[Amforth-devel] Butterfly Forth Serial Challenges

[Ian J. <ij...@sa...>]

Hi everyone,

I've done enough reading that I think I can ask this question.

I have been puttering with butterfly-s over the last couple of  
months.  I have a simple project that is essentially a complicated  
thermostat.  I ended up choosing amforth as the platform for a lot of  
reasons interactive, fast, reasonably small etc.  I don't get a lot of  
time to play.

I've been able to load several versions of amforth, most recently 3.4  
but all of them seem to exhibit some kind of serial interface issue.   
I'm looking for suggestions to debug this problem.

I'm using FreeBSD 6.4 AMD64 for the host platform.  I use avrdude with  
an STK500 connected via /dev/cuad0 then ISP to the butterfly which is  
sitting on an Ecros technology AVR butterfly carrier.  http://www.ecrostech.com/

The ISP provides around 5.2V of VCC to the butterfly and with the same  
12V linear supply from a velleman kit the onboard Ecros regulator  
supplies 3.2V vcc.

So far I have just programmed the existing hex files for the butterfly  
application.  I have not rebuilt the source yet.  I'm still working on  
getting avra configured and I cannot run wine on this host platform.

I've tried running both minicom and the amforth-shell.py.  I've used  
the isp and the on board ecros power supply (not both at once).  I use  
the same serial port and cable for programming as for interactive  
communication with the butterfly.

It appears that amforth is running correctly but there are two "bad"  
behaviours.  One is that I usually have to hit reset 2-3 times  
initially to get the standard amforth prompt.  Sometimes I get garbage  
characters after a reset finally I get the amforth prompt.  I can  
define words and add numbers print simple results after the initial  
difficulty.

The second more troublesome issue is I can't seem to upload a  
significant program.  For instance the marker.frt I was only able to  
get running once.  What happens is when I run the upload command from  
the amforth-shell.py tool I get a dozen +'s as expected then I'll get  
a series of "error!!".

I read the source for the python script and I gather that this  
indicates that the expect script is getting back something  
unexpected.  An error code.  Sometimes I just get timeouts and once  
after many timeouts marker.frt loaded apparently.  I'm not sure if it  
truly worked correctly but I could do:

marker -ian
words \ -ian is listed
-ian
words \ -ian is not listed

All this leads me to think that there is something I'm overlooking for  
serial communications.

One other thing.  I have used the serial interface exactly the same  
way to upload assembler programs using the boot loader, obviously  
without amforth.  So I'm guessing the serial hardware on both the  
butterfly, carrier board, and host computer are OK.?  Either that or  
there is some careful error correction on the boot loader serial  
programming.

Suggestions?

Thanks in advance.

Ian