SuperCarrier Cpacitors?
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I have a BS2p24 and SuperCarrier board:
http://www.parallax.com/dl/docs/prod/schem/supercarrierbd.pdf
I note that there are two 0.1uF capacitors(C3&4) in the serial connection
to the board.
On the schematic for the BS2p24:
http://www.parallax.com/dl/docs/prod/schem/Bs2p24revB.pdf
these capacitors are *not* present.
I am building a custom pc board for my BS2p24 and need to know
if these caps are necessary for normal serial comm to the
Stamp. I would prefer to delete them if possible.
Thanks,
Tom Fisher
Dallas,TX
[noparse][[/noparse]Non-text portions of this message have been removed]
http://www.parallax.com/dl/docs/prod/schem/supercarrierbd.pdf
I note that there are two 0.1uF capacitors(C3&4) in the serial connection
to the board.
On the schematic for the BS2p24:
http://www.parallax.com/dl/docs/prod/schem/Bs2p24revB.pdf
these capacitors are *not* present.
I am building a custom pc board for my BS2p24 and need to know
if these caps are necessary for normal serial comm to the
Stamp. I would prefer to delete them if possible.
Thanks,
Tom Fisher
Dallas,TX
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
because the editor deals with the DTR line properly -- it doesn't hassle
the BASIC Stamp module. But ... other programs are not as well behaved
and will cause problems (notably HyperTerminal).
The caps cost just a few cents and don't require a lot of PCB real
estate, so adding them would be a very good idea.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: tboonefisher [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rQPPrwN6Um42waayh9kqeW5U7z5DMB5NYJciZ_Qot0tRsJWtqX1FJqUmsqat1xwQOb_AdKpK5a7-unFxopKV]tboonefisher@s...[/url
Sent: Tuesday, April 13, 2004 9:37 AM
To: Support
Cc: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] SuperCarrier Cpacitors?
I have a BS2p24 and SuperCarrier board:
http://www.parallax.com/dl/docs/prod/schem/supercarrierbd.pdf
I note that there are two 0.1uF capacitors(C3&4) in the serial
connection to the board.
On the schematic for the BS2p24:
http://www.parallax.com/dl/docs/prod/schem/Bs2p24revB.pdf
these capacitors are *not* present.
I am building a custom pc board for my BS2p24 and need to know if these
caps are necessary for normal serial comm to the
Stamp. I would prefer to delete them if possible.
Thanks,
Tom Fisher
Dallas,TX
BS2 just before it programs it. Holding the
DTR line 'active' keeps the BS2 in RESET,
unless these two capacitors are there.
When they are there, DTR going active gives
a 'pulse' which does reset the BS2, but
then lets it run.
If you can control the DTR line, and force
it to stay 'inactive', then you don't need
the two caps. Note that Hyperterm is a
very stubborn program, and insists on
keeping DTR active -- so without the caps,
Hyperterm holds the BS2 in RESET.
If you disconnect DTR entirely, you won't
be able to program the BS2 in-circuit from
the BS2 IDE -- but it will run with
Hyperterm.
It's really much safer and more robust to
leave the caps in.
--- In basicstamps@yahoogroups.com, "tboonefisher"
<tboonefisher@s...> wrote:
> I have a BS2p24 and SuperCarrier board:
> http://www.parallax.com/dl/docs/prod/schem/supercarrierbd.pdf
> I note that there are two 0.1uF capacitors(C3&4) in the serial
connection
> to the board.
> On the schematic for the BS2p24:
> http://www.parallax.com/dl/docs/prod/schem/Bs2p24revB.pdf
> these capacitors are *not* present.
> I am building a custom pc board for my BS2p24 and need to know
> if these caps are necessary for normal serial comm to the
> Stamp. I would prefer to delete them if possible.
> Thanks,
>
> Tom Fisher
> Dallas,TX
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
> because the editor deals with the DTR line properly -- it doesn't hassle
> the BASIC Stamp module. But ... other programs are not as well behaved
> and will cause problems (notably HyperTerminal).
>
Thanks, Jon.
Tom Fisher
> BS2 just before it programs it. Holding the
> DTR line 'active' keeps the BS2 in RESET,
> unless these two capacitors are there.
> When they are there, DTR going active gives
> a 'pulse' which does reset the BS2, but
> then lets it run.
> If you can control the DTR line, and force
> it to stay 'inactive', then you don't need
> the two caps. Note that Hyperterm is a
> very stubborn program, and insists on
> keeping DTR active -- so without the caps,
> Hyperterm holds the BS2 in RESET.
> If you disconnect DTR entirely, you won't
> be able to program the BS2 in-circuit from
> the BS2 IDE -- but it will run with
> Hyperterm.
> It's really much safer and more robust to
> leave the caps in.
>
Thanks for a VERY nice explanation.;-))
Tom Fisher
Dallas,TX