BU21049GUL Datasheet, PDF (17/26 Pages) Rohm – 4-wire Resistive Touch Screen Controller

BU21049GUL
Datasheet
Table3. Dual coordinates conversion flow
step
1
operation
All the data is acquired and conveted according to procedure (p.16).
2
If required, a filter etc. will be processig to data.
3
If only 1-point touch detection, conversion is end.
4
2 points touch detection:
2 points touch is detected comparing PX、PY and GH with threshold.
If 2-point touch is not detected, conversion is end.
5
X-axis 2-point distance calculation 1:
Data is acquired from the distance conversion table using the maximum of 2 points
distance determined beforehand.
The data is set to PRMX1.
6
X-axis 2-point distance calculation 2:
Data is acquired from the distance conversion table using PX.
The data is set to PRMX2.
7
X-axis 2-point distance calculation 3:
The 2 points distance of X-axis (DX) calculated.
DX = 2048 * (PRMX2 / PRMX1)
8
Y-axis 2-point distance calculation 1:
Data is acquired from the distance conversion table using the maximum of 2 points
distance determined beforehand.
The data is set to PRMY1.
9
Y-axis 2-point distance calculation 2:
Data is acquired from the distance conversion table using PY.
The data is set to PRMY2.
10
Y-axis 2-point distance calculation 3:
The 2 points distance of Y-axis (DY) calculated.
DY = 2048 * (PRMY2 / PRMY1)
11
X-axis 2-point touch coordinate conversion:
X-axis 2-point touch coordinate convert from center position(X) and distance(DX).
X1 = X + DX
X2 = X - DX
12
Y-axis 2-point touch coordinate conversion:
Y-axis 2-point touch coordinate convert from center position(Y), distance(DY) and
ghost value(GH).
When GH more than threshold.
Y1 = Y + DY
Y2 = Y - DY
When GH less than threshold.
Y1 = Y - DY
Y2 = Y + DY
13
It is generated, and since they are not exact coordinates, if 2-point coordinates are
required, they process offset etc.
14
conversion is end.
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TSZ22111・15・001
17/23
TSZ02201-0Y1Y0F300010-1-2
31.JAN.2012 Rev.001