This is super long, but bear with me. So I made buzzers for my HiQ team and am finding some very puzzling things. So lets say p1 is blue and p2 is green. The led lights up with the color that wins. The buzzers are hit almost simultaneously. The led shows that green won, the serial monitor shows that p1(blue) buzzed in .203 seconds after it hit zero and p2(green) buzzed in .259 seconds after it hit zero(so according to that blue should've won), and the lcd says that p1(blue) buzzed in 1.35 seconds after it hit zero and p2(green) buzzed in .436 seconds after it hit zero(order is consistent with led, but the buzzers were almost hit at the same time). These results seemingly don’t have a pattern because sometimes the serial monitor makes sense, and sometimes the lcd makes sense, and there doesn't seem to be a numerical pattern. I have no way to check the validity of the led. This is all almost splitting hairs because when pressed noticeably at different times the results are correct (the numerical validity is not known but the lcd and serial monitor always show different values.) I am posting my code wondering if anyone has ANY clue why these results are so different. I believe the print statements are almost identical.
#include <SoftwareSerial.h> //include the needed libraries
#include <LiquidCrystal.h>
// initialize the lcd library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
/*
HiQ buzzer practice program
written By Alex Rodgers
----------------------------------------------------------------------------
I wrote this due to the HiQ team I am part of needing practice buzzers.
***********************************
* *
* LCD D14 pin------D2 *
* LCD D13 pin------D3 *
* LCD D12 pin------D4 *
* LCD D11 pin------D5 *
* P1's button------D6 *
* P2's button------D7 *
* Blue led(rgb)----D9 *
* Green led(rgb)---D10 *
* LCD enable pin---D11 *
* LCD RS pin-------D12 *
* 7 seg RX pin-----D13 *
* *
***********************************
*/
int timeansw=16;//how long to count down from
const int softwareTx = 13; //define what pin to use for tx to 7 seg display
SoftwareSerial s7s(0, softwareTx); //define what pins to use for 7 seg display serial
const int p1=6; //define all needed variables
const int p2=7;
const int led1=9;
const int led2=10;
int p1answ=1;
int p2answ=1;
int reading1;
int previous1=HIGH;
int reading2;
int previous2=HIGH;
long p1time=0;
long p2time=0;
long debounce=200;
int led1read=LOW;
int led2read=LOW;
int p1timex=0;
int p2timex=0;
//button 2
// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0; // will store last time LED was updated
// constants won't change :
const long interval = 1000; // interval at which to blink (milliseconds)
void setup() {
pinMode(p1, INPUT_PULLUP); //buttons configured as inputs but with a pullup
pinMode(p2, INPUT_PULLUP);
pinMode(led1, OUTPUT); //leds configured as outputs
pinMode(led2, OUTPUT);
digitalWrite(led1, LOW); //make sure leds are off
digitalWrite(led2, LOW);
timeansw=(timeansw+1);
s7s.begin(9600); //begin communication with display
Serial.begin(9600); //begin serial communication
lcd.begin(16, 2); //define how many characters are on the lcd
s7s.write(0x76); //clear display
s7s.write(0x7A); //
s7s.write((byte) 40);
s7s.print("-HI-"); //print hi on display
lcd.setCursor(0, 0);
lcd.print("HiQ buzzers"); //print to lcd
lcd.setCursor(0, 1);
lcd.print("Written: Alex R");
Serial.println(""); //now we are printing to serial
Serial.println("HiQ buzzer practice program");
Serial.println("Written by Alex Rodgers March, 2016");
delay(2000); //delay so the message can be read
s7s.write(0x76); //clear 7 seg display
lcd.clear(); //clear lcd
}
void loop() {
reading1=digitalRead(p1); //check pin modes
reading2=digitalRead(p2);
led1read=digitalRead(led1);
led2read=digitalRead(led2);
if (reading1 == LOW && previous1 == HIGH && p1answ == 1){
lcd.setCursor(0,0);
p1answ=2;
if (timeansw==0){
p1timex=(millis()-previousMillis);
if(led2read==LOW){
digitalWrite(led1, HIGH);
}
lcd.print("p1 ");
lcd.print(p1timex/1000);
lcd.print(".");
lcd.print(p1timex%1000);
lcd.println("s late");
Serial.print("p1 is ");
Serial.print(p1timex/1000);
Serial.print(".");
Serial.print(p1timex%1000, 4);
Serial.println(" seconds late");
} else{
p1timex=((millis()-previousMillis)+((timeansw-1))*1000);
lcd.print("p1 ");
lcd.print(p1timex/1000);
lcd.print(".");
lcd.print(p1timex%1000);
lcd.println("s early");
Serial.print("p1 is ");
Serial.print("p1 is ");
Serial.print(p1timex/1000);
Serial.print(".");
Serial.print(p1timex%1000, 4);
Serial.println(" seconds early");
}
}
if (reading2 == LOW && previous2 == HIGH && p2answ == 1){
p2answ=2;
if (timeansw==0){
p2timex=(millis()-previousMillis);
if(led1read==LOW){
digitalWrite(led2, HIGH);
}
lcd.setCursor(0,1);
lcd.print("p2 ");
lcd.print(p2timex/1000);
lcd.print(".");
lcd.print(p2timex%1000);
lcd.print("s late");
Serial.print("p2 is ");
Serial.print(p2timex/1000);
Serial.print(".");
Serial.print(p2timex%1000, 4);
Serial.println(" seconds late");
} else{
p2timex=((millis()-previousMillis)+((timeansw-1))*1000);
lcd.setCursor(0,1);
lcd.print("p2 ");
lcd.print(p2timex/1000);
lcd.print(".");
lcd.print(p2timex%1000);
lcd.print("s early");
Serial.print("p2 is ");
Serial.print(p2timex/1000);
Serial.print(".");
Serial.print(p2timex%1000, 4);
Serial.println(" seconds early");
}
}
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval && timeansw>0) {
if (timeansw>0){
timeansw = timeansw-1;
}
previousMillis = currentMillis;// save the last time you blinked the LED
s7s.write(0x76); //clear display
s7s.write(0x79); //set cursor
s7s.write(0x2); //cursor position
s7s.write(timeansw/10); //write the tens place of time
if (timeansw >= 10){ //check if time left is more than 10
s7s.write(0x79); //set cursor
s7s.write(0x3); //cursor position
s7s.write(timeansw - 10); //write the one's place of time
} else{ //if time left is less than 10
s7s.write(0x79); //set cursor
s7s.write(0x3); //cursor position
s7s.write(timeansw); //set time
}
}
}
(In practice, it would not likely make a perceptible difference.)