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This example demonstrates implementing CapSense buttons and slider for PSoC 6 MCU with Mbed OS.

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PSoC 6 MCU: CapSense Buttons and Slider

This code example demonstrates implementing CapSense® buttons and slider for PSoC® 6 MCU with Mbed OS using the CapSense Middleware Library and Mbed OS v5.15.1. This example features a 5-segment CapSense slider and two CapSense buttons.


Supported Kits (Target Names)

Hardware Setup

This example uses the kit’s default configuration. Refer to the kit guide to ensure that the kit is configured correctly. Since this example is designed to work at the default operating voltage of the kit, ensure that the power setting jumper when present is configured at the default position. For the kits that support multiple operating voltages, see Operation at Custom Power Supply Voltage to run this example at a non-default voltage.

Note: The PSoC 6 BLE Pioneer Kit and the PSoC 6 WiFi-BT Pioneer Kit ship with KitProg2 installed. ModusToolbox software requires KitProg3. Before using this code example, make sure that the board is upgraded to KitProg3. The tool and instructions are available in the Firmware Loader GitHub repository. If you do not upgrade, you will see an error like “unable to find CMSIS-DAP device” or “KitProg firmware is out of date”.

Software Setup

This example requires CapSense Tuner, which is installed as part of ModusToolbox™ IDE v2.0. Refer to the ModusToolbox Installation Guide for installation instructions.

This example also requires a terminal emulator. Instructions in this document use the terminal provided by Mbed CLI.

Using the Code Example in Mbed CLI Tools

  1. Import the code example into your mbed directory using the following mbed command:

mbed import

  1. Change the working directory to the code example folder:

cd mbed-os-example-capsense

  1. Connect the board to your PC using the provided USB cable through the USB connector.

  2. Put the kit in DAPLink mode to allow programming from Mbed CLI. See Firmware-loader to learn to update the firmware and switch to DAPLink mode.

  3. Compile the code and program the target board:

mbed compile --target CY8CPROTO_062_4343W --toolchain GCC_ARM --flash --sterm

Note: With the --sterm option, Mbed CLI opens a serial terminal with 9600-8N1 as the setting after programming completes. Do not use this option if you want to connect using another serial terminal application.


  1. After programming, the following message is displayed on the terminal when the application starts running:

Application has started. Touch any CapSense button or slider.

  1. Touch the buttons or the slider to observe the User LED changing its state (ON when touched and OFF when not touched) and the status printed on the serial terminal.

  2. You can also monitor the CapSense data using the CapSense Tuner application as follows:

Monitor Data Using CapSense Tuner

  1. Open \/ModusToolbox/tools_2.0/capsense-configurator/capsense-tuner to run the CapSense Tuner application.

  2. Select File > Open and open the design.cycapsense file in the example directory for the respective kit, in /CUSTOM_BSP_DESIGN_MODUS/TARGET_\/design.cycapsense.

  3. Switch the kit from DAPLink mode to KitProg3 mode. See Firmware-loader to learn on how to update the firmware and switch to KitProg3 mode.

  4. In the Tuner application, click Tuner Communication Setup or select Tools > Tuner Communication Setup. In the window that appears, select the I2C checkbox under KitProg3 and configure as follows:

    I2C Address: 8
    Sub-address: 2-Bytes
    Speed (kHz): 400
  5. Click Connect or select Communication > Connect.

  6. Click Start or select Communication > Start.

Under the Widget View tab, you can see the corresponding widgets highlighted in blue color when you touch the button or slider. You can also view the sensor data in the Graph View tab. For example, to view the sensor data for Button 0, select Button0_Rx0 under Button0.

Figure 1 shows the CapSense Tuner displaying the status of CapSense touch on Button0 and LinearSlider0.

Figure 1. CapSense Tuner Showing Touch Data

See the ModusToolbox CapSense Tuner Guide (Help > View Help) for more information.

Design and Implementation

In this project, PSoC 6 MCU scans a self-capacitance (CSD) based, 5-element CapSense slider and two mutual capacitance (CSX) CapSense buttons for user input. The project uses the CapSense middleware; see ModusToolbox User Guide for details on selecting the middleware. See AN85951 – PSoC 4 and PSoC 6 MCU CapSense Design Guide for more details of CapSense features and usage.

This example turns the User LED ON when any of the widgets is touched and OFF when none of them are touched, and prints the button status and slider position over the serial port.

This example enables CapSense Tuner communication over I2C for CapSense data monitoring. This example uses the following RTOS objects and runs a thread for periodic CapSense scan apart from the main() thread.

Semaphore: The scan loop calls acquire() to acquire a semaphore while initiating the scan. In subsequent loops, the program waits to acquire the semaphore before initiating the next scan and processes the touch information. The semaphore is released at the end of the scan callback.

EventQueue: The dispatcher of the EventQueue is run inside a thread to periodically scan the sensors.

The ModusToolbox CapSense Configurator Tool Guide describes step-by-step instructions on how to launch and use CapSense Configurator in ModusToolbox. The CapSense Configurator Tool can be launched in ModusToolbox IDE from the CSD personality, as well as in stand-alone mode.

Operation at Custom Power Supply Voltage

Table 1 lists the power supply voltages supported by each kit along with the default operating voltage.

Table 1. Operating Voltages Supported by the Kits
Kit Supported Operating Voltages Default Operating Voltage
CY8CPROTO-062-4343W 3.3 V / 1.8 V 3.3 V
CY8CKIT-062-BLE 3.3 V / 1.8 V 3.3 V
CY8CKIT-062-WIFI-BT 3.3 V / 1.8 V 3.3 V
CY8CKIT-062S2-43012 3.3 V / 1.8 V 3.3 V
CYW9P62S1-43438EVB-01 3.3 V Only 3.3 V
CYW9P62S1-43012EVB-01 1.8 V Only 1.8 V

For the kits that support multiple operating voltages, do the following to work at a custom power supply, such as 1.8 V:

  1. Open //ModusToolbox/tools_2.0/device-configurator/device-configurator to run the Device Configurator tool.

  2. Select File > Open. Navigate to and open design.modus file for the respective kit: \/TARGET_\/CUSTOM_BSP_DESIGN_MODUS/design.modus.

  3. Update the operating conditions as shown in Figure 2 and select File > Save.

##### Figure 2. Power Settings to Work with 1.8 V

  1. Change the jumper/switch setting as listed in Table 2.

##### Table 2. Jumper/Switch Position for 1.8 V Operation

Kit Jumper/Switch Position
CY8CPROTO-062-4343W J3 (1-2)
CY8CKIT-062-BLE SW5 (1-2)
CY8CKIT-062-WIFI-BT SW5 (1-2)
CY8CKIT-062S2-43012 J14 (1-2)
  1. Re-build and program the application to evaluate the application at the new power setting.

Creating Custom Device Configurations

The code example overrides the default device configuration provided in /mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/TARGET_\/COMPONENT_BSP_DESIGN_MODUS with the one provided in /COMPONENT_CUSTOM_DESIGN_MODUS/TARGET_\ for the supported kits. The custom configuration has source files (cycfg_capsense.c/.h) generated using the CapSense Configurator. The CapSense middleware requires these files. The default configurations that ship with Mbed OS do not contain these files. You can create a custom configuration for a new kit by following the steps below.

  1. Create a new directory inside COMPONENT_CUSTOM_DESIGN_MODUS with the same name as the target you are building the example for, such as /COMPONENT_CUSTOM_DESIGN_MODUS/TARGET_\.

  2. Copy the contents of the folder COMPONENT_BSP_DESIGN_MODUS at /mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/TARGET_\/COMPONENT_BSP_DESIGN_MODUS into the folder created in the above step except the GeneratedSource folder.

Note: The files design.cycapsense and design.qspi are copied so that you don’t have to configure these peripherals again. All you have to do is to enable these peripherals in design.modus to use them.

  1. Open the copied design.modus using Device Configurator. You will be prompted to provide a path to the device support library as shown in Figure 3.

##### Figure 3. Prompt for Device Support Library Path

  1. Click OK and provide the path to the device support library in mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/psoc6pdl/devicesupport.xml as shown in Figure 4.

##### Figure 4. Select devicesupport.xml

  1. The default configuration does not enable EZI2C peripheral for the device. The EZI2C peripheral communicates with CapSense Tuner. Select the SCB whose pins are connected to the KitProg I2C lines by referring to the schematic. Enable the SCB as an EZI2C peripheral from the Personality drop-down menu and configure as shown in Figure 5. Since same set of I2C pins can be supported by multiple SCBs, select the SCB that can wake-up the device from deep sleep for the pins that are connected to the I2C lines of KitProg. In Figure 5, SCB8 is selected.

##### Figure 5. Configure EZI2C

Note: If the SCB block is not deep sleep wake-up capable, use sleep_manager_lock_deep_sleep() in main to prevent the device from entering deep sleep when using CapSense Tuner.

For example, CYW9P62S1-43012EVB-01 has the I2C lines connected to P1[0] and P1[1] which are not associated with a deep sleep wake-up capable SCB.

  1. In the Pins tab, provide aliases to the EZI2C pins as shown in Figure 6.

##### Figure 6. Configure EI2C Pins

  1. In the Peripheral Clocks tab, provide an alias to the EZI2C peripheral clock divider as shown in Figure 7.

##### Figure 7. Configure EZI2C Peripheral Clock Divider

  1. Save the file to generate the source files.

  2. Disable the default configuration in /mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/TARGET_\/COMPONENT_BSP_DESIGN_MODUS and enable the custom configuration in /COMPONENT_CUSTOM_DESIGN_MODUS/TARGET_\ by making the following changes in mbed_app.json:
    "<kit>": { "target.components_remove": ["BSP_DESIGN_MODUS"], "target.components_add":["CUSTOM_DESIGN_MODUS"] }

Related Resources

Application Notes
AN228571 – Getting Started with PSoC 6 MCU on ModusToolbox Describes PSoC 6 MCU devices and how to build your first application with ModusToolbox
AN221774 – Getting Started with PSoC 6 MCU on PSoC Creator Describes PSoC 6 MCU devices and how to build your first application with PSoC Creator
AN210781 – Getting Started with PSoC 6 MCU with Bluetooth Low Energy (BLE) Connectivity on PSoC Creator Describes PSoC 6 MCU with BLE Connectivity devices and how to build your first application with PSoC Creator
AN85951 – PSoC 4 and PSoC 6 MCU CapSense Design Guide The PSoC 4 and PSoC 6 MCU CapSense Design Guide shows how to design capacitive touch sensing applications with the PSoC 4, PSoC 6 families of devices
Code Examples
Using Mbed OS
Using ModusToolbox IDE Using PSoC Creator
Device Documentation
PSoC 6 MCU Datasheets PSoC 6 Technical Reference Manuals
Development Kits Buy at
CY8CKIT-062-BLE PSoC 6 BLE Pioneer Kit CY8CKIT-062-WiFi-BT PSoC 6 WiFi-BT Pioneer Kit
CY8CPROTO-063-BLE PSoC 6 BLE Prototyping Kit CY8CPROTO-062-4343W PSoC 6 Wi-Fi BT Prototyping Kit
CY8CKIT-062S2-43012 PSoC 62S2 Wi-Fi BT Pioneer Kit
PSoC 6 Peripheral Driver Library and docs psoc6pdl on GitHub
Cypress Hardware Abstraction Layer Library and docs psoc6hal on GitHub
CapSense library and docs capsense on GitHub
Links to all PSoC 6 Middleware psoc6-middleware on GitHub
ModusToolbox IDE The Cypress IDE for PSoC 6 and IoT designers
PSoC Creator The Cypress IDE for PSoC and FM0+ development

Other Resources

Cypress provides a wealth of data at to help you select the right device, and quickly and effectively integrate it into your design.

For PSoC 6 MCU devices, see How to Design with PSoC 6 MCU - KBA223067 in the Cypress community.

Document History

Document Title: CE226594 - PSoC 6 MCU: CapSense Buttons and Slider

Version Description of Change
1.0.0 Initial release.
Tested with mbed-os v5.11.4 and CapSense middleware v1.2
1.1.0 Minor update.
Tested with mbed-os v5.13.1 and CapSense middleware v2.0
1.2.0 Updated to work with CapSense Tuner in ModusToolbox 1.1
Tested with mbed-os v5.14 and CapSense middleware v2.0
1.3.0 Updated to work with CapSense Tuner in ModusToolbox 2.0
Tested with mbed-os v5.14.1 and CapSense middleware v2.0
Updated Monitor data using CapSense Tuner section
Added Operation at custom power supply section
Added Design and Implementation section
1.4.0 Readme updates.
Re-structured custom TARGET folders
Added support for CYW9P62S1-43438EVB-01 and CYW9P62S1-43012EVB-01
Added deep sleep callbacks for supporting tickless operation
Tested with mbed-os v5.15.1 and CapSense middleware v2.0
This update is not backward compatible with Mbed OS versions < 5.15.1

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