Manual of Board ET-TOUCH PAD 4x4 V2
www.etteam.com
-
8
-
1
3
2
4
5
6
7
8
9
0
SHIFT
HELP
ENTER
CLEAR
Figure 3.4 shows example of status at Pins of Connector 8PIN when releasing single Key(Key 7) or both Key (Key F+Key 7).
Figure 3.5 shows diagram of pressing Key as 1 Key and 2 Keys.
Summarize how to read Key Code as Binary BCD8421
: As mentioned about state of pressing and releasing Key above, when
writing program and it presses single Key, user can check status of pressing/releasing Key from Pin T#/R. If P#/R=0, it means that it pressed
Key; or, if P#/R=1, it means that it does not press any Key. Next, it reads Key Code of the pressed Key from Pin BCD8421 and it will be
used.
If pressing Key F together with another Key, user can check status of pressing Key by Pin T#/R and Pin SHIF#. If T#/R = 0 and
SHIF# = 1, it means that it presses single Key; or, if T#/R = 0 and SHIF# = 0, it means that it presses Key F together with another Key. Next,
it reads Key Code of the pressed Key from Pin BCD8421. When releasing another Key that is pressed together with Key F, it can check
status of releasing Key from either Pin T#/R or Pin SHIF# or both pins because when releasing both Keys that are pressed together, the status
of both Keys is also changed to Logic 1.
3.2 How to read Key Code as ASCII
When reading Key Code as ASCII, user can read the value from Connector ‚RS232 or TTL232‛; it is Serial Port Interface and the
Baud Rate is fixed as 9600 bit/s.
When choosing Connector type, it depends on Port 232 of Board that is connected with Touch PAD; it is either TTL or IC Driver
232. If it is TTL (Rx,Tx is connected from MCU directly), it has to connect signal at Connector TTL232 and set Jumper JP-232 to the
position of TTL232; or, if Port232 of Board is connected through IC Driver 232 or it is connect to RS232 of PC, it has to connect signal at
Connector RS232 of Touch PAD and set Jumper JP-232 to the position of RS232. Remember, whatever Connector user choose, user has to
cross Cables from one side to another side correctly; in this case, it connects Pin Tx with Pin Rx of another side and then connects Pin Rx
with Pin Tx of another side.
The Key Code that is sent out to user is ASCII Code; type of the value that is sent out depends on the state of pressing Key as
follows;
0
1
Logic
Time
Press 1Key
SHIF#
Release
T#/R
0
1
Time
1Key
BCD
Code
Time
Key Code
XXXX
0
1
Logic
Time
Press Key F
Release Key
ALL
T#/R
0
1
Time
BCD
Code
Time
0x0F
XXXX
SHIF#
2 Key
Press Key 2
+
Key Code
SH
IF
#
T#
/R
8
4 2
1
BCD
Key7,KeyF+Key7
