Cypress Semiconductor / Mbed OS mbed-os-example-csdidac

This example demonstrates using the CSD current digital-to-analog converter (IDAC) as a current source and a current sink.

PSoC 6 MCU: CSDIDAC

This code example demonstrates using the CSD hardware-block-based current digital-to-analog converter (CSDIDAC) as a current source and a current sink. CSDIDAC supports two channels - A and B. Channel A is configured as a current source. The current increases when a switch is pressed. Once the output reaches its maximum value, it resets to zero and starts to increase the value again. The last current output value is maintained when the switch is not pressed. UART displays the current value for which the CSDIDAC is configured. Channel B is configured for sinking current and used for driving an LED. Firmware enables or disables the IDAC channel to toggle the LED every second. This project uses CSDIDAC Middleware Library.

Tested with Mbed OS v6.2.1

Requirements

• Programming Language: C/C++

• Associated Parts: All PSoC® 6 MCU parts

• Mbed CLI

• ModusToolbox v2.1

Note: You do not need to install ModusToolbox to build and run this code example. However, installing it is required when you need to:

• Debug using the Eclipse for ModusToolbox IDE. See the user guide for details.
• Customize the default device configuration using any of the Configurator tools
• Port this code example to a new target that is not listed under the Supported Kits

Supported Toolchains (Mbed CLI argument --toolchain)

• GNU Arm Embedded Compiler v9.2.1 (GCC_ARM)
• Arm compiler v6.14 (ARM)

Supported Kits (Mbed CLI argument --target)

• PSoC 6 Wi-Fi BT Prototyping Kit (CY8CPROTO-062-4343W)
• PSoC 6 WiFi-BT Pioneer Kit (CY8CKIT-062-WIFI-BT)
• PSoC 6 BLE Pioneer Kit (CY8CKIT-062-BLE)
• PSoC 62S2 Wi-Fi BT Pioneer Kit (CY8CKIT-062S2-43012)
• PSoC 62S1 Wi-Fi BT Pioneer Kit (CYW9P62S1-43438EVB-01)
• PSoC 62S1 Wi-Fi BT Pioneer Kit (CYW9P62S1-43012EVB-01)

Hardware Setup

This example uses the board’s default configuration. See the kit user guide to ensure that the board is configured correctly. Place a resistor across the pin mentioned in Table 1 and ground to measure the voltage across the resistor caused by the current output. To change the CSDIDAC pin, modify the CSDIDAC configuration.

Table 1. CSDIDAC Pin

Note: The PSoC 6 BLE Pioneer Kit (CY8CKIT-062-BLE) and the PSoC 6 WiFi-BT Pioneer Kit (CY8CKIT-062-WIFI-BT) 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”.

For Mbed OS, the kit must be in DAPLink mode. Refer the KitProg3 User Guide (found in the Documentation tab in the Cypress Programming Solutions web page) for details of how to put the Pioneer Kit into DAPLINK mode.

Software Setup

Install a terminal emulator if you don’t have one. Instructions in this document use Tera Term.

This example requires no additional software or tools.

Import the Code Example using Mbed CLI Tool

Mbed CLI commands are used to import the code example and compile. See Working with Mbed CLI web page.

mbed import https://github.com/cypresssemiconductorco/mbed-os-example-csdidac

It first clones the code example repository from GitHub, and then deploys all the libraries. If you wish to perform the deploy process manually, follow the below commands:

Clone the GitHub code example repository:

git clone https://github.com/cypresssemiconductorco/mbed-os-example-csdidac && cd mbed-os-example-csdidac

Deploy the dependent libraries. The library files are identified with .lib extension.

mbed deploy

Set the current directory as root:

mbed new .

Operation

1. Connect the board to your PC using the provided USB cable through the KitProg3 USB connector.

2. Program the board.

   mbed compile -m <TARGET> -t <TOOLCHAIN> --flash --sterm

   For instance, to build for the target CY8CPROTO_062_4343W with GCC_ARM toolchain, use the following command:

   mbed compile -m CY8CPROTO_062_4343W -t GCC_ARM --flash --sterm

Note: With the --sterm option, Mbed CLI opens a new 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 such as PuTTY or Tera Term.

3. After programming, the application starts automatically. Confirm that red LED toggles every second and the terminal application displays the message as shown in Figure 1.

Figure 1. Output in UART Terminal

4. Press the user button. The terminal should show the new current value for which the IDAC current source is configured, as shown in Figure 2. Calculate the current by measuring the voltage across the resistor connected between CSDIDAC pin and ground (GND). The current value should match with the value shown on the terminal.

Figure 2. Output in UART Terminal When Button Pressed

Debugging

You can debug the example to step through the code. In the IDE, use the \ Debug (KitProg3_MiniProg4) configuration in the Quick Panel. For more details, see the “Program and Debug” section in the Eclipse IDE for ModusToolbox User Guide.

Follow the steps from Eclipse IDE for ModusToolbox User Guide to export the Mbed OS code example and import it into ModusToolbox IDE for programming and debugging.

Mbed OS also supports debugging using any IDE that supports GDB. We recommend the user to go through ARM Mbed’s documentation on the debugging steps.

Note: (Only while debugging) On the CM4 CPU, some code in main() may execute before the debugger halts at the beginning of main(). This means that some code executes twice - before the debugger stops execution, and again after the debugger resets the program counter to the beginning of main(). See KBA231071 to learn about this and for the workaround.

Design and Implementation

CSDIDAC supports two channels (A and B) IDAC with 7-bit resolution. Both the channels can be independently configured for sourcing or sinking current. See CSDIDAC Middleware Library for more details. In this code example, channel A is configured for sourcing current; firmware controls the current value. Channel B is configured for sinking current and used for driving a LED. The CSDIDAC could be configured by the ModusToolbox CSD personality. Refer to the Configuration Considerations section in the API Reference Guide for configuring the CSDIDAC.

The CSDIDAC is not enabled in the default board configuration provided by the BSP. This example overrides the BSP_DESIGN_MODUS component provided with the BSP to enable and configure the CSDIDAC. See the “Overriding the BSP Configuration Files” section of the ModusToolbox User Guide: {ModusToolbox install directory}/ide_{version}/docs/mtb_user_guide.pdf

The design.modus file containing the custom device configuration used in this application is present under the respective kit’s folder: \/COMPONENT_CUSTOM_DESIGN_MODUS/TARGET_\/design.modus.

Enabling the CSDIDAC Functionality

This section guides how to set up the CSDIDAC middleware for the CSDIDAC operation using Device Configurator tool.

1. Open //ModusToolbox/tools_2.1/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. When prompted to find device support library, select the “devicesupport.xml” from \/mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/psoc6pdl/
   Note: Ensure that the command mbed deploy is executed prior to this step.

4. On the System tab, configure the CLK_PERI frequency to achieve the desired frequency. This is the clock input to the CSDIDAC.

5. On the Peripherals tab (#1 in Figure 2), enable the CSD personality under System (#2 in Figure 3) and enter the Alias (#3 in Figure 3).

6. Go to the Parameters Pane and configure the CSD personality:

7. Assign the peripheral clock divider by using the Clock combo box (#4 in Figure 3). Any free divider can be used.

8. Set the Enable CSDIDAC check box (#5 in Figure 3).

9. Configure the CSDIDAC parameters (#5 in Figure 3).

10. Assign the CSDIDAC Channels to pins (#6 in Figure 3).

11. Select File > Save to generate the initialization code. This is executed as part of the init_cycfg_all() function, which is called by cybsp_init().

    Figure 3. Settings to Enable CSDIDAC Functionality
    

Operation at a Custom Power Supply Voltage

The application is configured to work with the default operating voltage of the kit. Table 2 lists the power supply voltages supported by each kit along with the default operating voltage.

Table 2. Operating Voltages Supported by the Kits

For 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_2.1/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 3 and select File > Save.

Figure 3. Power Settings to Work with 1.8 V

4. Change the jumper/switch setting as listed in Table 3.

   Table 3. 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)
   CYW9P62S1-43438EVB-01	J14 (1-2)
   CYW9P62S1-43012EVB-01	J14 (1-2)

5. Re-build and program the application to evaluate the application at the new power setting.

Resources and Settings

The following resources are used in this example.

Table 1. Application Resources

Related Resources

Other Resources

Cypress provides a wealth of data at www.cypress.com 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: CE231012 - PSoC 6 MCU CSDIDAC

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