arduino uno ph monior

hi need some help on merging the code to display the ph to a 16*2 lcd display.

#include <SoftwareSerial.h> //we have to include the SoftwareSerial library, or else we can't use it.
#define rx 2 //define what pin rx is going to be.
#define tx 3 //define what pin Tx is going to be.

SoftwareSerial myserial(rx, tx); //define how the soft serial port is going to work.

char ph_data[20]; //we make a 20 byte character array to hold incoming data from the pH.
char computerdata[20]; //we make a 20 byte character array to hold incoming data from a pc/mac/other.
byte pc_debug=1; //if you would like to debug the pH Circuit through the serial monitor(pc/mac/other). if not set this to 0.
byte received_from_computer=0; //we need to know how many characters have been received.
byte received_from_sensor=0; //we need to know how many characters have been received.
byte arduino_only=0; //if you would like to operate the pH Circuit with the arduino only and not use the serial monitor to send it commands set this to 1. The data will still come out on the serial monitor, so you can see it working.
byte startup=0; //used to make sure the arduino takes over control of the pH Circuit properly.
float ph=0; //used to hold a floating point number that is the pH.
byte string_received=0; //used to identify when we have received a string from the pH circuit.

void setup(){
Serial.begin(38400); //enable the hardware serial port
myserial.begin(38400); //enable the software serial port
}

void serialEvent(){ //this interrupt will trigger when the data coming from the serial monitor(pc/mac/other) is received.
if(pc_debug==1){ //if pc debug is set to 0 this function will be bypassed.
received_from_computer=Serial.readBytesUntil(13,computerdata,20); //we read the data sent from the serial monitor(pc/mac/other) until we see a . We also count how many characters have been received.
computerdata[received_from_computer]=0; //we add a 0 to the spot in the array just after the last character we recived. This will stop us from transmiting incorrect data that may have been left in the buffer.
myserial.print(computerdata); //we transmit the data received from the serial monitor(pc/mac/other) through the soft serial port to the pH Circuit.
myserial.print('\r'); //all data sent to the pH Circuit must end with a .
}
}

void loop(){

if(myserial.available() > 0){ //if we see that the pH Circuit has sent a character.
received_from_sensor=myserial.readBytesUntil(13,ph_data,20); //we read the data sent from ph Circuit untill we see a . We also count how many character have been recived.
ph_data[received_from_sensor]=0; //we add a 0 to the spot in the array just after the last character we recived. This will stop us from transmiting incorrect data that may have been left in the buffer.
string_received=1; //a flag used when the arduino is controlling the pH Circuit to let us know that a complete string has been received.
Serial.println(ph_data); //lets transmit that data received to the serial monitor.
}

if(arduino_only==1){ //if you set arduino_only to = 1.
if (startup==0){ //if the arduino just booted up, we need to set some things up first.
pc_debug=0; //make sure pc_debug is set to 0. You will no longer be able to write commands to the pH circuit in the serial monitor.
myserial.print("e\r"); //take the pH Circuit out of continues mode.
delay(50); //on start up sometimes the first command is missed.
myserial.print("e\r"); //so, let’s send it twice.
delay(50); //a short delay after the ph Circuit was taken out of continues mode is used to make sure we don’t over load it with commands.
startup=1; //startup is completed, let's not do this again during normal operation.
}

delay(800); //we will take a reading ever 800ms. You can make this much longer or shorter if you like.
myserial.print("R\r"); //send it the command to take a single reading.
if(string_received==1){ //did we get data back from the ph Circuit?
ph=atof(ph_data); //many people ask us "how do I convert a sting into a float?" this is how...(pretty tough)
if(ph>=7.5){Serial.println("high\r");} //This is the proof that it has been converted into a string.
if(ph<7.5){Serial.println("low\r");} //This is the proof that it has been converted into a string.
string_received=0;} //reset the string received flag.
}

}
thats the code im using

thats the code im using

Which is improperly posted, and, frankly, looks like crap. At a minimum, you need to use Tools + Auto Format before posting code. And, you need to use code tags (generated by the # icon) when posting code.

Where is the other code you want to merge? What have you tried? What were the results?