Getting LCD to Print Serial


I have a working code which prints speed gathered from a reed switch in the serial monitor.

How do i now get what is being printed in the serial monitor onto my 16, 2 LCD display?

I have wired up and tested my lcd correctly and tested it using the “Hello, World” example on arduino so i know its working.

I am a complete novice and guidance will be appreciated!!

The code which i have, which prints speed from my reed switch is below:

onst int transistorPin = 9; // connected to the base of the transistor

#define reed A0//pin connected to read switch

//storage variables
int reedVal;
long timer;// time between one full rotation (in ms)
float mph;
float radius = 13.5;// tire radius (in inches)
float circumference;

int maxReedCounter = 100;//min time (in ms) of one rotation (for debouncing)
int reedCounter;

void setup(){

reedCounter = maxReedCounter;
circumference = 23.14radius;
pinMode(reed, INPUT);

// TIMER SETUP- the timer interrupt allows precise timed measurements of the reed switch
//for more info about configuration of arduino timers see
cli();//stop interrupts

//set timer1 interrupt at 1kHz
TCCR1A = 0;// set entire TCCR1A register to 0
TCCR1B = 0;// same for TCCR1B
TCNT1 = 0;
// set timer count for 1khz increments
OCR1A = 1999;// = (1/1000) / ((1/(16*10^6))*8) - 1
// turn on CTC mode
TCCR1B |= (1 << WGM12);
// Set CS11 bit for 8 prescaler
TCCR1B |= (1 << CS11);
// enable timer compare interrupt
TIMSK1 |= (1 << OCIE1A);

sei();//allow interrupts


ISR(TIMER1_COMPA_vect) {//Interrupt at freq of 1kHz to measure reed switch
reedVal = digitalRead(reed);//get val of A0
if (reedVal){//if reed switch is closed
if (reedCounter == 0){//min time between pulses has passed
mph = (56.8*float(circumference))/float(timer);//calculate miles per hour
timer = 0;//reset timer
reedCounter = maxReedCounter;//reset reedCounter
if (reedCounter > 0){//don’t let reedCounter go negative
reedCounter -= 1;//decrement reedCounter
else{//if reed switch is open
if (reedCounter > 0){//don’t let reedCounter go negative
reedCounter -= 1;//decrement reedCounter
if (timer > 2000){
mph = 0;//if no new pulses from reed switch- tire is still, set mph to 0
timer += 1;//increment timer

void displayMPH(){

void loop(){
//print mph once a second





I assume that you're using LiquidCrystal library.

Then you can change it to something like this :

lcd.print("Speed: ");

You have to create the lcd object in there somewhere too.

Look Here. Lots of examples at the bottom of the page.