type conversion problem

scanf() converts ASCII to binary. If the producer program is sending you binary integers, you do not need scanf(). Instead, you would just receive the data directly into your destination integer.

You might use a C union, with a byte array overlaying an integer. Or just use pointer arithmetic.

    U16 myInt;
    U8* nextByte;

    len = 0;
    nextByte = &myInt;
    while (len < sizeof(myInt))
        {
        *nextByte++ = WaitForSerialChar();
        ++len;
        }

You're likely to want the ability to abort the routine on a timeout, and other such improvements for a serious application.

C51 stores integers in big-endian format. If the transmitter sends little-endian, you'll have to reverse the order in which you fill the destination.

scanf() converts ASCII to binary. If the producer program is sending you binary integers, you do not need scanf(). Instead, you would just receive the data directly into your destination integer.

You might use a C union, with a byte array overlaying an integer. Or just use pointer arithmetic.

    U16 myInt;
    U8* nextByte;

    len = 0;
    nextByte = &myInt;
    while (len < sizeof(myInt))
        {
        *nextByte++ = WaitForSerialChar();
        ++len;
        }

You're likely to want the ability to abort the routine on a timeout, and other such improvements for a serious application.

C51 stores integers in big-endian format. If the transmitter sends little-endian, you'll have to reverse the order in which you fill the destination.