AVR-Chat

Daniel Boyer wrote:
>  
>   
>> | By the silence on the list, I assume no-one has ever received data from the
>> | RS-232 interface on a Butterfly?
>> I have done it many times, an I have never had a single problem.  I simply
>> hooked up my butterfly's uart pins to a 9 pin serial connector, opened up
>> Bray's Terminal, set it to show me hex  output, tell it to connect, power up
>> the bfly and then press up on the joystick and you should see a string of
>> characters (they should be '?' if you have your baud set correctly,
>> otherwise adjust your baud rate in the terminal.)  If you can see these
>> characters then you have things setup correctly, if not something is wrong.
>> Once you can see get to this point, you can move on to having your bfly's
>> program send you data.  My butterfly works just fine with at least 7
>> different computers including a Pentium II laptop, an AMD64 laptop, and P4,
>> P3, AMD64, and AMD sempron based desktops... 

   *OR* the RS-232 ports on his particular notebook arte not as tolerane 
of out of specification signalling voltages.  Unfortunately, RS-232D is 
not a "Standard," it is a "Recommended Standard," and many 
manufacturers, particularly of notebook computers, cut cornes on them, 
to save space, weight,
 and/or money.

   Many years ago, I develop data tranmission and normalization 
programming for a vertical market cpmpany that marketed CoGo softeware 
paclkages for Surveyors.  This was back when lassr-based electronics 
theodolites were first becoming popular.  We were writing for the CP/M 
and MS/DOS markets (yeah, this was a LOOOONG time ago).   My programs 
worked fine under CP/M, but we got a lot of calls from people using IBM 
PCs complaining that they couldnot transfer data from their instruments 
to their PCs.

   it tooks us a while to realize that there were two instances of 
essentially that same problem hounding us: 1) IBM had themselves not 
adhered strictly to the RS-232C (D wasn;t out then) standards, and, 
worse yet, many fo the battery operated theodolites were outputting 
uni-polar RS-2332 dsignals (e.g., + and 0 volts, not + and - voltage 
signals, as specified in the standards documents)

.  Our only possible solution was to locate an adapter unit that could 
talk to both the PC and the theodolites.  We were about to design and 
build our own when one of our customers informed us that he had located 
such a device, for only $25 retail...so we bougth 250 of them, and 
offered them as optional addons tot he softwarre package (to be usefd 
when using an IBM PC and any of about 1/2 dozen specific theodolites).  
*yeesh*

tom