Keyestudio KS0077, Manual, Page: 84 / 142

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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 the 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.
Four Basic Operations for 1602LCD:
Read status input RS=L, R/W=H, E=H output D0-D7=status word
Write command input RS=L, R/W=H, D0-D7=command
code, E=high pulse
output none
Read data input RS=H, R/W=H, E=H output D0-D7=data
Write data input RS=H, R/W=L, D0-D7=data,
E=high pulse
output none
Hardware Required
1 * Arduino Board
1 * 1602 LCD
1 * Potentiometer
1 * Breadboard
1 * USB Cable
Several* Jumper Wires
Connection & Sample Code
1602 can directly communicate with Arduino. According to the product manual, it has two
connection methods, namely 8-bit connection and 4-bit connection.