Variable of type float not showing negative float values

Hello BKola.2241,

I would like to thank you for proposing this issue.

Can you please inform me about the exact type of debug window if it was expression view, live expression or something else...?

Also, can you check if you have chosen somewhere casting in your code or the option <Cast To Type> inside your view as shown the figure bellow.

Finally, to know the right solution of this stuff: I would like to see a screenshot of the different values displayed on your debug window! "You can't see the negative measurements on the debug window", so what do you see exactly: a positive value or some other errors?

Wijeden;

It is from the live expression window.At this moment they should go under 0. But they get stuck somewhere around(above) 0.

Just to clarify, each cell of mag_fi_meas is a combination of two 8-bits words, build up through (raw_data[1]<<8 | raw_data[0]); (raw_data[2]<<8 | raw_data[3]); and (raw_data[4]<<8 | raw_data[5]); where the MSB of raw_data[1], raw_data[3] and raw_data[5] is the sign bit (data are stored in the registers using 2's complement)

@Wijeden RHIMI​ the issue was solved. Thank you for your effort

What's the problem of just reading the int16_t data and converting (assigning) it normally to float?

int16_t raw_data[3];
float mag_fi_meas[3];
 
SensorRead(&raw_data, sizeof(raw_data));
 
for (size_t i = 0; i < 3; ++i) {
	mag_fi_meas[i] = raw_data[i];
}

@Piranha​ the data are stored in 8-bit registers. The full data size is 16 bit. So I read each 8 bit aside, join and type cast it to int16_t. At the end divide it by an integer coeficient.

Many sensors support reading all channels and data bytes with a single sequential read operation, in which case my first example is relevant. If it doesn't, you can still do something like this:

float mag_fi_meas[3];
union {
	uint8_t bytes[2];
	int16_t value;
} raw_data;
 
for (size_t i = 0; i < 3; ++i) {
	raw_data.bytes[0] = SensorRead(i, LSB);
	raw_data.bytes[1] = SensorRead(i, MSB);
	mag_fi_meas[i] = (float)raw_data.value / (float)COEFFICIENT;
}