Hi there. Quite many seem to agree that Your method of doing this is "horrible" or "never seen that done in this way before" ...

Your solution is reading the ADC 16 times every time You want a result out of it. It might slow things down....

I have used a circular buffer to do this:

#define ADC_BUFFER_SIZE 7

static volatile unsigned char __adc_buffer[ADC_BUFFER_SIZE];
static volatile unsigned char __adc_buffer_ptr;

extern void InitAdcReader() {
    for ( __adc_buffer_ptr = 0;
          __adc_buffer_ptr < ADC_BUFFER_SIZE;
          __adc_buffer_ptr++ ) {
        __adc_buffer[__adc_buffer_ptr] = 0;
    }
    __adc_buffer_ptr = 0;
}

extern unsigned char  ReadAdc() {
    unsigned char  ix;
    unsigned short result;

    // Collect one ADC sample
    __adc_buffer[__adc_buffer_ptr] = ADC_DATA_PORT;

    // Advance the pointer
    __adc_buffer_ptr++;
    if (__adc_buffer_ptr >= ADC_BUFFER_SIZE ) {
        __adc_buffer_ptr = 0;
    }

    // Calculate average sum
    result = 0;
    for ( ix = 0; ix < ADC_BUFFER_SIZE; ix++ ) {
        result  += __adc_buffer[ix];
    }

    // Calculate the average
    result = result / (unsigned char)ADC_BUFFER_SIZE;

    return (unsigned char)(result & 0xFF);
}