BS2 SEROUT freeze when Hyperterminal connects to com port

Amnoid

Apologies if this has been dealt with in the past- but the forum search does not seem to work.

A BS2 connected to a PC is programmed to send a strem of data. The data fills the buffer and can be seen when hyperterminal connetcs to the COM port, but when it is conneted to the COM port, the BS2 stops sending. When Hypertierminal is disconnected, the BS2 resumes sending. The serout comman is basic and simple. Any ideas where to look for the problem.

Thanks

kb2hap

out of curiosity how do you know that it starts back up (sending) after you disconnect? once connected did you do a reset on the stamp to see if it fires back up?· If you have any other info on you connections code ect it would br great.

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DTQ

Jon Williams

Probably because Hyperterminal is reseting (and holding it in reset)·the BASIC Stamp via the ATN line -- which I'm betting is a direct connection on your board (not via caps like on our programming boards). I'm not sure if Hyperterminal lets you set the state of the DTR pin; if it does, change it.

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Amnoid

I found the problem- and unless I missunderstand something very basic, then the documentation is problematic. On the one hand we have the SEROUT help page under the pbasic windows IDE. It shows how to connect to a DB9 serial connector (i.e add a resistor to the SERIN line etc).. Then we have the BS2 schematic pdf which shows something different (i.e. use 0.1uF capacitors on pins 3 and 4 of the BS2 and shows no use of the resistor at all). THIS is what was missing. Once that was done- all worked well. So what is the story?

Jon Williams

There is no issue -- the version that uses the resistor is for standard IO pins, hence they need protection (the resistor provides this). You're using the programming port (which has level shifters on the SOUT an SIN pins), and the connection of the Stamp's ATN line directly to the PC's DTR line can be a problem, especially with Hyperterminal.

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Amnoid

I understand- thanks. But I still think that the documentation should be clearer on this.

kb2hap

If you look in the basic stamp manual (link below) you will see that it is well documented
that there is a difference between program wiring and serin/serout wiring
pages:
30-programing
390-sein
409-serout
(pdf pages not manual pages)


http://www.parallax.com/dl/docs/prod/stamps/BasicStampMan.pdf

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DTQ

Amnoid

Thanks. But I still stand by my criticism of the parallax decumentation- if they have an IDE and it has an online help document- then it too must be able to make this clear. This is not a complicated issue- just one more sentence would have sufficed.

steve_b

don't be too critical!· Just let them know and they are pretty good about taking care of things!

Just look at the rest of their documentation...they're GREAT with support and associated text....you can't find many other companies willing to give access to these resources for free!!

And if you have questions....post them here and there are many minds to help you out!

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·

Steve
http://ca.geocities.com/steve.brady@rogers.com/index.html
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."