ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 41

• Manufacturer Part Number: ra8806
• Description: Two Layers Character/graphic Lcd Controller
• Manufacturer: RAIO Technology Inc.

Preliminary Version 1.2
RAiO
6-4
TECHNOLOGY INC.
Users only need to connect the touch panel signals -- XL, XR, YU, and YD to RA8806. It will
continuously monitor the panel and wait for touch event. When the event is occurred, a divided voltage
on panel caused by touch is sensed and transferred by ADC to determine the location. After the value of
X-axis and Y-axis are transferred and stored in corresponding registers respectively, the touch panel
controller will issue an interrupt to inform MPU to process it.
RA8806 built in a 10-bit ADC and control circuits to connect with 4-wires resistance type touch panel.
Resistive Touch Panel is composed of two layer extremely thin resistive panel, such as Figure 6-16.
There is a small gap between these two-layer panels. When external force press a certain point, the
two-layer resistive panels will be touched, which is short. Because the end points of two-layer have
electrodes (XL, XR, YU, YD), such as Figure 6-17, a comparative location will be detected with some
switches in coordination.
Touch Panel
Figure 6-17 : Control Switch of Touch Panel
VDD
XL
YU
YD
SW0
Figure 6-16：Touch Panel
XL
SW2
SW3
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VDD
YU
YD
Resistor -Y
Resistor -X
GND
Two Layers Character/Graphic LCD Controller
XR
SW1
Y Plate
XR
Electrode
X Plate
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RA8806