STMPE821_09 STMICROELECTRONICS [STMicroelectronics], STMPE821_09 Datasheet - Page 38

• Manufacturer Part Number: STMPE821_09
• Description: 8-channel capacitive touch key controller
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Capacitive touch module registers
CALIBRATED_IMPEDANCE
Address:
Type:
Reset:
Description:
IMPEDANCE
Address:
Type:
Reset:
Description:
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7
7
[7:0] CALIBRATED IMPEDANCE:
[7:0] IMPEDANCE:
6
6
0x70 - 0x77
R
0x00
Calibrated impedance is a reference value maintained by the device.
Calibrated reference impedance
0x80 - 0x87
R
0x00
Impedance is the instantaneous impedance value seen at the input pin of each cap.
sensing pin.
Currently sensed impedance. This impedance reading decreases with the increase of the
capacitance at sensing channel.
When this register reads 0x7F, reference capacitance should be reduced.
When this register reads 0x00, reference capacitance should be increased.
5
5
Calibrated impedance
Impedance
4
4
CAL_IMPEDANCE
IMPEDANCE
3
3
2
2
1
1
STMPE821
0
0