AVR-Chat

Stumbling around, I came across the following 
http://www.siwawi.arubi.uni-kl.de/avr_projects/

http://www.siwawi.arubi.uni-kl.de/avr_projects/pbfi.doc has a good 
discussion about port availability.

Adam


--- In AVR-Chat@yahoogroups.com, "Adam Bradley" <adam_j_bradley@y...> 
wrote:
> 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