16*2 LCD display doesn't display my result

Question

I am working on a project to calculate line frequency meter by reciprocal counting with Arduino. I am trying to print the the result on a 16*2 LCD but it is not displaying anything. It just gets on and stuck there. I got the project details from this website Line Frequency Meter Based On Reciprocal Counting

I modified the stock program to interface the LCD but it's not working. Here is the code I am using:

//To read and display the Line frequency 
//using Reciprocal counting method
//clk for 'Time Counter' is generated with 'Tone' function 
//'Time counter' is the physical counter T1
// 'EVENT Counter' is a software counter
#define Fin 6 // input pin for Line freq sig
#define clk 7 // input to ' Time ' counter
#include<LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
boolean FState; // status of the 50 Hz Signal 
int countS; // Signal count
int countC=0; // Clock count
int LineFreq; // Result
void setup() {
 tone(8, 5000); // generates ref freq of 5000 Hz at Pin 8
 pinMode(Fin, INPUT); // set the Fin pin as INPUT
 pinMode(clk, INPUT); // set the clk pin as INPUT
 lcd.begin(16, 2);
}
void loop() { 
 lcd.clear();
 lcd.setCursor(0,0);
 lcd.print("Frequency of signal"); 
 // to avoid partial cycles, first detect the rising edge
 while(digitalRead(Fin)) {
 //wait for '0' state of the Signal
 delayMicroseconds(10);
 }
 //here '0' state
 while(!digitalRead(Fin)) {
 //wait for '1' state
 delayMicroseconds(10);
 }
 //this is the rising edge of the Fin
 //counting can start from here
 // clear the TIME Counter T1
 counterStart1();
 //count 50 of the Line freq signals
 while(countS<50) {
 while(digitalRead(Fin)) {
 //wait for '0' state
 delayMicroseconds(1);
 } 
 //here '0' state
 while(!digitalRead(Fin)) {
 //wait for '1' state
 delayMicroseconds(1);
 }
 // here '1' state
 // here one cycle is just over
 //increment the event counter
 countS=countS+1;
 }
 //here 50 Signal cycles over
 // read the contents of T1 & compute frequency
 countC = getCount1();
 LineFreq = 25000000/countC;
 //send to display
 lcd.setCursor(0,1);
 lcd.print(LineFreq);
 lcd.print(" Hz");
 delay(500); 
 delay(100);
 // clear counter
 countS=0;
 // repeat
}
//The following code is obtained from on-line articles in the public domain
void counterStart1() {
 // hardware counter setup, for the 16-bit Timer1 Timer/Counter
 TCCR1A=0; // reset timer/countern control register A
 TCCR1B=0; // reset timer/countern control register B
 TCNT1=0; // initialize the counter value to 0; this register holds the current count
 // set timer/counter1 hardware as a counter; it counts events on pin Tn (Arduino pin 5)
 TCCR1B = TCCR1B | 7; // Counter Clock source = pin Tn (Arduino pin 5) , start counting now
 // 7 in binary is 0111; OR-ing will set CS10,11,12 to 1's
return;
}
// the following code is obtained from on-line articles in the public domain
// Sub routine to get the current count
unsigned int getCount1() {
 unsigned int count; // this variable returns the current count from the counting register
 TCCR1B = TCCR1B & ~7; // Gate Off / Counter T1 stopped, 
 // this operation clears the bits (CS10,11,12)
 count = TCNT1; // read the counting register
 TCCR1B = TCCR1B | 7; // re-start counting by resetting the bits (CS10,11,12)
 return count; // return the retrieved count to the calling function
}

I am getting a blank screen but the line at very first of the code "Frequency of signal" is printing accurately.

What is wrong with the code and what changes do I need?

Thanks in advance!

• Gerben: Which is it? Not displaying anything, or only displaying "Frequency of signal"?
• Gerben: I fixed your indentation, as it was nearly impossible to read.
• Gerben: If the latter, it seems like you signal on pin 6 isn't there, or is too weak. Ending up with your code waiting for 50 transitions that just aren't there?
• Joy Mukherjee: It is only displaying frequency of the signal only, which is written at the top of code. After that nothing is working. I checked the pin 6 signal And it was working fine.

Answer 1

Your variables are int, which on an Arduino is a 2-byte signed type by default, and has a range of -32768 to 32767.

When you execute:

LineFreq = 25000000/countC;

is the result of the math a 2-byte int, or a 4-byte long? Regardless, you are possibly assigning a 4-byte value to an int.

You can declare LineFreq to be type long, and also append an L to the end of the constant value 25000000 to force long math, so that you have:

long LineFreq;
[...]
LineFreq = 25000000L/countC;