APPLICATIONS
There are several applications involving the use of a
keyboard device as an input. Listed below are a few
examples.

• Access Control
• Security Systems
• Vending Machine
• Ticketing
  POWER REQUIREMENTS
• Point of Sales
• Kiosks
• General Purpose
  Human-Machine Input
  The module operates at 5 volts and has a typical current
  draw of less than 100 milliamperes. This allows it to be
  conveniently powered from the 5V output pin of the
  Saleng Uno or any Arduino board.
  JUMPER OPTIONS
  When using the I2C interface, the user may switch
  between two I2C slave addresses by installing or
  uninstalling a microjumper between the pin labeled A0
  and the adjacent GND pin.

• I2C address when A0 is not connected to GND=0x36
• I2C address when A0 is connected to GND=0x37
  PIN FUNCTIONS
  The module has a 10-position, double-row, 2.54mm
  pitched header near the power LED indicator. However,
  not all of the pins in this header are relevant to the user.
  Below are descriptions of the pins that are of importance
  to the user.

PRECAUTION

Use level shifters when using 3.3V microcontrollers to
safely connect the Alphanumeric Keyboard module to
your host.

APPLICATION NOTES
Example Using Software Serial
Wiring:

Code:

/* This software is free provided that this notice is 
not removed and proper attribution  is accorded to Layad 
Circuits and its Author(s). Layad Circuits invests 
resources in producing free software. By purchasing 
Layad Circuits' products or utilizing its services, you 
support the continuing development of free software for 
all.   
Author(s): D. Deponio for Layad Circuits Electronics 
Engineering 
Revision: 1.0 - 2019/09/19 - initial creation  
Layad Circuits Electronics Engineering Supplies and 
Services  
B314 Lopez Bldg., Session Rd. cor. Assumption Rd., 
Baguio City, Philippines 
www.layadcircuits.com 
general: info@layadcircuits.com  
sales: sales@layadcircuits.com 
+63-916-442-8565 */ 
#include "SoftwareSerial.h" 
SoftwareSerial LCKeyboard(10, 11); // RX, TX 
enum LCKey{ 
LCKey_u = 0x11, 
LCKey_l,//0x12 
LCKey_d,//0x13 
LCKey_r,//0x14 
LCKey_F1 = 0x82, 
LCKey_F2, //0x83 
LCKey_F3, //0x84 
LCKey_F4, //0x85 
LCKey_F5, //0x86 
LCKey_F6, //0x87 
LCKey_F7, //0x88 
LCKey_F8, //0x89 
LCKey_F9 //0x8A 
}; 

Code: 
/* This software is free provided that this notice is 
not removed and proper attribution is accorded to Layad 
Circuits and its Author(s).Layad Circuits invests 
resources in producing free software. By purchasing 
Layad Circuits'products or utilizing its services, you 
support the continuing development of free softwarefor 
all. 
Author(s): D. Deponio for Layad Circuits Electronics 
Engineering 
Revision: 1.0 - 2019/09/19 - initial creation 
Layad Circuits Electronics Engineering Supplies and 
Services 
B314 Lopez Bldg., Session Rd. cor. Assumption Rd., 
Baguio City, Philippines 
www.layadcircuits.com 
general: info@layadcircuits.com 
sales: sales@layadcircuits.com 
+63-916-442-8565 */ 
#define LCKEYBOARD_I2C_ADDRESS 0x36 //Default 
//Adddress w/ microjumper installed at "A0". 
// #define LCKEYBOARD_I2C_ADDRESS 0x37  
#include <Wire.h> 
enum LCKey{ 
LCKey_u = 0x11, 
LCKey_l,//0x12 
LCKey_d,//0x13 
LCKey_r,//0x14 
LCKey_F1 = 0x82, 
LCKey_F2, //0x83 
LCKey_F3, //0x84 
LCKey_F4, //0x85 
LCKey_F5, //0x86 
LCKey_F6, //0x87 
LCKey_F7, //0x88 
LCKey_F8, //0x89 
LCKey_F9 //0x8A 
}; 

void setup() { 
// put your setup code here, to run once: 
Serial.begin(9600); // serial monitor 
LCKeyboard.begin(9600); // LC Keyboard 
} 
void loop() { 
// put your main code here, to run repeatedly: 
if(LCKeyboard.available()){ 
uint8_t c = LCKeyboard.read(); // read the key 
if(c){ 
// nonprintable characters 
if(c == '\e') Serial.println(F("ESC")); 
else if(c == 0x7F) Serial.println(F("DEL")); 
else if(c == '\b') Serial.println(F("BACK")); 
else if(c == '\t') Serial.println(F("TAB")); 
else if(c == LCKey_u) Serial.println(F("UP")); 
else if(c == LCKey_l) Serial.println(F("LEFT")); 
else if(c == LCKey_d) Serial.println(F("DOWN")); 
else if(c == LCKey_r) 
Serial.println(F("RIGHT")); 
// function keys 
else if(c == LCKey_F1) Serial.println(F("F1")); 
else if(c == LCKey_F2) Serial.println(F("F2")); 
else if(c == LCKey_F3) Serial.println(F("F3")); 
else if(c == LCKey_F4) Serial.println(F("F4")); 
else if(c == LCKey_F5) Serial.println(F("F5")); 
else if(c == LCKey_F6) Serial.println(F("F6")); 
else if(c == LCKey_F7) Serial.println(F("F7")); 
else if(c == LCKey_F8) Serial.println(F("F8")); 
else if(c == LCKey_F9) Serial.println(F("F9")); 
// printable characters 
else Serial.print((char)c); 
} 
} 
} 

void setup() { 
// Wire.setClock(100000); 
// Wire.setClock(400000); 
Wire.begin();        
// join i2c bus 
Serial.begin(9600);  // start serial for output 
} 
void loop() { 
//Request a byte from the Alphanemuric Keyboard. 
Wire.requestFrom(LCKEYBOARD_I2C_ADDRESS, 1); 
if (Wire.available()) {  
uint8_t c = Wire.read(); // read the key 
if(c){ 
// nonprintable characters 
if(c == '\e') Serial.println(F("ESC")); 
else if(c == 0x7F) Serial.println(F("DEL")); 
else if(c == '\b') Serial.println(F("BACK")); 
else if(c == '\t') Serial.println(F("TAB")); 
else if(c == LCKey_u) Serial.println(F("UP")); 
else if(c == LCKey_l) Serial.println(F("LEFT")); 
else if(c == LCKey_d) Serial.println(F("DOWN")); 
else if(c == LCKey_r) 
Serial.println(F("RIGHT")); 
// function keys 
else if(c == LCKey_F1) Serial.println(F("F1")); 
else if(c == LCKey_F2) Serial.println(F("F2")); 
else if(c == LCKey_F3) Serial.println(F("F3")); 
else if(c == LCKey_F4) Serial.println(F("F4")); 
else if(c == LCKey_F5) Serial.println(F("F5")); 
else if(c == LCKey_F6) Serial.println(F("F6")); 
else if(c == LCKey_F7) Serial.println(F("F7")); 
else if(c == LCKey_F8) Serial.println(F("F8")); 
else if(c == LCKey_F9) Serial.println(F("F9")); 
// printable characters 
else Serial.print((char)c); 
} 
} 
}