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USB-Serial bridge controller CY7C65211 recognized as thermometer (04b4:0002) instead of serial port in Linux - KBA236143

USB-Serial bridge controller CY7C65211 recognized as thermometer (04b4:0002) instead of serial port in Linux - KBA236143

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This error occurs because the Linux kernel which is being used has a built-in HID driver called “Cytherm” - Cypress USB thermometer driver in the kernel. Therefore, whenever you connect the CY7C65211 device, instead of binding to the Communication Device Class (CDC) Abstract Control Model (ACM) driver, it displays the device as an HID device binding to the Cytherm driver.

Infineon_Team_1-1683106073302.pngFigure 1 Error in Linux

To fix this issue when this device is being used in Linux environment, change the PID of the device using the USB-Serial Configuration Utility available in the USB-Serial Software Development Kit (SDK).

Note: USB-Serial Configuration Utility is supported only on Windows.

Do the following to change the PID for CY7C65211 using USB-Serial Configuration Utility:

  1. Open USB-Serial Configuration Utility (C:\Program Files (x86)\Cypress\USB-Serial SDK\bin\ USB Serial Configuration Utility.exe).

    Note: Only USB-Serial Configuration Utility versions and allow changing the PID for CY7C65211.
  1. Right-click the USB Serial Configuration Utility.exe file and create a shortcut to this file.
    Allow to let Windows OS to copy the shortcut to the Desktop folder. This is required only if the file explorer is opened without administrator privilege.
  1. Right-click the newly created shortcut and select Properties. Locate the target as shown in Figure 2.

    Add command line argument.png

    Figure 2 Add command line argument

  1. Add the following string in the target field and click OK. See Figure 2:
    This helps to pass the -.enablePIDChange command-line argument to the GUI utility and adds an option for changing the PID when the utility is launched.
  1. Double-click the shortcut created to launch USB-Serial Configuration Utility.
    USB-Serial Configuration Utility displays the connected USB-Serial device.
  1. On the Select Target pane, click Connect as shown in Figure 3. Note that the PID is listed as ‘0x0002’.

    USB-Serial device home page.png

    Figure 3 USB-Serial device home page

  1. Select Change PID as shown in Figure 4.

    Change the PID.png

    Figure 4 Change the PID

    Note that the PID of the device is changed from ‘0x0002’ to ‘0x00FB’.
  1. Click Program and wait for the “Program Succeed” status.
  2. Connect the device to the Linux system. Note that the device is enumerated as “Cypress Semiconductor Corp.”



    Figure 5 Enumeration in Linux