Arduino: if-compare parameters

arduino, c, c++, embedded

Solution

Add `else` as follows:

    if(mode == MODE_PRESSURE)  
       mode = MODE_ALT; 
    else if(mode == MODE_ALT) # although not need but keep if here also
       mode = MODE_PRESSURE;

You could also use nested-switch:

switch(mode){
     case MODE_PRESSURE: mode = MODE_ALT; 
             break; 

     case MODE_ALT: mode = MODE_PRESSURE; 
             break;
}

Problem

I'm trying to get a small BMP085 barometer project up and running. I want to be able to switch between different modes of operation (MODE_PRESSURE and MODE_ALT). I have `MODE_PRESSURE` and `MODE_ALT` defined as `const int`. ``` const int MODE_PRESSURE = 1; // display pressure and temp const int MODE_ALT = 2; // display altitude relative to sea level int mode; // stores the current mode void setup { mode = MODE_PRESSURE; } void loop { // Read mode button and set mode accordingly int buttonPressed = readButtons(); switch(buttonPressed) { case BTN_MODE: if(mode == MODE_PRESSURE) { mode = MODE_ALT; } if(mode == MODE_ALT) { mode = MODE_PRESSURE; } Serial.println(mode); // <<-- always prints 1 ?! break; } } ``` When the mode button is pressed, I want to toggle the current mode. But I'm stuck at `if(mode == MODE_PRESSURE)`. This statement somehow never evaluates to true...? I'm not very fluent in C, is there something I am missing? Can I not compare `const int` and `int` variables? P.S.: I've also tried `#define` for MODE_PRESSURE and MODE_ALT, and `const byte`, but nothing seems to work.

Original source