AT42QT2640_14 Datasheet, PDF (34/73 Pages) ATMEL Corporation – 64-key 8-slider/wheel QMatrix FMEA

4.7 Addresses 15 to 22 – Slider Positions
Table 4-6. Slider Touch Positions
Address
Bit 7
Bit 6
Bit 5
15
16
17
18
19
20
21
22
Bit 4
Bit 3
Slider 0
Slider 1
Slider 2
Slider 3
Slider 4
Slider 5
Slider 6
Slider 7
Bit 2
Bit 1
Bit 0
Each address reports the touch position for one slider/wheel, to 8-bit resolution, as an unsigned integer. Each
address is updated only when the corresponding slider/wheel is touched and the relevant bit in the Slider Detect
Status byte is set. After touch is removed from a slider/wheel, the value reported will remain at the last known touch
position.
A change in this value will cause the CHANGE line to be asserted. The CHANGE pin becomes inactive on reading
address 6, so its important to read addresses 6 through 22 in one operation to ensure a valid set of data is collected
and no changes are missed.
4.8 Address 23 – Frequency Hop Mode
The value in this address is a copy of the FHM Setup.
4.9 Address 24 – Current Frequency
When FHM = 1 or FHM = 2, the frequency hopping module switches between three configurable frequencies. This
byte indicates which of the three frequency selections is currently in use.
Table 4-7. Current Frequency
Value
0
1
2
Description
Configured frequency 0 (FREQ0) is in use
Configured frequency 0 (FREQ1) is in use
Configured frequency 0 (FREQ2) is in use
4.10
Address 25 – Current Pulse Spacing
The burst sampling frequency is changed by using different idle times, or pulse spacing, between consecutive pulses
in the burst. This byte reflects that idle time, with each increment representing an increase of approximately 188ns.
AT42QT2640 [PRELIMINARY DATASHEET]
34
9684DX–AT42–12/13