66.6.15.8 Measured Values, Registers and Flags

As soon as the controller finishes the Touchscreen sequence, XRDY, YRDY and PRDY are set and can generate an interrupt. These flags can be read in the Interrupt Status register (ADC_ISR). They are reset independently by reading in the ADC Touchscreen X Position register (ADC_XPOSR), the ADC Touchscreen Y Position register (ADC_YPOSR) and the ADC Touchscreen Pressure register (ADC_PRESSR).

ADC_XPOSR presents XPOS (VX - VXmin) on its LSB and XSCALE (VXMAX - VXmin) aligned on the 16th bit.

ADC_YPOSR presents YPOS (VY - VYmin) on its LSB and YSCALE (VYMAX - VYmin) aligned on the 16th bit.

To improve the quality of the measure, the user must calculate XPOS/XSCALE and YPOS/YSCALE.

VXMAX, VXmin, VYMAX, and VYmin are measured at the first startup of the controller. These values can change during use, so it can be necessary to refresh them. Refresh can be done by writing ‘1’ in the ADC_CR.TSCALIB field.

ADC_PRESSR presents Z1 on its LSB and Z2 aligned on the 16th bit. See 4-wire Pressure Measurement Method.