Page tree
Skip to end of metadata
Go to start of metadata

The following are procedures to initialize a sensor for USB HID Raw mode and I2C respectively. An initialization procedure is not required when using USB HID Touch Digitizer mode.

USB HID Raw Mode

Do the following procedure to initialize a sensor over USB HID Raw mode.

  1. Power on the sensor.
  2. Wait for HID enumeration. This signals the sensor is now booted.

  3. Set the sensor to the correct Operation Mode by sending an OperationMode command to Feature Report 1. The data to send is:

    EE 12 40 02 02 00 67 0C 80 01 FF 81 01 00 82 01 00 83 01 00

    This will put the sensor in Detection Mode (which will produce touch notifications).

  4. Wait for the sensor to signal that there is data to read. This comes as an Input Report 2.

  5. Read the data from Feature Report 2. The data should be:

    EF 12 40 02 02 00 67 0C 80 01 FF 81 01 00 82 01 00 83 01 00

    This means the mode setting has succeeded.

The initialization is now complete. After the initialization, the sensor is enabled by default and will start sending touch notifications. To disable notifications, a Disable request must be sent. Refer to ASN.1 PDU Examples in GSER Notation for examples of requests, responses and notifications.

How to communicate with the sensor is described in USB HID Transport.

I2C

Use the following procedure to initialize the sensor over I2C.

  1. Power on the sensor.
  2. Wait for sensor to assert Data Ready pin (DR).
  3. Initiate 2 byte I2C read operation. Payload of this read should be EE XX where XX is the amount of bytes to read in a second I2C read operation.
  4. Read XX amount of bytes (number of bytes to read is indicated by second byte of first I2C Read Operation). Now read a message called BootComplete. The message should be

    F0 11 40 02 00 00 63 0B 80 01 YY 81 02 03 YY 82 02 00 YY

    where YY is usually "00" but can have another value. This signals the sensor is now booted.

  5. To enable the sensor to start sending touch notifications, do the following:

    1. Sending an Enable command:

      EE 09 40 02 02 00 65 03 81 01 00
    2. Read the response. The response should be:

      EF 09 40 02 02 00 65 03 81 01 00

The initialization is now complete. When DR is asserted the sensor will send a touch notification or a new BootComplete. A BootComplete indicates that the sensor has restarted for some reason; Enable must then be set again. For more details, refer to I2C Transport.