global variables and if (irrecv.decode(&results))

Using Arduino Programming Questions
#1

I am using global variables to hold the result of a comparison of an IR keypad button selection.

Within my get_key() function, the variables do not get changed according to the
if (irrecv.decode(&results))
Always true, set to 1, even when no key pressed.

Not sure why, if turning LED on and off WITHIN the function does work according to the same compare test.

[code]
#include <IRremote.h> // use the library for IR

const int receiver = 3; // pin 1 of IR receiver to Arduino digital pin 3
const int sounder =  2;
const int opto = 4;
const int mode = 5;

IRrecv irrecv(receiver); // create instance of 'irrecv'

decode_results results;
int array1[264];
int array2[264];
int key = 0;
int ok = 0;
int up = 0;
int down = 0;
//unsigned long last1 = millis();

void setup()

{  
  pinMode(sounder, OUTPUT);digitalWrite(sounder, LOW);
  pinMode(opto, INPUT_PULLUP);
  pinMode(mode, INPUT_PULLUP);
  irrecv.enableIRIn();
  Serial.begin(9600);
}
void beep()
{
  digitalWrite(sounder,HIGH);delay(100);digitalWrite(sounder,LOW);
}
  
void get_key()
{
  if (irrecv.decode(&results))
  {
   Serial.print (results.value);//debug
   Serial.print ("\n");
   if (results.value == 0xFF4AB5)key = 0;
   if (results.value == 0xFF6897)key = 1;
   if (results.value == 0xFF9867)key = 2;
   if (results.value == 0xFFB04F)key = 3;
   if (results.value == 0xFF02FD){ok = 1;} else {ok = 0;}
   if (results.value == 0xFF629D){up = 1;} else {up = 0;}
   if (results.value == 0xFFA857){down = 1;}else {down = 0;}
   
  irrecv.resume();
  }
}

void loop()
{
  int val = digitalRead(mode);
  while (val = HIGH)
  {
    int val2 = digitalRead(opto);
    while (val2 = LOW)
    {delay(1000);}//temp reverse assume beam interrupted debug
    //stop_motor()
    
    for (int pointer = 0;pointer<264;pointer++)
    {
      ok = 0;up = 0;down = 0;
      get_key();
      array1[pointer] = key;
      delay (300);
      if (ok = 1)//debug test
      {
      Serial.print ("ok = 1");//debug
      Serial.print ("\n");
      }
      if (ok = 1)beep();
      ok = 0;up = 0;down = 0;
      get_key();
      if (up = 1)
      {
      Serial.print ("up = 1");//debug
      Serial.print ("\n");
      array2[pointer] += array2[pointer];}//also echo to UART
      if (down = 1)
      {
      Serial.print ("down = 1");//debug
      Serial.print ("\n");
      array2[pointer] -= array2[pointer];}//also echo to UART
      if (ok = 1){beep();delay(200);beep();}
    }
  }

    Serial.print(array1[1]);//debug
    Serial.print(array2[1]);
    Serial.print("/n");
}

[/code]

irrx.ino (1.24 KB)

#2

      if (ok = 1)//debug testDid you perhaps mean      if (ok == 1)//debug test? :wink:

#3

yes, thanks.
that old 'assignment' = instead of compare ==
fool I am!

but why doesn't the 'while' need the same true/false ==?
while (val = HIGH)

val isn't assigned to HIGH..

#4

simplystupid:
yes, thanks.
that old 'assignment' = instead of compare ==
fool I am!

but why doesn't the 'while' need the same true/false ==?
while (val = HIGH)

val isn't assigned to HIGH..

True. HIGH is assigned to val. Your terminology is backwards. But if you want a possible reason, it could be that line never gets executed. Better just put it aside for a while and then proof read the whole program again. Which of course, I don't have time to do.

#5

The while loop needs the same as the if. The statement "while (val = HIGH)" is translated as assignment the HIGH constant to the val and then the val is tested to nonzero. In this case it is infinity loop.

#6

val isn't assigned to HIGH..

How do you know ?

#7

I just glanced at the rest of your code, and the same error is all over the place.

#8