Thread: Trying to make the following work but getting invalid type conversion?

This doesn't make sense. What do you expect it to do?

Code:

    ADValues[i] = (float)(*(k + i));

It is of course equivalent to this:

Code:

    ADValues[i] = (float)k[i];

But you can't convert a struct to a float like that.
Do you mean to convert a specific member of the struct to a float?
Or are you trying to reinterpret the underlying bytes of the first part of the struct as a float? (And if so, to what purpose?)

Also, main returns int. Making it void just makes your code non-portable for no good reason.

John.....
My hope is to somehow put each member of the structure into a common array name so that I can then do math on it in a for loop. So to your question....Yes I would like to convert each member of the structure into a float and put it into my array.....Does this make sense??

I am by no means saying this is the best thing to do....I am a hardware guy trying to learn code....The best way I find is to jump in and try things and I learn along the way....So yes I would like to do what I said above

Maybe it is not possible??? but I figure it is bcz all the elements of the struct are the same....Maybe I should make the array an unsigned int and then cast??
Thanks

I still don't really understand what you want to do.
Maybe something like this.
(Note that I removed the pointer part of the typedef since it's generally a bad idea to hide a pointer (unless perhaps it's opaque), and I also got rid of the globals.)

Code:

#include <stdio.h>
#include <inttypes.h>
 
typedef struct {
    uint16_t Vbias;
    uint16_t SiPMCurrent;
    uint16_t LEDCurrent[2];
} t_SenseDataRaw;
 
void voltage(t_SenseDataRaw *k, float *adv) {
    adv[0] = k->Vbias;
    adv[1] = k->SiPMCurrent;
    adv[2] = k->LEDCurrent[0];
    adv[3] = k->LEDCurrent[1];
    for (int i = 0; i < 4; i++)
        adv[i] = adv[i] * 3.3 / 4096;
}
 
int main() {
    t_SenseDataRaw SensorData;
    SensorData.Vbias = 1;
    SensorData.SiPMCurrent = 2;
    SensorData.LEDCurrent[0] = 3;
    SensorData.LEDCurrent[1] = 4;
 
    float ADValues[4];
    voltage(&SensorData, ADValues);
    for (int i = 0; i < 4; i++)
        printf("%f\n", ADValues[i]);
 
    return 0;
}

If the struct members really are the same type (a uint16_t) and represent the same information (a voltage), then you could do this.

Code:

void voltage(t_SenseDataRaw *k, float *adv) {
    uint16_t p = &k->Vbias;  // the first member
    for (int i = 0; i < 4; i++)
        adv[i] = p[i] * 3.3 / 4096;
}