PSoC™ 4: GPIO pins

This example demonstrates multiple methods of configuring, reading, writing, and generating interrupts with PSoC™ 4 general purpose input/output (GPIO) pins. See AN86439 - PSoC™ 4 - using GPIO pins for an overview of GPIO basics, configuration options, mixed-signal use, interrupts, and low-power behavior.

View this README on GitHub.

Provide feedback on this code example.

Requirements

ModusToolbox™ software v3.0 or later (tested with v3.0)

Note: This code example version requires ModusToolbox™ software v3.0 or later and is not backward compatible with v2.4 or any older versions.
Board support package (BSP) minimum required version: 3.0.0
Programming language: C
Associated parts: PSoC™ 4000S, PSoC™ 4100S, PSoC™ 4100S Plus, PSoC™ 4500S, and PSoC™ 4100S Max

Supported toolchains (make variable 'TOOLCHAIN')

GNU Arm® embedded compiler v10.3.1 (GCC_ARM) - Default value of TOOLCHAIN
Arm® compiler v6.16 (ARM)
IAR C/C++ compiler v9.30.1 (IAR)

Supported kits (make variable 'TARGET')

PSoC™ 4100S Max pioneer kit (CY8CKIT-041S-MAX) - Default value of TARGET
PSoC™ 4100S Plus prototyping kit (CY8CKIT-149)
PSoC™ 4000S CAPSENSE™ prototyping kit (CY8CKIT-145-40XX)
PSoC™ 4100S CAPSENSE™ pioneer kit (CY8CKIT-041-41XX)
PSoC™ 4500S pioneer kit (CY8CKIT-045S)

Hardware setup

This example uses the board's default configuration. See the kit user guide to ensure that the board is configured correctly.

Note: The PSoC™ 4 kits ship with KitProg2 installed. The 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 If you do not upgrade, you will see an error like "unable to find CMSIS-DAP device" or "KitProg firmware is out of date".

Use jumper wire to externally connect the reference pin (P2[0]) to either logic HIGH (3V3) or logic LOW (GND).

Software setup

This example requires no additional software or tools.

Using the code example

Create the project and open it using one of the following:

In Eclipse IDE for ModusToolbox™ software

Click the New Application link in the Quick Panel (or, use File > New > ModusToolbox™ Application). This launches the Project Creator tool.
Pick a kit supported by the code example from the list shown in the Project Creator - Choose Board Support Package (BSP) dialog.

When you select a supported kit, the example is reconfigured automatically to work with the kit. To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can use the Library Manager to select or update the BSP and firmware libraries used in this application. To access the Library Manager, click the link from the Quick Panel.

You can also just start the application creation process again and select a different kit.

If you want to use the application for a kit not listed here, you may need to update the source files. If the kit does not have the required resources, the application may not work.
In the Project Creator - Select Application dialog, choose the example by enabling the checkbox.
(Optional) Change the suggested New Application Name.
The Application(s) Root Path defaults to the Eclipse workspace, which is usually the desired location for the application. If you want to store the application in a different location, you can change the Application(s) Root Path value. Applications that share libraries should be in the same root path.
Click Create to complete the application creation process.

For more details, see the Eclipse IDE for ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mt_ide_user_guide.pdf).

In command-line interface (CLI)

ModusToolbox™ software provides the Project Creator as both a GUI tool and the command line tool, "project-creator-cli". The CLI tool can be used to create applications from a CLI terminal or from within batch files or shell scripts. This tool is available in the {ModusToolbox™ software install directory}/tools_{version}/project-creator/ directory.

Use a CLI terminal to invoke the "project-creator-cli" tool. On Windows, use the command line "modus-shell" program provided in the ModusToolbox™ software installation instead of a standard Windows command-line application. This shell provides access to all ModusToolbox™ software tools. You can access it by typing modus-shell in the search box in the Windows menu. In Linux and macOS, you can use any terminal application.

The "project-creator-cli" tool has the following arguments:

Argument	Description	Required/optional
`--board-id`	Defined in the `<id>` field of the BSP manifest	Required
`--app-id`	Defined in the `<id>` field of the CE manifest	Required
`--target-dir`	Specify the directory in which the application is to be created if you prefer not to use the default current working directory	Optional
`--user-app-name`	Specify the name of the application if you prefer to have a name other than the example's default name	Optional

The following example clones the "mtb-example-psoc4-gpio" application with the desired name "MyGPIO" configured for the CY8CKIT-149 BSP into the specified working directory, C:/mtb_projects:

project-creator-cli --board-id CY8CKIT-149 --app-id mtb-example-psoc4-gpio --user-app-name MyGPIO --target-dir "C:/mtb_projects"

Note: The project-creator-cli tool uses the git clone and make getlibs commands to fetch the repository and import the required libraries. For details, see the "Project creator tools" section of the ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).

To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can invoke the Library Manager GUI tool from the terminal using make library-manager command or use the Library Manager CLI tool "library-manager-cli" to change the BSP.

The "library-manager-cli" tool has the following arguments:

Argument	Description	Required/optional
`--add-bsp-name`	Name of the BSP that should be added to the application	Required
`--set-active-bsp`	Name of the BSP that should be as active BSP for the application	Required
`--add-bsp-version`	Specify the version of the BSP that should be added to the application if you do not wish to use the latest from manifest	Optional
`--add-bsp-location`	Specify the location of the BSP (local/shared) if you prefer to add the BSP in a shared path	Optional

Following example adds the CY8CKIT-041S-MAX BSP to the already created application and makes it the active BSP for the app:

library-manager-cli --project "C:/mtb_projects/MyGPIO" --add-bsp-name CY8CKIT-041S-MAX --add-bsp-version "latest-v3.X" --add-bsp-location "local"

library-manager-cli --project "C:/mtb_projects/MyGPIO" --set-active-bsp APP_CY8CKIT-041S-MAX

In third-party IDEs

Use one of the following options:

Use the standalone Project Creator tool:
1. Launch Project Creator from the Windows start menu or from {ModusToolbox™ software install directory}/tools_{version}/project-creator/project-creator.exe.
2. In the initial Choose Board Support Package screen, select the BSP, and click Next.
3. In the Select Application screen, select the appropriate IDE from the Target IDE drop-down menu.
4. Click Create and follow the instructions printed in the bottom pane to import or open the exported project in the respective IDE.

Use command-line interface (CLI):
1. Follow the instructions from the In command-line interface (CLI) section to create the application.
2. Export the application to a supported IDE using the make <ide> command.
3. Follow the instructions displayed in the terminal to create or import the application as an IDE project.

For a list of supported IDEs and more details, see the "Exporting to IDEs" section of the ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).

Operation

Connect the Reference pin (P2.0) to logic LOW externally using a jumper wire.
Connect the board to your PC using the provided USB cable through the KitProg3 USB connector.
Program the board using one of the following:
Using Eclipse IDE for ModusToolbox™ software
1. Select the application project in the Project Explorer.
2. In the Quick Panel, scroll down, and click <Application Name> Program (KitProg3_MiniProg4).
Using CLI

From the terminal, execute the make program command to build and program the application using the default toolchain to the default target. The default toolchain is specified in the application's Makefile but you can override this value manually:
```
make program TOOLCHAIN=<toolchain>
```
Example:
```
make program TOOLCHAIN=GCC_ARM
```
After programming, the application starts automatically.
Confirm that the user LED toggles thrice.
Connect the Reference pin (P2.0) to logic HIGH externally using a jumper wire. Press the user button to observe the change in the state of the user LED. When the user button is pressed, the state of the Reference pin is read and then written to the user LED using the Cy_GPIO_Write() PDL API.
Now connect the Reference pin (P2.0) to logic LOW. Press the user button to observe the change in the state of the user LED.

The value on port 4 pins are incremented continuosly and the toggling port pins can be monitored on an oscilloscope.

Debugging

You can debug the example to step through the code. In the IDE, use the <Application Name> Debug (KitProg3_MiniProg4) configuration in the Quick Panel. For details, see the "Program and debug" section in the Eclipse IDE for ModusToolbox™ software user guide.

Design and implementation

This example demonstrates the GPIO pin configuration, reading, writing, full port access, and interrupts using multiple GPIO PDL driver methods. Use the GPIO PDL driver method suitable for your application. See the comments in the main.c file or the AN86439 - PSoC™ 4 - using GPIO pins for more details on each PDL driver method.

To demonstrate individual GPIO pin access, this example reads the value from the Reference pin and writes it to the user LED. The user LED toggles twice to demonstrate the set/clear function.

The user button is configured to generate an interrupt on a falling edge, which occurs on a button release. The interrupt routine reads the value from the Reference pin and writes to the user LED.

A full port of GPIO pins is configured as output pins on port 4. The value on port 4 is continuously read with direct register reads, incremented, and written back to the port. The toggling port pins can be monitored on an oscilloscope.

Resources and settings

Table 1. Application resources

Resource	Alias/object	Purpose
GPIO (BSP)	CYBSP_USER_LED	User LED to show the output
GPIO (BSP)	CYBSP_USER_BUTTON	User button to generate the interrupt
GPIO (BSP)	CYBSP_REFERENCE_PIN	Reference pin to update the state of user LED
GPIO (BSP)	Port 4	GPIO pins to show Port access

Related resources

Resources	Links
Application notes	AN79953 – Getting started with PSoC™ 4 AN85951 – PSoC™ 4 and PSoC™ 6 MCU CAPSENSE™ design guide AN86439 - PSoC™ 4 using GPIO Pins
Code examples	Using ModusToolbox™ software on GitHub Using PSoC™ Creator
Device documentation	Download datasheets, TRMs, and more from the PSoC™ 4 product page
Development kits	Select your kits from the Evaluation Board Finder page.
Libraries on GitHub	mtb-pdl-cat2 – PSoC™ 4 peripheral driver library (PDL) mtb-hal-cat2 – Hardware abstraction layer (HAL) library
Tools	ModusToolbox™ software – ModusToolbox™ software is a collection of easy-to-use software and tools enabling rapid development with Infineon MCUs, covering applications from embedded sense and control to wireless and cloud-connected systems using AIROC™ Wi-Fi and Bluetooth® connectivity devices. PSoC™ Creator – IDE for PSoC™ and FM0+ MCU development

Other resources

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

Document history

Document title: CE231471 - PSoC™ 4: GPIO pins

Version	Description of change
1.0.0	New code example. This version is not backward compatible with ModusToolbox™ software v2.3.
2.0.0	Major update to support ModusToolbox™ v3.0. This version is not backward compatible with the previous versions of ModusToolbox™ software.

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