Problem with Switch command

Using Arduino Programming Questions
1

Why does this example not work?

void loop () {
  switch (Program) {
          case 1: 
          BeaconTurnLeftRound(InitNumberofLedsOn, false);
          break; 
          case 2:
          BeaconTurnLeftRound(InitNumberofLedsOn, true);
          break;
  }      
}

and this example does work?

void loop () {
  switch (Program) {
          case 1: 
          int a = 1;
          BeaconTurnLeftRound(InitNumberofLedsOn, false);
          break; 
          case 2:
          BeaconTurnLeftRound(InitNumberofLedsOn, true);
          break;
  }      
}

I don't have a clue.

2

hum... missing context. read How to get the best out of this forum to get example of what's expected for code questions.

in the second example, you can't define a local variable in a case without creating a compound statement around it

void loop () {
  switch (Program) {
          case 1: 
            {
              int a = 1;
              BeaconTurnLeftRound(InitNumberofLedsOn, false);
            }
            break; 
         case 2:
          BeaconTurnLeftRound(InitNumberofLedsOn, true);
          break;
  }      
}

(although the compiler will throw it away since a is not used)

if you are saying code is working if you mess with the stack, it likely means you have a memory overflow somewhere

3

Adding an initialized local variable inside a switch statement will cause all cases beyond that point to not be reachable. The fact that making BeaconTurnLeftRound(InitNumberofLedsOn, true); unreachable makes your sketch 'work' tends to indicate a problem in 'BeaconTurnLeftRound(InitNumberofLedsOn, true);' that causes problems.

4

I don't get your question. The first one is not compiling and the second is compiling. There is only one function.

5

Only ad it so it compiles. What is wrong with the function call?

6

probably error somewhere else... post the compiler output / error message (using code tags)
We are shooting in the dark because you failed to post enough information. Please read the link above.

7 
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h: In function 'BeaconTurnLeftRound':
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
c:\users\f.voogel\documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr\avr\include\util\delay.h:187:28: error: __builtin_avr_delay_cycles expects a compile time integer constant
  __builtin_avr_delay_cycles(__ticks_dc);
                            ^
lto-wrapper.exe: fatal error: C:\Users\f.voogel\Documents\arduino-1.8.16-windows\arduino-1.8.16\hardware\tools\avr/bin/avr-gcc returned 1 exit status
compilation terminated.
c:/users/f.voogel/documents/arduino-1.8.16-windows/arduino-1.8.16/hardware/tools/avr/bin/../lib/gcc/avr/7.3.0/../../../../avr/bin/ld.exe: error: lto-wrapper failed
collect2.exe: error: ld returned 1 exit status
exit status 1
Fout bij het compileren voor board ATtiny
8

Your both right. I called

if (IsBeacon) {DelayTimeToGoRound(63);} else {DelayTimeToGoRound(1);}

with a variable. That was the problem because _delay_ms is expecting an int constant on compiler time. Changed it and now it's acting normal again. Thanks

9

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