Problems with OEMBS2

Archiver

I purchased the OEM BS2 in kit form and assembled it according to the
instructions. If I try to identify the stamp, It says that no basic stamp
was found 90% of the time. When I tried to download something to it, again
it said no basic stamp was found 90% of the time, and when it DID find it,
the download is interrupted. All I have connected is a 9VDC power supply
to the Vin and Vss pins and a serial cable. I tested the ~Reset pin on the
PIC, and it is high. I also checked the voltage between the PIC's Vcc and
GND pins and it's 5V as it should be. I have yet to probe all the lines
with a scope, but I may. Does anyone have some insight as to why this is
happening?

Thanks

Archiver

I'm not sure if this will help or not. When you connect the BS2 you
should have caps for your serial cable. One goes from pin 4 on the
serial cable in series to pin 3 on the stamp and the other goes
between pin 3 and 4 on the stamp. I would also check your ground for
the serial cable.....not sure, you may be getting noise on the line
that's why you may be able to load it sometimes and not others. The
link below shows how the hookup should be.

http://www.parallaxinc.com/downloads/Documentation/Basic%20Stamps/BS2%
20rev%20F%20Schematic.pdf


Chris






--- In basicstamps@y..., Pepsi <pepsi@c...> wrote:
> I purchased the OEM BS2 in kit form and assembled it according to
the
> instructions. If I try to identify the stamp, It says that no
basic stamp
> was found 90% of the time. When I tried to download something to
it, again
> it said no basic stamp was found 90% of the time, and when it DID
find it,
> the download is interrupted. All I have connected is a 9VDC power
supply
> to the Vin and Vss pins and a serial cable. I tested the ~Reset
pin on the
> PIC, and it is high. I also checked the voltage between the PIC's
Vcc and
> GND pins and it's 5V as it should be. I have yet to probe all the
lines
> with a scope, but I may. Does anyone have some insight as to why
this is
> happening?
>
> Thanks

Archiver

The OEM version of the BS2 has those caps on the board already

>I'm not sure if this will help or not. When you connect the BS2 you
>should have caps for your serial cable. One goes from pin 4 on the
>serial cable in series to pin 3 on the stamp and the other goes
>between pin 3 and 4 on the stamp. I would also check your ground for
>the serial cable.....not sure, you may be getting noise on the line
>that's why you may be able to load it sometimes and not others. The
>link below shows how the hookup should be.
>
>http://www.parallaxinc.com/downloads/Documentation/Basic%20Stamps/BS2%
>20rev%20F%20Schematic.pdf
>