how to have anologue input and while loop?

I have a program with a joystick and a LCD. The joystick controls "!"s on the LCD(makes them appear in different places. The joystick if made from potentiometers and when the value gets to a certain point a "!" is suppose to appear on a part of the screen using a while loop. When the value reaches the point to show a "!" on the screen the while loop starts and stops the anologue input from the potentiometers. This makes the value constant forever and the "!" never goes away. An IF statement hasn't worked because i need to clear the screen if the value is not correct for that "!" and that makes it impossible for other "!"s never appear. Are there any solutions to this or other ways of going about it? I am inexperienced so I am in much need of help. (BTW the code is made for four different potentiometers (Two joysticks) but I an only using one joystick (so two potentiometers, sensePinOrange with val1, and, sensePinYellow with val).) CODE:

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

int sensePinYellow =0;

int sensePinOrange =1;

int sensePinBrown =2;

int sensePinBlue =3;

int val = 0;

int val1 = 0;

int val2 = 0;

int val3 = 0;

void setup() {

analogReference(DEFAULT);

Serial.begin(9600);

lcd.begin(16, 2);

}

void loop() {

val = analogRead(sensePinYellow);

val1 = analogRead(sensePinOrange);

val2 = analogRead(sensePinBrown);

val3 = analogRead(sensePinBlue);

Serial. print(" Yellow=");

Serial. print(val); /*930=right 210=left */

Serial. print(" Orange=");

Serial. print(val1); //925=maxup 195=mindown

Serial. print(" Brown=");

Serial. print(val2); //930=right 180=left

Serial. print(" Blue=");

Serial. println(val3); //920=maxup 150=mindown

delay(50);

while (val > 700) {

lcd.setCursor(15,1); //right

lcd.print("!");

}

while (val < 400) {

lcd.setCursor(0,1); //left

lcd.print("!");

}

while (val1 > 700) {

lcd.setCursor(9,0); //up

lcd.print("!");

}

while (val < 400) {

lcd.setCursor(9,1); //down

lcd.print("!");

}

0 michaelwylie over 11 years ago

I would think about it as looking for a change.
if(cursor changed)
{
clear all cursors
write proper cursors
}
The harder part is determining if there was a change. So, think about keeping track of the previous values and comparing them to the newest read ones. If they are different (within tolerance) there was a change. Try thinking about this, and if you can't figure it out, come back an update this post.
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0 Robert Peter Oakes over 11 years ago

Your while loops have no exit criteria, as soon as you read a value within the capture range of one of the while loops it will never exit, exactly as you describe

ie. you read all the values into variables
then based on a variable you perform the while loop, as long as the variable, say Val >700 it will stay in the loop until val is not >700, as you never update val inside the loop, it will never continue out of the loop

what would be better is something like this

void loop() {
    val = analogRead(sensePinYellow);
    val1 = analogRead(sensePinOrange);
    Serial. print(" Yellow=");
    Serial. print(val);      /*930=right 210=left */
    Serial. print(" Orange=");
    Serial. print(val1);      //925=maxup 195=mindown
    delay(50);
if (val > 700) {
      lcd.setCursor(15,1); //right
      lcd.print("!");
    }
    else if(val < 400) {
      lcd.setCursor(0,1); //left
      lcd.print("!");
    }
    if(val1 > 700) {
      lcd.setCursor(9,0); //up
      lcd.print("!");
    }
    else if(val1 < 400) { // I modified this to be Val 1 as it seemed to be what you where trying to do based on the rest of the code
      lcd.setCursor(9,1); //down
      lcd.print("!");
    }

of course there is nothing to clear the screen indicators when it goes out of the range but you can figure that out im sure, and use what Michael describes as a clue

Have fun

Peter
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