AVR-Chat

Quentin et al,

Do you happen to know if further analysis was done on port usage on 
the Butterfly, specifically the ICP1 (PD0).  A really handy pin to 
have free!

Based on http://members.shaw.ca/climber/avrbutterfly it looks like 
its used by j401 for seg22.

Any ideas?
Adam

--- In AVR-Chat@yahoogroups.com, "Cobb, Quentin" <quentin_cobb@t...> 
wrote:
> This an email that Craig Limber sent to our robotics list, 
commenting on the
> suitability of the Butterfly as a robot controller:
> 
> Hi there;
> 
> I've been doing some analysis of the AVR Butterfly to see what
> usefulness it might be as a robotics controller and thought I would
> share the results with everyone.  Everything I found I got from the
> schematics in the butterfy's userguide I downloaded from Atmel.
> 
> The big thing I was looking for was useful I/O pins, especially
> I/O pins with analog to digital converters or pulse width modulation
> channels.   
> 
> Two 8-bit ports (with associated I/O pins) have connectors that we
> can get at: port B and port D.  Unfortunately, those ports are
> shared with lots of other stuff.
> 
> All four PWM channels are either shared with the navigation switch 
or
> the piezo speaker.  We are stuck with the speaker unless we 
disconnect
> it.  If we want to use the remaining PWM channels we just have to 
make
> sure that no stupid humans fiddles with the button at the same time.
> 
> The rest of port B is shared with the ISP port (which isn't a big
> deal as long as we use those pins for input only), the navigation
> switch or the dataflash.
>  
> Port D also has a connecter but those pins are shared with the LCD.
> According to the schematic they are connected but I am not sure
> if the LCD actually uses them.  I will probably hook soemthing up
> to see if signals are being sent when the LCD gets used.  If they
> are used by the LCD then that entire port will be unuseable unless
> the LCD is turned off.
> 
> However, all is not lost.  There are 4 pins on the JTAG port that
> are useful (PF4-7).  They are also ADC channels.  That's cool.
>  
> The USI interface is also open for us (pe4-6).  The other ports
> such as the USART have some circuitry in between making it less
> likely we can use them for anything else.  
>  
> So, basically, we aren't left with many ports for other stuff.  
> However, it's still a bargain for the cost and what you get.
> 
> I have a little table that shows the pin pin mappings.  
> 
> http://members.shaw.ca/climber/avrbutterfly
> 
> climber
> 
> -----Original Message-----
> From: chrltn101 [mailto:chrltn101@y...] 
> Sent: March 9, 2004 1:18 PM
> To: AVR-Chat@yahoogroups.com
> Subject: [AVR-Chat] Butterfly
> 
> 
> Hi all,
> 
> I was thinking about buying a butterfly, but before doing so I 
wanted to
> ask around and see what kind of reputation the board has (ie. does 
it
> actually do what the data sheets say it supposed to do, what kind of
> hinderances you ran into)
> 
> All comments/recommendations greatly appreciated,
> 
> -John
> 
> 
> 
>  
> Yahoo! Groups Links