Channel numbering when using QMatrix acquisition method

Figure 1illustrates a QMatrix capacitive sensing solution which uses 4 X lines and 4 Y lines thereby providing a 16 channel solution.

Note:

  1. 1.

    All channels selected for a specific rotor or slider should be on a single Y line.

  2. 2.

    The choice of ports for X and Y lines is left to the user to based on the availability of the pins available in the particular device selected.

The channel numbering for QMatrix configuration follows a matrix pattern with the channel numbers starting from 0 for the matrix intersection (X0Y0 ) and increasing along the X lines for a given Y line ( Channel 1 is X1Y0 ) and then moving on to the row number 0 for the next column. Figure 1 lists the possible channel numbers and the associated X/Y line associations for the different configurations of QMatrix library variants.

A group of channels form a sensor and the sensor numbering is determined by the order in which the user defines the association of channels and uses them as a sensor.

The channel numbering is fixed for a specific library variant based on the number of X and Y lines used whereas the sensor numbering is determined at the time of usage based on the order in which the user defines the association of the channels to create a sensor.

Figure 1. Channel Numbering for QMatrix acquisition method libraries

Table 1. Channel numbers for QMatrix configurations

Line label

4 channel

(4 x 1)

8 channel

(4 x 2)

16 channel

(8 x 2)

16 channel

(4 x 4)

32 channel

(8 x 4)

56 channel

(8 x 7)

64 channel

(8 x 8)

Channel 0

X0Y0

X0Y0

X0Y0

X0Y0

X0Y0

X0Y0

X0Y0

Channel 1

X1Y0

X1Y0

X1Y0

X1Y0

X1Y0

X1Y0

X1Y0

Channel 2

X2Y0

X2Y0

X2Y0

X2Y0

X2Y0

X2Y0

X2Y0

Channel 3

X3Y0

X3Y0

X3Y0

X3Y0

X3Y0

X3Y0

X3Y0

Channel 4

N/A

X0Y1

X4Y0

X0Y1

X4Y0

X4Y0

X4Y0

Channel 5

N/A

X1Y1

X5Y0

X1Y1

X5Y0

X5Y0

X5Y0

Channel 6

N/A

X2Y1

X6Y0

X2Y1

X6Y0

X6Y0

X6Y0

Channel 7

N/A

X3Y1

X7Y0

X3Y1

X7Y0

X7Y0

X7Y0

Channel 8

N/A

N/A

X0Y1

X0Y2

X0Y1

X0Y1

X0Y1

Channel 9

N/A

N/A

X1Y1

X1Y2

X1Y1

X1Y1

X1Y1

Channel 10

N/A

N/A

X2Y1

X2Y2

X2Y1

X2Y1

X2Y1

Channel 11

N/A

N/A

X3Y1

X3Y2

X3Y1

X3Y1

X3Y1

Channel 12

N/A

N/A

X4Y1

X0Y3

X4Y1

X4Y1

X4Y1

Channel 13

N/A

N/A

X5Y1

X1Y3

X5Y1

X5Y1

X5Y1

Channel 14

N/A

N/A

X6Y1

X2Y3

X6Y1

X6Y1

X6Y1

Channel 15

N/A

N/A

X7Y1

X3Y3

X7Y1

X7Y1

X7Y1

Channel 16

N/A

N/A

N/A

N/A

X0Y2

X0Y2

X0Y2

Channel 17

N/A

N/A

N/A

N/A

X1Y2

X1Y2

X1Y2

Channel 18

N/A

N/A

N/A

N/A

X2Y2

X2Y2

X2Y2

Channel 19

N/A

N/A

N/A

N/A

X3Y2

X3Y2

X3Y2

Channel 20

N/A

N/A

N/A

N/A

X4Y2

X4Y2

X4Y2

Channel 21

N/A

N/A

N/A

N/A

X5Y2

X5Y2

X5Y2

Channel 22

N/A

N/A

N/A

N/A

X6Y2

X6Y2

X6Y2

Channel 23

N/A

N/A

N/A

N/A

X7Y2

X7Y2

X7Y2

Channel 24

N/A

N/A

N/A

N/A

X0Y3

X0Y3

X0Y3

Channel 25

N/A

N/A

N/A

N/A

X1Y3

X1Y3

X1Y3

Channel 26

N/A

N/A

N/A

N/A

X2Y3

X2Y3

X2Y3

Channel 27

N/A

N/A

N/A

N/A

X3Y3

X3Y3

X3Y3

Channel 28

N/A

N/A

N/A

N/A

X4Y3

X4Y3

X4Y3

Channel 29

N/A

N/A

N/A

N/A

X5Y3

X5Y3

X5Y3

Channel 30

N/A

N/A

N/A

N/A

X6Y3

X6Y3

X6Y3

Channel 31

N/A

N/A

N/A

N/A

X7Y3

X7Y3

X7Y3

Channel 32

N/A

N/A

N/A

N/A

N/A

X0Y4

X0Y4

Channel 33

N/A

N/A

N/A

N/A

N/A

X1Y4

X1Y4

Channel 34

N/A

N/A

N/A

N/A

N/A

X2Y4

X2Y4

Channel 35

N/A

N/A

N/A

N/A

N/A

X3Y4

X3Y4

Channel 36

N/A

N/A

N/A

N/A

N/A

X4Y4

X4Y4

Channel 37

N/A

N/A

N/A

N/A

N/A

X5Y4

X5Y4

Channel 38

N/A

N/A

N/A

N/A

N/A

X6Y4

X6Y4

Channel 39

N/A

N/A

N/A

N/A

N/A

X7Y4

X7Y4

Channel 40

N/A

N/A

N/A

N/A

N/A

X0Y5

X0Y5

Channel 41

N/A

N/A

N/A

N/A

N/A

X1Y5

X1Y5

Channel 42

N/A

N/A

N/A

N/A

N/A

X2Y5

X2Y5

Channel 43

N/A

N/A

N/A

N/A

N/A

X3Y5

X3Y5

Channel 44

N/A

N/A

N/A

N/A

N/A

X4Y5

X4Y5

Channel 45

N/A

N/A

N/A

N/A

N/A

X5Y5

X5Y5

Channel 46

N/A

N/A

N/A

N/A

N/A

X6Y5

X6Y5

Channel 47

N/A

N/A

N/A

N/A

N/A

X7Y5

X7Y5

Channel 48

N/A

N/A

N/A

N/A

N/A

X0Y6

X0Y6

Channel 49

N/A

N/A

N/A

N/A

N/A

X1Y6

X1Y6

Channel 50

N/A

N/A

N/A

N/A

N/A

X2Y6

X2Y6

Channel 51

N/A

N/A

N/A

N/A

N/A

X3Y6

X3Y6

Channel 52

N/A

N/A

N/A

N/A

N/A

X4Y6

X4Y6

Channel 53

N/A

N/A

N/A

N/A

N/A

X5Y6

X5Y6

Channel 54

N/A

N/A

N/A

N/A

N/A

X6Y6

X6Y6

Channel 55

N/A

N/A

N/A

N/A

N/A

X7Y6

X7Y6

Channel 56

N/A

N/A

N/A

N/A

N/A

N/A

X0Y7

Channel 57

N/A

N/A

N/A

N/A

N/A

N/A

X1Y7

Channel 58

N/A

N/A

N/A

N/A

N/A

N/A

X2Y7

Channel 59

N/A

N/A

N/A

N/A

N/A

N/A

X3Y7

Channel 60

N/A

N/A

N/A

N/A

N/A

N/A

X4Y7

Channel 61

N/A

N/A

N/A

N/A

N/A

N/A

X5Y7

Channel 62

N/A

N/A

N/A

N/A

N/A

N/A

X6Y7

Channel 63

N/A

N/A

N/A

N/A

N/A

N/A

X7Y7
Parent topic: Sequence of Operations and Using the API