Co je spatne?

[Jan Matejka]

A neni to tak, ze se nikdy nestane ze by 256 cyklu cteni AD davalo
stejny vysledek, krome nejakeho patologickeho stavu (preteceni) 0x3FF,
ktery jako jediny zobrazite? Ze by Vam to fungovalo spravne tak jste to
napsal? Zkuste zmensit vyzadovany pocet mereni, treba na 1 nebo 2.

Jan Matejka

> -----Original Message-----
> From: hw-list-bounces@mailman.nethouse.cz 
> [mailto:hw-list-bounces@mailman.nethouse.cz] On Behalf Of Bolek
> Sent: Friday, October 01, 2004 6:38 PM
> To: [HWnews]
> Subject: Re: Co je spatne?
> 
> 
> Je to cast funkce, ktera cela vypada ted takhle:
> 
> uint8_t ReadColumn( uint8_t column)
> // Reads one column, return index of the key pressed
> // Returns 0xFF if the reading is not stable or no key is pressed {
>    // How many reading must be the same before
>    // the value is accepted. It is used to get rid
>    // of transitional effect when the key is pressed
>    uint16_t i, value, prevval;
> 
>    ADMUX = column+4;
> 
>    // Get first reading
>    ADCSRA = admask | adsc;
>    while (ADCSRA & adsc) ;
>    ADCSRA = ADCSRA | adif;
> 
>    prevval = ADCW >> 2;
>    // Loop
>    for (i=1; i<256; i++) {
>        // Start conversion, loop until it is done
>        ADCSRA = admask | adsc;
>        while (ADCSRA & adsc) ;
>        ADCSRA = ADCSRA | adif;
>        // Read value
>        value = ADCW >> 2;
> 
>        if (prevval!=value) return 0xFF;
>        prevval = value;
>    }
> 
>    char buffer[10];
>    sprintf( buffer, "%x%x", ADMUX, value);
>    DisplayText( buffer);
> 
>    if (value>0xE0) return 0xFF;  // No key is pressed, pin is 
> pulled up 
> to AUCC
>    else if (value>0xA0) return 0;
>    else if (value>0x60) return 1;
>    else if (value>0x20) return 2;
>    else return 3;
> }
> 
> Ivo Neubauer wrote:
> 
> > to je jak cast nejake funkce, nebo naky vykousnuti z main ?????
> > 
> > 
> > 
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> -- 
> ====================================================
> Ing. Boleslav Vrany
> 
> Consulting and development in software, electronics,
> modern optics and mechanical engineering.
> 
> e-mail: see my web page or use the form there http://www.bolekvrany.cz
> ICQ: 287 834 668
> tel: (+420) 732 673 905
> 
> 
>