features depend on the filter capacitor used in the touch screen pins (X+, Y+, X-, Y-). For small screens, less than 6, a filter capacitor of 1-2nF is recommended to be placed in each of the touchscreen pins, while for bigger screens, 5-10nF capacitors can be used.In case of 1-2nF capacitors: 500uS settling time and touch detect delay are recommended.In case of 5-10nF capacitors:1mS settling time and touch detect delay are recommended.In this document, 2nF filter is assumed. Hence 500uS settling time and 500uS Touch Detect Delay are used.b) Average control: average of 2 or 4 is recommended. In this document, 4 point averaging is used. Write 0x9A to this register for the above mentioned setting.AN2807Device initialization 3/117. FIFO_TH (0x4A), to set FIFO threshold level.FIFO threshold defines the minimum number of samples in the FIFO memory before it gives interrupt. The setting depends on the interrupt handling architecture to be used. Refer to Section1.1. In overall there are two op datasheet.www.st.comDevice initializationAN28072/11 1 Device initializationIn the startup of the system, the initialization of each hardware is performed. For STMPE811 operating as touchscreen controller, the registers listed below need to be initialized:1.SYS_CTRL_2 register (0x04), to turn on the necessary blocks. To turn on the touchscreen controller block, we need to turn on both the touchscreen controller and ADC blocks by writing 0x0C to this register.2. INT_EN register (0x0A), to enable the required interrupt source.For the touchscreen function, only three interrupt sources need to be enabled: TOUCH_DETECT and FIFO_TH. - Write 0x03 to this register for group data reading. - Write 0x02 to this register for single data reading.3. ADC_CTRL1 (0x20), to select sample time, bit number and ADC reference.a) Sample time: it is recommended to select 80 clock cycles for ADC conversion in order to get reasonably fast data rate and accurate reading.b) ADC bit number: 12-bit ADC is used in th September 2008 Rev 11/11AN2807STMPE811 referen