BS2sx two wire serial link....?

Archiver

hello again,

My second attempt at this question:

How can I download from the Stamp editor program to a BS2sx using
only two wires, ground and serial in. Right now when I try to
download, it has 'loopback', but no 'echo', and says no stamps found.
How can I get around this problem ??

Thanks alot....John

Archiver

You can't do it with just two wires. First, the BASIC Stamp must be
remotely reset by blipping the ATN (DTR on serial port) line. Then, the
editor expects an echo to confirm that the transmitted by made it to the
module.

-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office

---

Original Message

---

From: jking77777 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=RbYPHbLhrtA__U61W5KMJWocBvYeAclfjP_JSJDuVjnoZ6WcdQLCd7lrMbskQvvSm9mDDx1GPEOzk_XD]jking@n...[/url
Sent: Wednesday, May 05, 2004 10:52 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] BS2sx two wire serial link....?



hello again,

My second attempt at this question:

How can I download from the Stamp editor program to a BS2sx using
only two wires, ground and serial in. Right now when I try to
download, it has 'loopback', but no 'echo', and says no stamps found.
How can I get around this problem ??

Thanks alot....John

Archiver

First a question: Why, what are you trying to do?
Isn't the Parallax supplied approach sufficient
for you? What is the benefit of two wires over
6 wires? (TX, RX, GND, DTR, RTS-CTS)
(Oh, and you COULD loop-back RTS to CTS at the
PC, so you'd only need 4 wires).

Second -- it COULD be done, but you'd need a
'protocol converter' PIC at both ends of the
connection, and it may not be as reliable as
the Parallax approach. It would also be a lot
of work.

You'd need a PIC at the PC end to 'pretend' to
be a BS2 to keep the IDE happy. Then you'd need
a PIC at the BS2 end to break out the single
recieve line into the reset and serial in lines
needed. Seems a lot more trouble than it's worth
to remove 2 wires.


--- In basicstamps@yahoogroups.com, "jking77777" <jking@n...> wrote:
>
> hello again,
>
> My second attempt at this question:
>
> How can I download from the Stamp editor program to a BS2sx using
> only two wires, ground and serial in. Right now when I try to
> download, it has 'loopback', but no 'echo', and says no stamps
found.
> How can I get around this problem ??
>
> Thanks alot....John

Archiver

> How can I download from the Stamp editor program to a BS2sx using
> only two wires, ground and serial in. Right now when I try to
> download, it has 'loopback', but no 'echo', and says no stamps found.
> How can I get around this problem ??

You can't. The protocol requires that the stamp be reset (this is usually
done by toggling the serial connections ATN line) and that the stamp reply
(via receive data pin). That's two more wires.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)