Keyestudio ARDUINO maker learning kit Manual page 123

5 R/W Select read/write(H/L)
6 E Enable signal
7 D0 Date I/O
8 D1 Date I/O
Interface description:
1. two power sources, one for module power, another one for back light, generally use 5V. In this
project, we use 3.3V for back light.
2. VL is the pin for adjusting contrast ratio; it usually connects a potentiometer(no more than 5KΩ)
in series for its adjustment. In this experiment, we use a 1KΩ resistor. For its connection, it has 2
methods, namely high potential and low potential. Here, we use low potential method; connect the
resistor and then the GND.
3. RS is a very common pin in LCD. It's a selecting pin for command/data. When the pin is in high
level, it's in data mode; when it's in low level, it's in command mode.
4. RW pin is also very common in LCD. It's a selecting pin for read/write. When the
pin is in high level, it's in read operation; when it's in low level, it's in write operation.
5. E pin is also very common in LCD. Usually, when the signal in the bus is stabilized, it sends out
a positive pulse requiring read operation. When this pin is in high level, the bus is not allowed to
have any change.
6. D0-D7 is 8-bit bidirectional parallel bus, used for command and data transmission.
7. BLA is anode for back light; BLK, cathode for back light.
4 basic operations of 1602LCD:
Read status input
Write command input
Read data input
Write data input
Connection & sample program
1602 can directly communicate with Arduino. According to the product manual, it has two
connection methods, namely 8-bit connection and 4-bit connection.
8-bit connection method:
keyestudio
RS=L, R/W=H, E=H
RS=L, R/W=H, D0-D7=command
code, E=high pulse
RS=H, R/W=H, E=H
RS=H, R/W=L, D0-D7=data,
E=high pulse
www.keyestudio.cc
13 D6 Date I/O
14 D7 Date I/O
15 BLA Back light power positive
16 BLK Back light power negative
output
output
output
output
D0-D7=status word
none
D0-D7=data
none
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