BU21049GUL Datasheet, PDF (16/26 Pages) Rohm – 4-wire Resistive Touch Screen Controller

BU21049GUL
Datasheet
●dual coordinates conversion
The touch position of dual touch is convertible for coordinates because the host processor processes the data which the
BU21049GUL outputs. The data outputted changes with the commands received from the host processor as shown in
Table1. The host processor should take data from the BU21049GUL by the burst read via I2C. When reception is stopped
and it resumes before taking all the data, it is again outputted from Byte0.
When using it only by single point detection, it may be end reception to the timing which take each coordinates.
Table1. The output data list of each command
Byte
Command method
X data taking
Command method
Y data taking
0
X
1
coordinate
2
X 2 points
3
paramter
4
5
Dummy
6
-
7
-
8
-
9
-
10
-
11
-
12
-
13
-
14
-
15
-
Y
coordinate
Y 2 points
paramter
Ghost
parameter
-
-
-
-
-
-
-
-
-
-
Command method
Z data taking
Z1
coordinate
Z2
coordinate
Dummy
-
-
-
-
-
-
-
-
-
-
Auto method
X coordinate
Y coordinate
Z1 coordinate
Z2 coordinate
X 2 points
paramter
Y 2 points
paramter
Ghost
parameter
Dummy
Table2. The output data format list
DATA
ByteH
ByteL
Bit07 Bit06 Bit05 Bit04 Bit03 Bit02 Bit01 Bit00 Bit07 Bit06 Bit05 Bit04 Bit03 Bit02 Bit01 Bit00
X coordinate X[11] X[10] X[9] X[8] X[7] X[6] X[5] X[4] X[3] X[2] X[1] X[0] 0
0
0
0
Y coordinate Y[11] Y[10] Y[9] Y[8] Y[7] Y[6] Y[5] Y[4] Y[3] Y[2] Y[1] Y[0] 0
0
0
0
Z1 coordinate Z1[11] Z1[10] Z1[9] Z1[8] Z1[7] Z1[6] Z1[5] Z1[4] Z1[3] Z1[2] Z1[1] Z1[0] 0
0
0
0
Z2 coordinate Z2[11] Z2[10] Z2[9] Z2[8] Z2[7] Z2[6] Z2[5] Z2[4] Z2[3] Z2[2] Z2[1] Z2[0] 0
0
0
0
X 2 points
parameter
PX[9] PX[8] PX[7] PX[6] PX[5] PX[4] PX[3] PX[2] PX[1] PX[0]
0
0
0
0
0 SPX
Y 2 points
parameter
PY[9] PY[8] PY[7] PY[6] PY[5] PY[4] PY[3] PY[2] PY[1] PY[0]
0
0
0
0
0 SPY
Ghost
parameter
GH[11] GH[10] GH[9] GH[8] GH[7] GH[6] GH[5] GH[4] GH[3] GH[2] GH[1] GH[0]
0
0
0 SGH
(*1)The ByteH is the even number Byte. The ByteL is the odd number Byte. It means that X coordinates are ByteH=Byte0 and ByteL=Byte1 when it is taken
with a command method.
X coordinate: Touched coordinate of X. It becomes gravity center coordinate of 2 points at dual touch.
X = ByteH * 16 + ByteL / 16
Y coordinate: Touched coordinate of Y. It becomes gravity center coordinate of 2 points at dual touch.
Y = ByteH * 16 + ByteL / 16
Z1 coordinate: Touched coordinate of Z1. It’s used when calculate touch pressure.
Z1 = ByteH * 16 + ByteL / 16
Z2 coordinate: Touched coordinate of Z2. It’s used when calculate touch pressure.
Z2 = ByteH * 16 + ByteL / 16
The X dual parameter: It is the pointer of table which used when calculate 2 points distance of X-axis.
PX = ByteH * 4 + ByteL / 64 (In the case of SPX=0)
PX = 0x400 – (ByteH * 4 + ByteL / 64) (In the case of SPX=1)
The Y dual parameter: It is the pointer of table which used when calculate 2 points distance of Y-axis.
PY = ByteH * 4 + ByteL / 64 (In the case of SPY=0)
PY = 0x400 – (ByteH * 4 + ByteL / 64) (In the case of SPY=1)
Ghost parameter: It is a value for judging a touch position (the direction of inclination) at dual touch.
GH = ByteH * 16 + ByteL / 16 (In the case of SPY=0)
GH = 0x1000 – (ByteH * 16 + ByteL / 16) (In the case of SPY=1)
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TSZ02201-0Y1Y0F300010-1-2
31.JAN.2012 Rev.001