[sdiy] dave smith *instruments*

[David Brown]

I actually do just the opposite for my LCD displays.  I build a ram 
buffer for the contents and put whatever data however fast into the 
memory.  On a timer interrupt I update the LCD.  I don't remember the 
rate but it is fairly fast.  The ram can actually be much longer than 
the LCD so scrolling is just setting the starting address of the 
buffer.  I know oftentimes I am writing the same data to the display 
but it works great when the data is changing quickly.

I would also read the encoders on an interrupt as well as you described.

Dave

At 09:57 AM 2/1/2010, Antti Huovilainen wrote:
>On Mon, 1 Feb 2010, Tom Wiltshire wrote:
>
>>So if someone turns the rotary encoder really quickly, you can't 
>>update the LCD before the encoder has moved again. This leaves you 
>>having to choose between letting the LCD update finish before you 
>>check the rotary encoder again (e.g. ignore the encoder) or check 
>>the encoder but don't always bother to update the LCD if it's going 
>>too fast (e.g. ignore the LCD).
>
>The correct way is to use a fastish (~500 Hz) timer interrupt to 
>read the encoders and update the internal counters. Then the actual 
>processing & display code can deal with them at whatever rate is 
>appropriate. This way the worst that can happen is that some values 
>are skipped over.
>
>Antti
>
>"No boom today. Boom tomorrow. There's always a boom tomorrow"
>   -- Lt. Cmdr. Ivanova