Before reading the value print the result of a ftell() function. This will be the offset the code is reading.

Open the file in the hex editor and find what is the values there.

You may use an reverse code to print what the float should actually be, for instance:

    uint8_t array[4] = {0x99, 0x83, 0x04, 0x3f}; // here you put the 4 bytes on the offset being read.
    float* fp = array;
    printf("%f\n", *fp);

This will print 0.517633.

BTW: Are you checking for errors in you file read, open, write operations? Did you remember to call close in the program that created the binary file?

Here it prints: -224187207951651397809339904294912.000000.

But the reversed value 0xF5 0x30 0xDA 0x3F prints 1.704619

Are you sure the order isn't reversed?

Something like this:

    uint8_t array[sizeof(float)]
    read(array, sizeof(float), 1, filepointer);
    
    uint8_t reverseArray[sizeof(float)];
    for (int i = 0; i < sizeof(float); ++i){
        reverseArray[i] = array[sizeof(float)-i-1];
    }


    float* fp = reverseArray;
    printf("%f\n", *fp);

Try:

d.dword_value = ((uint32_t)b[0] << 24) |
		((uint32_t)b[1] << 16) |
		((uint32_t)b[2] << 8) |
		((uint32_t)b[3]);

I'm quite sure the order was messed up