qt60161b Quantum Research Group, qt60161b Datasheet - Page 21

• Manufacturer Part Number: qt60161b
• Description: 16 Key Qmatrix Keypanel Sensor Ic
• Manufacturer: Quantum Research Group

5.4 Setup Commands
Setup functions are those that alter the behavior a key or a
group of keys. The setups are programmed into eeprom
locations in the part and ordinarily do not need to be
reprogrammed once set. However it is possible to change a
setup while the device is in normal operation without
interrupting the sensing function of the part.24
Setup functions alter the internal eeprom, and this requires a
much longer time to complete than other commands; see
Table 4-1.
Setup 'put' commands become effective immediately after the
echo response of the command byte unless otherwise noted;
some setups require that the key(s) being altered be
recalibrated with the 'b' command (page 24) before they take
effect.
Section 2.1, p. 5
Ctrl-A. In Put mode, the command followed by a setting is
programmed into eeprom for the key(s) affected by scope.
1, 4, or 16 keys may be affected. Valid decimal values are:
Values other than the above will be rounded down.
In Get mode, the command will return a single byte according
to the current scope rules (Section 5.2).
This controls key sensitivity by setting the counts of signal
delta needed to cause a detect. Higher = less sensitive.
Numbers should be 6 or greater under most conditions to
reduce the probability of noise detection. Numbers greater
than 20 indicate that the burst length is probably too high.
This setup interacts with Burst Length (^F).
Section 2.2, p. 5
Ctrl-B. In Put mode, the command followed by a setting is
programmed into eeprom for the key(s) affected by scope. 1,
4, or 16 keys may be affected. Valid decimal values are:
Values other than the above will be rounded down.
In Get mode, the command will return a single byte according
to the current scope rules (Section 5.2).
This setup controls the ability of a key to recalibrate quickly
should the signal transition positive quickly, as when a touch
is prolonged enough to cause a recalibration, and when the
key is then 'untouched'. This condition can also be caused by
a foreign object being removed from a key. The value should
normally be set between 6 and 10 counts. If the value is very
lQ
^A
^B
Put
Get
Put
Get
17
17
4
4
0
0
X
X
01 - N
02 - P
20
20
5
5
1, 4, 16
1, 4, 16
Scope
Scope
1
1
25
25
EGATIVE
OSITIVE
6
6
30
30
7
7
Bytes / Cmd
Bytes / Cmd
D
D
ETECT
ETECT
35
35
2
1
2
1
8
8
T
10
45
10
45
T
HRESHOLD
HRESHOLD
Byte 2 Range
Byte 2 Range
0x04..0x40
0x04..0x40
12
55
12
55
n/a
n/a
15
64
15
64
©Quantum Research Group Ltd.
0x04..0x40
0x04..0x40
Returns
Returns
0x01
0x02
21
high, the key will still recover by means of the drift
compensation process, albeit more slowly.
Section 2.3, p. 5
Ctrl-C. In Put mode, the command followed by a setting is
programmed into eeprom for all keys only. The value should
be from 0 to 3, representing hysteresis as follows:
Values other than the above will be rounded down.
The percentage is the distance from the threshold level to the
reference level. The hysteresis level is always closer to the
threshold point than to the reference point. 25% is a
reasonable value under most conditions.
As this parameter is common to all keys, Put and Get
operations send or return only one byte.
Section 2.3, p. 5
Ctrl-D. Identical in operation to ^C above except this applies
to positive 'detections' used to recalibrate the sensor (see ^B
above for details). Uses same hysteresis values as ^C above.
Section 3.5, p. 8
Ctrl-F. In Put mode the command sets the burst length of one
or more keys, according to the current scope. Valid decimal
values are:
Values other than the above will be rounded down.
In Get mode, the command will return a single byte according
to the current scope rules (Section 5.2).
^F sets the length of the acquisition burst on a key by key
basis. This setting is directly proportional to signal gain. This
setup interacts with Negative and Positive Threshold (^A and
^B). Increasing ^F can allow for higher threshold levels and
more robust signals, at the expense of increased radiated
emissions and reduced Cx load capacity.
Special condition: If the value for ^F for a key is set to zero
the burst disabled and the key will not function; the key will
report back with an error code. The timing for the 'phantom
burst' will be preserved so that overall key scan timing will
remain unchanged.
^C
^D
^F
Get
Get
Get
Put
Put
Put
0:
1:
2:
3:
0
12 15 20 25 30 40 50 64
0
0
0
X
X
X
06 - B
03 - N
04 - P
50%
25%
12.5%
0% (no hysteresis)
1
1, 4, 16
Scope
Scope
Scope
2
16
16
16
16
1
URST
OSITIVE
EGATIVE
www.qprox.com QT60161B / R1.03
3
L
Bytes / Cmd
Bytes / Cmd
Bytes / Cmd
ENGTH
4
T
T
HRESHOLD
HRESHOLD
2
1
2
1
2
1
5
7
Byte 2 Range
H
Byte 2 Range
Byte 2 Range
H
0x01..0x03
0x01..0x03
0x00..0x40
10
YSTERESIS
YSTERESIS
n/a
n/a
n/a
0x01..0x03
0x01..0x03
0x00..0x40
Returns
Returns
Returns
0x03
0x04
0x06