Retrieve Touch Data

This section describes how to retrieve an instant of touch data from the IC. This includes touch coordinates, finger events, and other fixed data. Refer to the table below for details.

Reading the touch data when no interrupt has been raised (i.e., interrupt signal remains high), may result in the freeze of the touch controller.

The recommended procedure is thus:

• First, check the Interrupt signal is low.
• If so, then read the touch data.
• Optionally, check the CRC of the data read.
• Check the touch data is valid. Content at address 0x03 bits 1:0 should be inferior to 0x0f.
• If so, record the event and calculate the x and y coordinates based on the table below.

Take note of the following maximum values for the coordinates when mapping data points.

These correspond with the resolution of a 3.7” EPD.

X-coordinate	239
Y-coordinate	415