Atmel AVR, too slow encoder tics counting

In article <c7fg8j$a1c$1@nemesis.news.tpi.pl>, Umpa 
<?@umpaumpalala.com.invalid> writes
>> How fast are you running the clock on your CPU?
>> What is your clock src?
>>
>I have ATmega16 -- 16 MHz.
>Clock source is internal I think, I didn`t connect any quartz.
>
>Did I do something wrong?
>
An ATMega16 on internal oscillator runs by default at 1MHz not 16MHz. So 
that will make quite a difference.

16Mhz is the max frequency it will go at when using a crystal.
-- 
Tim Mitchell

> What to do to improve frequency ?

Re-write the interrupt code in assembler.  Make sure that your LCD output
function does not disable interrupts.

How fast do you want to go?

> long int licz = 0;

That needs a "volatile".

Umpa schrieb:
>> How fast are you running the clock on your CPU?
>> What is your clock src?
>> 
> I have ATmega16 -- 16 MHz.
> Clock source is internal I think, I didn`t connect any quartz.
> 
> Did I do something wrong?
> 
Have you checked the correct setup for the internal oscillator?
The ATmegas are shipped with internal RC @ 1MHz...

Alexander

> 16Mhz is the max frequency it will go at when using a crystal.
> --
Hurrayy !!!
Maybe it is a cause !!
Tell me please, what cristal shall I attach, where, and what
to set up in my program ?
Or provide me with any document.

Umpa.

> How fast do you want to go?

10 kHz would be enough.
But, above two people have said that
my ATmega16 works with 1MHz
frequency, and I need to attach
cristal. I think, it solves my problem.

Umpa.

In article <c7fobq$os$1@atlantis.news.tpi.pl>, Umpa 
<?@umpaumpalala.com.invalid> writes
>
>> 16Mhz is the max frequency it will go at when using a crystal.
>> --
>Hurrayy !!!
>Maybe it is a cause !!
>Tell me please, what cristal shall I attach, where, and what
>to set up in my program ?
>Or provide me with any document.
>
If you don't have the Mega16 data sheet you can download it from 
www.atmel.com, it contains all the information you need to either attach 
a crystal or change the internal RC oscillator speed.
-- 
Tim Mitchell

One more thing.
I need to use UART transmision.
I bought 11,059 MHz cristal.
If I attach this cristal, will processor
run with 11,059 MHz frequency ?

Umpa.

Umpa schrieb:
>> How fast do you want to go?
> 
> 10 kHz would be enough.
> But, above two people have said that
> my ATmega16 works with 1MHz
> frequency, and I need to attach
> cristal. I think, it solves my problem.

You can set up your internal RC to 8 or 16MHz by progamming the corrseponding fuses. Look at the datasheet!

Alexander

> The second thing is, when I change type of "licz" to
> int (not long int), it can count ticks faster.

Well, you also have to protect the reading of "licz" by a pair
of CLI/SEI (in the main code).  Don't protect the whole LCD call,
but rather copy it to a local autovar in protected fashion, and
then use the copy in the printf/LCD calls.