20

0

10

20

30

40

50

60

1

55

109 163 217 271 325 379 433 487 541 595 649 703 757 811 865

Count

0

10

20

30

40

50

60

1.6

1.8

2

2.2

2.4

2.6

2.8

3

3.2

3.4

Delta from Lens Reference Plane to Tracking Surface, Z (mm)

Avg-3sigma

Avg

Avg+3sigma

Data Type:

Upper 8 bits of a 9-bit unsigned integer.

USAGE:

SQUAL (Surface Quality) is a measure of the number of valid features visible by the sensor in the cur-

rent frame. The maximum SQUAL register value is 128. 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 few 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. SQUAL is typically maxi-

mized when the navigation surface is at the optimum distance from the imaging lens (the nominal

Z-height).

Figure 13. Squal values (white paper).

Figure 14. Mean squal vs. Z (white paper).

SQUAL

Address: 0x05

Access: Read

Reset Value: 0x00

Bit

7

6

5

4

3

2

1

0

Field

All rights strictly reserved any portion in this paper shall not be reproduced, copied or transformed to any other forms without permission.

PixArt Imaging Inc.

PixArt Imaging Inc.

ADNS-5050 Optical Mouse Sensor