Addressing Multiple CY8CMBR3xxx CapSense® Express™ Devices on the Same I2C Bus – KBA90792

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    Version: *A


    Question: How can you address multiple CY8CMBR3xxx CapSense® Express™ family devices on the same I2C bus?



    By default, all I2C addresses of CY8CMBR3xxx CapSense Express devices are set to 0x37. You can use one of the following methods to enable addressing multiple devices on the same I2C bus:

    Method 1 (Applicable for all parts in the CY8CMBR3xxx family):

    Configure CapSense Express controllers with different I2C addresses by using the production programmer before assembly.

    Method 2 (Applicable only for parts that have the XRES input):

    If configuring the CapSense Express Controller is performed by the Host Controller after the assembly, perform the following sequence of tasks from the Master Controller. You perform these steps on one device at a time.

    1.   Put CE#1 in reset mode by pulling the XRES pin LOW for all devices with the same I2C address, except the one you are configuring. This is applicable if there are more than two CapSense Express devices with the same address on the bus.
    2.   Send the configuration file generated by the EZ-Click™ Customizer tool to CE#2 over the I2C bus. The configuration file must have different addresses for CE#1 and CE#2 in EZ-Click to avoid address conflicts.
    3.   Reset CE#2 for the configuration to take effect. This can be a software reset or a hardware reset.
    4.   Configure CE#1.