Ideas of why this may happen? printf makes my code work o.O

[Esteban Gutiérrez Correa]

Hello to all

I have the next code, basically what it does is reading a button state and if it is pressed then the manufacturer data of the BLE package is lets say B, on the contrary when the button is not pressed the data is A.

The riddle comes if I comment the printf line, that as you can see doesn't do anything with the variable, then the manufacturer data is never changed even if the button is pressed for a long time. I've tried changing the printf for a delay, does not work, reading the state before and after this line doesn't matter, as long as I'm doing the instruction.

And for power consumption reasons I can't have the uart module working.

Thanks in advance for your help

[endnode]

Well to execute this while loop you need some events happening otherwise first call of power_manage() will typically hangs inside Soft Device in "wait for event/interrupt". If you use UART printf it generates some after each transfer so it makes your "loop" alive;) If you want to detect GPIO interrupt (= button press) then use GPIOTE. It's enough to init it in interrupt mode, you don't need to do anything in handler if you are fine with this code in main loop...

[Esteban Gutiérrez Correa]

The problem with gpiote is that it increase power consumption, and I need it to work as low as possible About the not happening there is actually something happening each time beacuase it is recreating the manufacturing data each time, in the else part of the code.

[Sigurd]

For low power consumption use the GPIOTE in low accraucy mode to detect the button press. You can set the GPIOTE module to low accuracy mode by calling e.g. the GPIOTE_CONFIG_IN_SENSE_TOGGLE() function with the .hi_accuracy flag set to false.

[endnode]

Or rely on other events like timer or radio notification events (if they consume less power then GPIOTE). But it's obvious that if there is no event then there is no way your firmware would notice change of button press state on GPIO;)