Question

I am trying to combine two 8-bit number to an unsigned int but no matter what type casting I use, the result is still signed number. The code is complied using CodeWarrior 10.1 for freescale micro processor MC9S08LH64.

Things I tried that did not work
– shift and add the two 8bits number then type cast them to be unsigned int at every step.
– union/struct to combine the two 8-bit type cast them and the result number to unsigned int.
– use unsigned int pointer (code below)

unsigned int acquire_sensor_voltage_internal_adc()
{ //this is internal ADC
     unsigned int result;
     unsigned int* data_ptr;
     char print_buffer [50];
     int_convert cvt;
    //internal adc collecting counts of input voltage
    //______________________________________________

    //writing to ADCSC1A initiate the conversion sequence
    ADCSC1A= 0x09;
    while(!ADCSC1A_COCOA){}

    cvt.parts.p0 = ADCRHA;
    cvt.parts.p1 = ADCRLA;
    data_ptr = &cvt.int_number;
    result = (unsigned int)*data_ptr;

    sprintf(print_buffer,"here!!!>>>>>>>%d\r\n",result);
    serial_sendString(print_buffer,strlen(print_buffer));
    //_______________________________________________
    return (unsigned int) result;
}

//definition of int_convert from.h file
typedef union{
unsigned int int_number;
struct{
    unsigned char p0;
    unsigned char p1;
}parts;
}int_convert;

Answer 1

You could try:

result = ((unsigned)ADCRHA) << 8 | (unsigned)ADCRHB;

And then use the correct format specifier %u instead of %d.