Problems with making a reflex test

Using Arduino Programming Questions
1

We are trying to make a reflex test with an arduino. We got 3 lights which will turn on randomly. When one will turn on, you have to press a button and your reflex time will be printed to a LCD.
Our code is currently not working, there seems to be a problem with the code but we can't find where exactly. We are using the I2C libary by Frank de Brabander for the LCD.

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
long randNumber;
long randdelay;
unsigned long starttijd = millis();
int knop1=2;
int knop2=3;
int knop3=4;
int lamp1=11;
int lamp2=12;
int lamp3=13;
int  knopStatus1 = digitalRead(knop1);
int  knopStatus2 = digitalRead(knop2);
int  knopStatus3 = digitalRead(knop3);


void setup() {  
  randomSeed(analogRead(0));
  pinMode(2, INPUT); //de inputs van het knopjes
  pinMode(3, INPUT);
  pinMode(4, INPUT);
  pinMode(11, OUTPUT); //lampjes
  pinMode(12, OUTPUT);  
  pinMode(13, OUTPUT);
   
  }
void loop(){
  randNumber = random(lamp1,lamp3);

  delay(random(2000,4000));
  digitalWrite(randNumber, HIGH);
while ((knopStatus1) && (lamp1) == HIGH || (knopStatus2) && (lamp2) == HIGH || (knopStatus3) && (lamp3) == HIGH);
{
  unsigned long eindtijd = millis();
  digitalWrite(lamp1, LOW);
  digitalWrite(lamp2, LOW);
  digitalWrite(lamp3, LOW);
  unsigned long ElapsedTime = eindtijd - starttijd;
  lcd.init();
    lcd.clear();          
    lcd.backlight();      
    lcd.setCursor(2,0);    
    lcd.print("time is:");
    lcd.setCursor(2,1);    
    lcd.print(ElapsedTime);
    starttijd = millis(); }
while (knopStatus1 == LOW || knopStatus2 == LOW || knopStatus3 == LOW);{ }
}
2

Increase the chance of getting help by saying what's not happening that should be, and /or what's happening that shouldn't be...

3

For a start, read here and see that random's upper limit is exclusive, so 1 less than the value given...

Parameters

min: lower bound of the random value, inclusive (optional).
max: upper bound of the random value, exclusive.

Returns

A random number between min and max-1. Data type: long.

4

How can we help if you dont say what parts you are using? Provide a link for the LCD please, and explain what is "not working" ie the "lamps" or the LCD display.

5

Shouldn't this be in loop()?

6

We are using a 16x2 LCD. We got the code from: https://lastminuteengineers.com/i2c-lcd-arduino-tutorial/
We tried checking if the arduino loops fully trough the program by using the serial monitor. It does go trough the loop but no light comes on. I suspect its a fault in the code but it might also be a fault in the wiring as im not that experienced. The LCD is not working either but that might be a result of a faulty code.
Also I dont think the variables for knopstatus should be in a loop because those variables only have to be created once but i will give it a try next time i get the chance to work on it

7

Does that also apply when the random function includes variables because if i would use
'''' randNumber = random(lamp0,lamp4);
I dont think it would work because the variables lamp0 and lamp 4 are never mentioned

8

Think again.

Think what their values might be.

9

You have some semicolons in places that while syntactically correct make the program function differently to what (I think) you intend.

while (condition) { do stuff}

is the pattern you want.

while (condition); { do stuff}

is seen by the compiler and sharp eyes IRL as

while (condition);


{do stuff}

if the condition is true, it hangs forever at the while statement.

If the condition is false, the {do stuff} block is executed once.

HTH

a7

10

oh yes now i get it. Thanks, I will try next time I get the chance to work on it

11

Thanks alot, I think this is what was going wrong because in earlier versions of the code, everything worked except for the functions. I will update you when I can work on it.

12

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