PSoC™ 4: Basic LIN slave example in MTB

This code example shows how to implement a basic LIN 2.2 slave using the LIN Middleware in PSoC™ 4. PSoC™ 4 responds to an external LIN Master's commands to:

1. Turn on the corresponding color LED on PSoC™ development kit
2. Report the current LED color status

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 version 3.0 or later and is not backward compatible with v2.4 or older versions.

• Board support package (BSP) minimum required version: 3.0.0

• Programming language: C

• Associated parts: PSoC™ 4100S

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 CAPSENSE™ pioneer kit (CY8CKIT-041-41XX) - Default value of TARGET

A LIN transceiver is not available on the standard PSoC™ development kits. Hence, this application needs CAN and LIN Shield Kit (CY8CKIT-026) as a compatible shield kit to connect the LIN Tx and Rx signals from the PSoC™ to a LIN bus or an analyzer.

Hardware setup

Note: Some of 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 If you do not upgrade, you will see an error like "unable to find CMSIS-DAP device" or "KitProg firmware is out of date".

The hardware setup block diagram and connections are shown in Figure 1; detailed hardware connections are explained below.

Figure 1. LIN slave communication hardware setup

Note: The CY8CKIT-41-41XX kit comes with an enclosure for a CAPSENSE™ trackpad. The enclosure should be opened and the Arduino headers available in the kit box should be mounted into respective headers.

Figure 2 shows the hardware setup using CY8CKIT-041-41XX and CY8CKIT-026.

Figure 2. Hardware setup using CY8CKIT-041-41XX and CY8CKIT-026

Follow these instructions to set up the hardware:

1. Because there are two LIN transceivers on CY8CKIT-026, choose either of the transceivers to use (U5 – LIN1 transceiver or U3 – LIN2 transceiver). Connect the Arduino header pins (which are connected to the base board controller) to the appropriate LIN transceiver using jumper wires as shown in Table 1.

Table 1. Pin connections on CY8CKIT-026

Arduino header pins	LIN1 transceiver	LIN2 transceiver
J3_SCL	J15_1 (LIN1_RX)	J6_1 (LIN2_RX)
J3_SDA	J15_2 (LIN1_TX)	J6_2 (LIN2_TX)
J2_6	J15_3 (LIN1_NSLP)	J6_3 (LIN2_NSLP)

2. Make sure that jumper J16 (if the LIN1 transceiver is being used) is shorted or jumper J7 (if the LIN2 transceiver is being used) is shorted.

Note: This is to provide a 12 V supply to the Silicon Engines LIN-USB analyzer; if any other analyzer is being used, then follow the instructions for power supply requirements and short the jumper only if it requires a 12 V supply.

3. The baseboard (PSoC™ 4 kit) can be powered using USB or it can be powered from the Shield kit by selecting jumper J20 appropriately as shown in Table 2. See the CY8CKIT-026 user guide for more details.

Table 2. Powering options with jumper (J20)

J20 connection	Power option	Baseboard (CY8CKIT-041-41XX) requirement
Short pin 2 and 3	Power baseboard using Shield Kit with 5 V	Baseboard power selection jumper (J10 on CY8CKIT-041-41XX) should be at 3.3 V (only if USB is not connected to the baseboard).
Short pin 3 and 4	Power baseboard using Shield Kit with 12 V	Baseboard power selection jumper (J9 on CY8CKIT-041-41XX) should be at 3.3 V (only if USB is not connected to the baseboard).

Note: If the baseboard is powered through USB, and a 12 V supply is connected to the Shield Kit, the position of the power jumper selection (J20) is not significant.

4. Verify switch configurations on the baseboard as below Table 3:

Table 3. Switch configurations on CY8CKIT-041-41XX

Switch number	Position	Comment
SW4	VREG/VBUS	Power PSoC™ using on-board regulator or directly through Vbus
SW5	POS 1	Connect SWD pins from KitProg to PSoC™ 4100S
SW6	POS3 (5.0V)	Configure PSoC™ MCU's Vdd to be 5V. It should be set to 3.3V when baseboard is powered by 5V/12V from the Shield kit
SW7	Only P5 is ON	No power monitoring required

5. Plug in CY8CKIT-026 to CY8CKIT-041-41XX through the Arduino-compatible connectors.

6. Connect the LIN analyzer to the J14 connector to use LIN1 transceiver or J5 connector to use LIN2 transceiver.

Warning: Be careful to not power up the Shield Kit with multiple supplies.

7. If the LIN analyzer DOES NOT provide 12 V to the VBAT pin, connect a 12 V supply to CY8CKIT-026 through the J11 power jack or J12 screw terminal connector.

8. If the LIN analyzer DOES provide 12 V to the VBAT pin, the Shield kit can be powered from the LIN analyzer if desired without an external 12 V supply. For that configuration, the J16 jumper (for LIN1 transceiver) or the J7 jumper (LIN2 transceiver) should be placed.

Note: The Silicon Engines LIN-USB analyzer requires a 12 V input supply, so either J16 (for LIN1) or J7 (for LIN2) must be placed and an external 12 V supply must be provided to J11 power jack or J12 screw terminal connector.

Software setup

Install the LIN analyzer’s corresponding PC software. In this code example, we have used LIN/USB Message Center software.

Using the code example

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

In Eclipse IDE for ModusToolbox™ software

1. Click the New Application link in the Quick Panel (or, use File > New > ModusToolbox™ Application). This launches the Project Creator tool.

2. 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.

3. In the Project Creator - Select Application dialog, choose the example by enabling the checkbox.

4. (Optional) Change the suggested New Application Name.

5. 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.

6. 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.

Alternatively, you can manually create the application using the following steps:

1. Download and unzip this repository onto your local machine, or clone the repository.

2. Open a CLI terminal and navigate to the application folder.

   On Windows, use the command line modus-shell program provided in the ModusToolbox™ installation instead of a standard Windows command line application. This shell provides access to all ModusToolbox™ 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.

   Note: The cloned application contains a default BSP file (TARGET_xxx.mtb) in the deps folder. Use the Library Manager (make modlibs command) to select and download a different BSP file, if required. If the selected kit does not have the required resources or is not supported, the application may not work.

3. Import the required libraries by executing the make getlibs command.

Various CLI tools include a -h option that prints help information to the terminal screen about that tool. For more details, see the ModusToolbox™ User Guide (locally available at {ModusToolbox install directory}/docs_{version}/mtb_user_guide.pdf).

In third-party IDEs

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.

Operation

To test the project, a “Silicon Engines LIN-USB Converter – Model 9011” is used as LIN analyzer. Other LIN analyzers may also be used.

Follow these steps to test the project:

1. Make the hardware connections as described in the Hardware Setup section.

2. Program the baseboard (CY8CKIT-041-41XX) using one of the following:

   Using Eclipse IDE for ModusToolbox™

   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
   

4. Install the ‘SE9004 and 9011 LINUSB Message Center’ software (if a different analyzer is being used, install the appropriate software) on your PC.

5. Connect the LIN analyzer to a PC through a USB cable and open the LIN analyzer software in PC.

6. On the LIN analyzer software, go to Configure LIN/USB. The Configure LIN Box Interface window is displayed. Set the LIN Bus Baud Rate to 19200 bps, and then select the LIN 2.0-2.1 Protocol checkbox, as shown in Figure 3.

Figure 3. LIN analyzer configurations

7. If you are using any other analyzer, make sure that the checksum setting is selected as enhanced checksum since LIN v2.1/2.2 specification supports only enhanced checksum (this option is not required in Silicon Engines LIN-USB converter software).

8. Add the message in the analyzer software that should be transmitted to the slave and send it through the analyzer, as shown in Figure 4, Note that the message must start with the ID.

Figure 4. Adding and sending message using LIN analyzer

9. If a frame with ID = 0x10 is received from the master (analyzer), the slave controls the baseboard LEDs based on the received data command from the master as shown in Table 4. Note that the message must start with the ID and must contain eight data bytes even though only the first byte is used to control the LEDs. The other seven data bytes can be any value.

Table 4. Slave response per commands from master

Command	Slave response
0x11	Turns on LED1 (Red LED)
0x22	Turns on LED2 (Green LED)
0x33	Turns on LED3 (Blue LED)
0x00	Turns off all LEDs

10. If a frame with ID = 0x11 is received from the master (analyzer), then the slave sends the status of baseboard LEDs back to the master as shown in Table 5. The message in this case only needs the message ID. No data bytes are required.

Table 5. LED status

LED status on PSoC™ kit	Data byte
LED1 (Red LED) on	0xAA
LED2 (Green LED) on	0xBB
LED3 (Blue LED) on	0xCC
All LEDs off	0xDD

Note: In this example, PSoC™ 4 (LIN Slave) sends the status of previously received command as the first byte and the current status of LEDs as the second byte.

11. The result of transmitted and received data at the LIN analyzer is shown in Figure 5.

Figure 5. Results at LIN analyzer

In this figure, InFrame refers to “10 22 FF FF FF FF FF FF FF” where 10 is the frame ID and 22, FF, FF, FF, FF, FF, FF, FF are the eight data bytes. As PSoC™ 4 needs only the first data byte for the command, remaining bytes can be ignored. When the 'OutFrame' is received from the analyzer (LIN Master) as marked in this figure, the slave responds to the frame with the current LED status along with the frame ID and previously received command as “11 22 BB” where '11' is frame ID, '22' is the previous 'InFrame' data byte (command) and 'BB' is the LED status (i.e., LED2 is ON).

Note: If there is an error message such as “BUS STUCK HIGH” or “TX FRAME ERROR”, reset the baseboard (CY8CKIT-041-41XX) and LIN analyzer.

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

The following screenshots show the parameter settings for the LIN configurator. Only the parameters that vary from their default values are shown.

Figure 6 shows the Frames tab settings for the LIN configurator. Use this tab to add a new frame or delete an existing frame from the LIN slave. Click the ‘Add’ button to add a new frame. For this example, three frames named “InFrame”, “OutFrame”, and “ErrorSignalFrame” are used as shown in Figure 6.

InFrame: The frame ID value is 0x10, the direction of the frame is ‘Subscribe’ and the frame type is ‘Unconditional’. OutFrame: The frame ID value is 0x11, the direction of the frame is ‘Publish’ and the frame type is ‘Unconditional’. ErrorSignalFrame: The frame ID value is 0x12, the direction of the frame is ‘Publish’ and the frame type is ‘Unconditional’.

Note: If the direction (publish/subscribe) is set as ‘Publish’, the slave responds to master; if the direction is set as ‘Subscribe’, the slave uses the received data from the master for its application.

Figure 6. LIN Configurator Frames tab settings

Figure 7 shows the Signals tab settings of the LIN Configurator. Click the ‘+’ button to add new signals and select the signal properties such as signal name, type, length and initial value. Place the signals to the corresponding frames as shown below.

Figure 7. LIN Configurator Signals tab settings

All other configuration settings are left at their default settings.

Resources and settings

Table 6 lists some of the ModusToolbox™ resources used in the example, and how they are used in the design. The design.modus file contains all the configuration settings. For example, for pin usage and configuration, open the Pins tab of the design file.

Table 6. ModusToolbox™ resources

Resource	Alias/object	purpose
SCB (LIN Middleware)	LIN	Provide communication between the LIN Master (external analyzer) and the Slave
GPIO (LIN Middleware)	LIN_TX_PIN, LIN_RX_PIN	LIN Slave controller pins
GPIO (HAL)	LED1_PIN, LED2_PIN, LED3_PIN	LED pins on CY8CKIT-041-41XX Kit

Related resources

Resources	Links
Application notes	AN79953 – Getting started with PSoC™ 4
Code examples	Using ModusToolbox™ software on GitHub Using PSoC™ Creator
Device documentation	PSoC™ 4 datasheets PSoC™ 4 technical reference manuals
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
Middleware on GitHub	lin LIN library and documents
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: CE233122 - PSoC™ 4: Basic LIN slave example in MTB

Version	Description of Change
1.0.0	New code example
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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