at42qt1060 ATMEL Corporation, at42qt1060 Datasheet - Page 20

• Manufacturer Part Number: at42qt1060
• Description: Qtouch? 6-channel Sensor Ic
• Manufacturer: ATMEL Corporation

6.10
6.11
6.12
20
Address 15: Positive Recalibration Delay
Address 16 – 21: NTHR Keys 0 – 5
Address 22: LP Mode
AT42QT1060
Table 6-10.
Table 6-11.
Table 6-12.
POSITIVE RECALIBRATION DELAY: If any key is found to have a significant drop in
capacitance, i.e. an “away from touch” signal, then this is deemed to be an error condition. If this
condition persists for more than the Positive Recalibration Delay (PRD) period, then an
automatic recalibration is carried out on all keys.
The condition that the error is triggered on depends on the drift compensation mode. If relative
referencing drifting is enabled (DRIFT = 0), then an “away from touch” delta of more than four
counts triggers the error. If only normal mode drifting is enabled (DRIFT = 1), then an “away from
touch” delta of more than 75 percent of the NTHR triggers the error.
The PRD is incremented according to the current LP mode setting (the duration is equal to the
cycle time multiplied by the PRD value).
Default: ~7 ms x 40 = 280 ms (in free-run mode)
NTHR Keys 0 – 5: these 8-bit values set the threshold value for each key to register a detection.
Default: 10 counts
LP Mode: this 8-bit value determines the number of 16 ms intervals between key
measurements. Longer intervals between measurements yield lower power consumption at the
expense of slower response to touch.
Address
Address
Address
16 – 21
15
22
Positive Recalibration Delay
NTHR Keys 0 – 5
LP Mode
MSB
MSB
b7
b7
b7
b6
b6
b6
b5
b5
b5
POSITIVE RECALIBRATION DELAY
b4
b4
b4
b3
b3
b3
b2
b2
b2
b1
b1
b1
9505E–AT42–02/09
LSB
LSB
b0
b0
b0