STM32 - Cast from icucnt_t to float

[DeSantis]

Hi,
i'm using ICUDriver on STM32f4 but i have a problem when i try to read the return value from "icuGetWidth(icup)" function.
In particular, i can't cast this value to int or float.

[Giovanni]

It is already an unsigned integer.

Giovanni

[DeSantis]

Hi Giovanni,

Code: Select all

static void icuwidthcb(ICUDriver *icup) {

  palSetPad(GPIOD, GPIOD_LED4);
  last_width =icuGetWidth(icup);
}

icucnt_t last_width;

static void SRF05init(){

  uint16_t distance = 0;

  distance= last_width/58;
}

Distance is always 0 and say me the warning "optimized out".

Thank's for the reply

[Giovanni]

Is the callback actually called? try putting a breakpoint there.

Giovanni

[DeSantis]

Yes it is, infact if i put the mouse on "last_width" in debug mode, i can see the right value

thank you

[fred]

Stupid question, but is the value of last_width you're seeing larger than 57? If it's not then integer divide is just going to return 0;

Secondly, declare the variable with volatile if you don't want the optimizer to touch it:

Code: Select all

volatile icucnt_t last_width;