stmpe16m31 STMicroelectronics, stmpe16m31 Datasheet - Page 51

• Manufacturer Part Number: stmpe16m31
• Description: S-touch? 16/24-channel Touchkey Controller With Pwm And Ratio Engines
• Manufacturer: STMicroelectronics

STMPE16M31, STMPE24M31
13.4
13.5
Locked impedance
Locked impedance is data available in channel data the moment 0x06 is written into
“channel data type register”. Writing a different value into the “channel data type register”
allows the locked impedance to be refreshed.
In actual application, software writes 0x06, reads locked impedance, writes 0x00, writes
0x06, and reads the next set of data.
For data type 0x04-0x05, data are constantly being refreshed, even as it is being accessed.
If accessed slowly, the full set of data may have been sampled at significantly different time.
Calibration
Calibration event is performed in every period which is programmable from the calibration
interval register (0x76). In each calibration event, 8 impedance samples are collected and
averaged. The time period between samples is programmable from CAL_MOD (model
register (0x77).
Figure 16. Calibration
Doc ID 16174 Rev 3
Touch sensor controller
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