. The document details API usage, hardware/software requirements, and operational modes, providing comprehensive guidance for integrating capacitive touch sensing in embedded systems.
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| Application Note |
PDF
956 KB
日本語
AI-generated Summary:
The TOUCH Module integrates capacitive touch detection using the CTSU hardware, supporting buttons, sliders, and wheels with configurable settings via QE for Capacitive Touch. It processes periodic capacitance measurements to determine touch states, employing baseline calibration, drift correction, hysteresis, and debouncing to ensure accurate touch detection and reduce noise. The module supports both self-capacitance and mutual-capacitance buttons, with majority judgment modes for reliable input. It provides APIs for initialization, scanning, data retrieval, sensitivity adjustment, and drift control, enabling flexible integration into RL78 microcontroller applications.
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| Application Note |
PDF
14.40 MB
日本語
, 简体中文
This application note provides the design principles and layout examples of touch electrodes for microcontrollers embedded with a Capacitive Touch Sensing Unit (CTSU). It outlines recommended design practices and considerations for both self‑capacitance and mutual‑capacitance methods, covering electrode geometry, routing, and shielding structures. In addition, it describes the application examples for each sensing method.
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| Application Note |
PDF
2.42 MB
日本語
, 简体中文
AI-generated Summary:
Capacitive touch sensor microcontrollers utilize Renesas' Capacitive Touch Sensing Unit (CTSU) technology embedded in RX, RA, RL78 families, and Renesas Synergy™. The document explains capacitance detection principles, including self-capacitance and mutual-capacitance methods, and details the evolution from first-generation sensors to advanced CTSU2. It covers MCU lineups, hardware design guidelines, software configuration, tuning procedures, development environments, and evaluation kits to support capacitive touch product development. The CTSU converts capacitance changes into measurable signals, applying filtering and threshold judgment to detect touch inputs accurately.
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| Application Note |
PDF
842 KB
日本語
The Renesas board support package SIS module (r_bsp) forms the foundation of any project that uses Software Integration System (SIS) modules. The r_bsp is easily configurable and provides all the code needed to get the MCU and the board from reset to the main() function. This document describes r_bsp conventions and explains how to use it, configure it, and create a BSP for your own board.
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| Application Note | PDF 4.99 MB 日本語 | |
| Application Note |
PDF
8.65 MB
日本語
The Capacitive Touch Evaluation System for the RL78/G23 supports development with CS+, the standalone version of the Smart Configurator, and the standalone version of QE for Capacitive Touch. The standalone QE for Capacitive Touch enables flexible development independent of the device or integrated development environment (IDE). This application note describes the steps for developing capacitive touch applications using the Capacitive Touch Evaluation System.
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| Application Note |
PDF
1.50 MB
日本語
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.
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| Application Note |
PDF
1.75 MB
日本語
AI-generated Summary:
The document explains a method to achieve low power consumption in capacitive touch measurement using the RL78/G23 microcontroller's CTSU2L unit combined with the SNOOZE mode and a 32-bit interval timer. It details intermittent CPU operation controlled by the timer to reduce power usage to about 1/238 compared to continuous measurement. The system measures a single touch button at fixed intervals, activating full operation only upon touch detection. The guide covers peripheral module coordination, hardware and software setup, current consumption measurement, and sample code for implementing this low-power touch sensing solution.
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| Application Note | PDF 959 KB 日本語 | |
| Application Note |
PDF
14.17 MB
日本語
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.
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| Application Note |
PDF
4.05 MB
日本語
AI-generated Summary:
The document explains how to develop low power capacitive touch applications using the RL78 Family's SNOOZE Mode Sequencer (SMS). It details the procedure for implementing auto judgement measurement with SMS on RL78/G22 and RL78/G23 devices, including module flows, external pin wiring for RL78/G22, and software configuration steps. The guide covers project creation with Smart Configurator, touch interface development, sensor tuning with QE, and middleware integration to optimize capacitive touch functionality while minimizing power consumption.
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| Application Note |
PDF
2.18 MB
日本語
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.
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| Application Note |
PDF
1.47 MB
日本語
AI-generated Summary:
The document explains how to achieve low power consumption in capacitive touch measurement using the SNOOZE Mode Sequencer (SMS) function of the RL78/G23 MCU. SMS allows sequential execution of processes independently from the CPU during standby, reducing power usage by handling touch on/off detection for multiple electrodes. It details the peripherals involved, such as the Capacitive Sensing Unit (CTSU2L), timers, ELCL, and DTC, and outlines operation conditions, touch interface configuration, and measurement methods. The guide also covers current consumption measurement techniques and provides software flowcharts for touch measurement control in both low power and normal modes.
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| Application Note |
PDF
1.33 MB
日本語
AI-generated Summary:
The software implements self-capacitance waterproof touch buttons using the RL78/G23 MCU with CTSU2's active shield function to enhance noise immunity and water resistance. It addresses false detections caused by water droplets on GND shield buttons by driving the shield at the same potential as the electrode, canceling parasitic capacitance. The demo board includes both GND shield and active shield buttons for comparative evaluation, with LED indicators for touch detection. The document details hardware setup, software structure, and operational behavior, focusing on reducing false touch detection in wet environments.
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| Application Note |
PDF
228 KB
日本語
AI-generated Summary:
The RL78/G23 Capacitive Touch Evaluation System includes factory default firmware for the RL78/G23 MCU, enabling demonstration of capacitive touch functions. The firmware operates on a 5.0V supply and runs on the RL78/G23 CPU and application boards. Programming requires Renesas Flash Programmer and E2 Emulator Lite. The document details specifications, operation conditions, programming instructions, and provides references to user manuals and support resources. It also includes general precautions for handling microcontroller products, emphasizing ESD protection, power-on processing, signal input restrictions, and proper pin handling to ensure device reliability and safety.
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| Application Note |
PDF
1.63 MB
日本語
AI-generated Summary:
The Capacitive Touch Sensing Unit (CTSU2L) measures electrostatic capacitance changes caused by finger proximity using self-capacitance and mutual capacitance methods. It supports up to 32 channels depending on the device, with operating voltages from 1.8 to 5.5 V. The unit counts clock cycles to detect capacitance variations and includes features such as noise prevention, calibration, and low-power SNOOZE mode. It offers flexible measurement modes, power supply switching for transmit pins, and interrupt-driven data handling. The document details CTSU2L’s architecture, pin configurations, measurement principles, and operational settings for RL78 microcontrollers.
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23 items
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Design & Development
Software & Tools
Software & Tools
| Software title
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Software type
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Company
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| QE for Capacitive Touch: Development Assistance Tool for Capacitive Touch Sensors In developing embedded system using the capacitive touch sensor of MCUs, you can easily setup initial configurations of the touch interface as well as process the tuning of sensors, and reduce development time. [Plugin for Renesas IDE "e2 studio"] [Standalone Version] [Support MCU/MPU:RA, RL78, RX, Renesas Synergy™]
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Solution Toolkit | Renesas |
| E2 emulator [RTE0T00020KCE00000R] On-chip debugging emulator. Also available as a flash memory programmer. [Support MCU/MPU: RA, RE, RH850, R-Car D1, RL78, RX, RISC-V MCU]
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Emulator | Renesas |
| E2 emulator Lite [RTE0T0002LKCE00000R] On-chip debugging emulator. Also available as a flash memory programmer. [Support MCU/MPU: RA, RE, RL78, RX, RISC-V MCU]
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Emulator | Renesas |
| C Compiler Package for RL78 Family [CC-RL] C Compiler Package for RL78 Family [IDE: CS+, e² studio]
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Compiler/Assembler | Renesas |
| e² studio - information for RL78 Family Eclipse-based Renesas integrated development environment (IDE).
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IDE and Coding Tool | Renesas |
5 items
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Sample Code
Sample Code
Filters
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| Type | Title | Date Date |
| Sample Code | RL78 Family CTSU Module Software Integration System Rev.2.30 - Sample Code
Application:
Human Machine Interface (HMI)
Compiler:
CC-RL, ICCRL78
Function:
HMI, RL78 Software Integration System, Software Package
IDE:
e2 studio, IAR EWRL78
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| Sample Code | RL78 Family TOUCH Module Software Integration System Rev.2.30 - Sample Code
Application:
Human Machine Interface (HMI)
Compiler:
CC-RL, ICCRL78
Function:
HMI, RL78 Software Integration System, Software Package
IDE:
e2 studio, IAR EWRL78
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| Sample Code | RL78 Family Board Support Package Module Using Software Integration System Rev.1.92 - Sample Code
[Toolchains=CC-RL|V1.16.00;LLVM for Renesas RL78|17.0.1.202506;ICCRL|5.20.1]
ZIP
3.89 MB
Application:
Consumer Electronics, Industrial
Compiler:
CC-RL, ICCRL78, LLVM for Renesas RL78
Function:
BSP, Clock, Driver or Library
IDE:
e2 studio, IAR EWRL78
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| Sample Code | RL78 Family Using the standalone version of QE to Develop Capacitive Touch Applications Rev.2.00
[Toolchains=CC-RL|V1.15.01]
ZIP
27.34 MB
日本語
Application:
Human Machine Interface (HMI)
Compiler:
CC-RL
Function:
Application Example, HMI
IDE:
CS+ for CC
This is an example of a touch application developed using CS+ and the standalone version of QE for Capacitive Touch. Two types of projects are provided: a simple implementation example and an applied example, both of which can be immediately tested on the capacitive touch evaluation system. These can be used as reference materials to understand the development procedure in conjunction with the application note.
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| Sample Code | RL78/G23 Capacitive Touch Low Power Guide (SNOOZE Mode Function) Rev.2.00
[Toolchains=CC-RL|V1.15.00]
ZIP
9.21 MB
日本語
Application:
Consumer Electronics, Industrial
Compiler:
CC-RL
Function:
Application Example, HMI
IDE:
e2 studio
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| Sample Code | Capacitive Sensor MCU Capacitive Touch Software Filter Sample Program
[Software=RX Driver Package|V2.20;RA Flexible Software Package|v5.3.0],[Toolchains=CC-RL|V1.13.00;CC-RX|V3.06.00;GNU Arm Embedded|13.2.1.arm-13-7]
ZIP
16.10 MB
日本語
Application:
Consumer Electronics
Compiler:
CC-RL, CC-RX, GNU ARM Embedded
Function:
Application Example, HMI
IDE:
e2 studio
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| Sample Code | RL78/G23 Capacitive Touch Evaluation System Sample Code Rev.3.00
[Toolchains=CC-RL|V1.13]
ZIP
6.43 MB
日本語
Compiler:
CC-RL
Function:
Evaluation Kit, HMI
IDE:
e2 studio
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| Sample Code | RL78/G23 Capacitive Touch Low Power Guide (SMS function) Rev.1.10
[Toolchains=CC-RL|V1.13.00]
ZIP
10.68 MB
日本語
Compiler:
CC-RL
Function:
Application Example, HMI
IDE:
e2 studio
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| Sample Code | RL78/G23 Self-capacitance Waterproof Touch Button Demo Sample Software Rev.1.00 - Sample Code
Application:
Consumer Electronics, Industrial
Compiler:
GNU ARM Embedded
Function:
HMI
IDE:
e2 studio
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| Sample Code |
ZIP
509 KB
Application:
Consumer Electronics, Industrial
Function:
HMI
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10 items
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Related Boards & Kits
Boards & Kits
Reference Designs
Capacitive Touch Liquid Dispenser Reference Design
This capacitive touch liquid dispenser reference design is for hands-free dispensing of liquids such as soap, hand sanitizer, shampoo, or hand lotion. Automatic liquid dispensers are popular and eliminate bacterial transmission with touch-free designs. In recent years, these dispensers have... Read More
Reference Designs
Capacitive Touch Proximity Touch Reference Design
The Touchless Button Reference Design can detect the approach of fingers and hands without physical contact using Renesas’ capacitive touch solution. The electrode detects the proximity of the finger via self-capacitance and turns on the LED. The demo solution is compatible with all types of... Read More
Reference Designs
Capacitive Touch Liquid Level Indicator Reference Design
This reference design measures the water level with a one-channel self-capacitance electrode and a one-channel shield electrode using a Renesas capacitive touch key solution. Electrodes and liquid tanks need to be GND shielded with conductors, but the linear values can be measured with one... Read More
Product Options
| Part Number | Status | Stock | Budgetary Price (USD) | Sampleable |
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| RTK0EG0030S01001BJ | Active | In Stock | 1u | $152.94 | N/A |
Videos & Training
This video demonstrates how to implement automatic capacitive touch measurement using the SNOOZE Mode Sequencer (SMS) on RL78/G22 and RL78/G23, enabling a significant reduction in system operating current during touch measurements. Part 1 covers creating a project with Smart Configurator.
Additional Videos
Support
Support Communities
- RL78/G23 Capacitive Touch Low Power Support
Hello, We are working on a capacitive touch-based application and are looking to interface a capacitive touch sensor module with a BLE device (DA14531) or an MCU, and then transmit the data via BLE. Does the RL78/G23 MCU support this application? Thanks and Regards,
Nov 3, 2025
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