ADNS-2030 Avago Technologies US Inc., ADNS-2030 Datasheet - Page 25

• Manufacturer Part Number: ADNS-2030
• Description: Optical Mouse Sensor,DIP
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNS-2030

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SQUAL
Access: Read
Data Type: Eight bit number.
USAGE: SQUAL (Surface QUALity) is a measure of the number of features visible by the sensor in the current frame. The maximum value is 255.
The focus point is important and could affect the SQUAL
value. Figure 37 shows another setup with various Z-
height. This graph clearly shows that the SQUAL count
is dependent on focus distance. The data is obtained by
getting multiple readings over different heights.

256
192
128
64
0
Since small changes in the current frame can result in changes in SQUAL, variations in SQUAL when looking at a surface are expected.
The graph below shows 250 sequentially acquired SQUAL values, while a sensor was moved slowly over white paper. SQUAL is nearly
equal to zero, if there is no surface below the sensor.
0
Field
Bit
25
SQ
7
7
50
SQ
6
6
75
Address: 0x05
Reset Value: 0x00
SQ
5
SQUAL Values (White Paper)
5
100
SQ
125
4
4
Figure 37. Typical SQUAL vs. Height, Z.
(white paper)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
-1.0 -0.8
150
SQ
DELTA FROM NOMINAL FOCUS (mm)
3
3
-0.5
-0.3
175
0
X + 3σ
X
X – 3σ
SQ
2
0.25
2
200
0.5
0.75
SQ
1.0
1
1
225
SQ
250
0
0