Searching \ for '[PIC]: Reset PIC using Com Port' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/ios.htm?key=port
Search entire site for: 'Reset PIC using Com Port'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: Reset PIC using Com Port'
2002\06\30@013118 by PSL

flavicon
face
part 1 203 bytes content-type:text/plain; (decoded 7bit)

Hi all

currently I am using the circuit in the attach file to reset my PIC by com
port.
Just to check is this method advisable and is there any better way.

regards



part 2 15715 bytes content-type:image/jpeg; (decode)


part 3 105 bytes
--
http://www.piclist.com hint: To leave the PICList
spam_OUTpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu


2002\06\30@014610 by Joe Farr

flavicon
face
Well,

I'd place a current limiting resisor on the base of the transistor.
Also, did you mean to use the RTS (Request To Send) pin as a reset ?




-----Original Message-----
From: PSL [.....pslnKILLspamspam@spam@STARHUB.NET.SG]
Sent: 30 June 2002 06:30
To: PICLISTspamKILLspamMITVMA.MIT.EDU
Subject: [PIC]: Reset PIC using Com Port


Hi all

currently I am using the circuit in the attach file to reset my PIC by com
port.
Just to check is this method advisable and is there any better way.

regards

--
http://www.piclist.com hint: To leave the PICList
.....piclist-unsubscribe-requestKILLspamspam.....mitvma.mit.edu


2002\06\30@023459 by PSL

flavicon
face
Yes
I have use the RTS PIN to reset it
RX and TX Pin are used.
Will it have any problem in power consumption?

Regards


----- Original Message -----
From: "Joe Farr" <EraseMEjoe.farrspam_OUTspamTakeThisOuTKCSL.UK.COM>
To: <PICLISTspamspam_OUTMITVMA.MIT.EDU>
Sent: Sunday, June 30, 2002 1:45 PM
Subject: Re: [PIC]: Reset PIC using Com Port


Well,

I'd place a current limiting resisor on the base of the transistor.
Also, did you mean to use the RTS (Request To Send) pin as a reset ?




{Original Message removed}

2002\06\30@024120 by Joe Farr

flavicon
face
Without a current limiting resistor on the base of the transistor, you stand a good chance of damaging it or perhaps the gate on the MAX232. Try it with a 1K resistor.


-----Original Message-----
From: PSL [@spam@pslnKILLspamspamSTARHUB.NET.SG]
Sent: 30 June 2002 07:33
To: KILLspamPICLISTKILLspamspamMITVMA.MIT.EDU
Subject: Re: [PIC]: Reset PIC using Com Port


Yes
I have use the RTS PIN to reset it
RX and TX Pin are used.
Will it have any problem in power consumption?

--
http://www.piclist.com hint: To leave the PICList
RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu


2002\06\30@024748 by PSL

flavicon
face
Thanks for the infor
----- Original Message -----
From: "Joe Farr" <spamBeGonejoe.farrspamBeGonespamKCSL.UK.COM>
To: <TakeThisOuTPICLISTEraseMEspamspam_OUTMITVMA.MIT.EDU>
Sent: Sunday, June 30, 2002 2:41 PM
Subject: Re: [PIC]: Reset PIC using Com Port


Without a current limiting resistor on the base of the transistor, you stand
a good chance of damaging it or perhaps the gate on the MAX232. Try it with
a 1K resistor.


-----Original Message-----
From: PSL [RemoveMEpslnspamTakeThisOuTSTARHUB.NET.SG]
Sent: 30 June 2002 07:33
To: PICLISTEraseMEspam.....MITVMA.MIT.EDU
Subject: Re: [PIC]: Reset PIC using Com Port


Yes
I have use the RTS PIN to reset it
RX and TX Pin are used.
Will it have any problem in power consumption?

--
http://www.piclist.com hint: To leave the PICList
EraseMEpiclist-unsubscribe-requestspammitvma.mit.edu

--
http://www.piclist.com hint: To leave the PICList
RemoveMEpiclist-unsubscribe-requestEraseMEspamEraseMEmitvma.mit.edu


2002\06\30@051534 by uter van ooijen & floortje hanneman

picon face
> Just to check is this method advisable and is there any better way.

- T + R (one transistor less, one resistor more):
http://www.voti.nl/wloader

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

--
http://www.piclist.com hint: To leave the PICList
RemoveMEpiclist-unsubscribe-requestspam_OUTspamKILLspammitvma.mit.edu


2002\06\30@065429 by Bob Ammerman

picon face
Actually, a proper RS232 driver has a guaranteed minimum source impedence,
which would eliminate the need for the resistor. However, the resistor is
_very_ cheap insurance.

Bob Ammerman
RAm Systems


----- Original Message -----
From: "PSL" <RemoveMEpslnTakeThisOuTspamspamSTARHUB.NET.SG>
To: <EraseMEPICLISTspamspamspamBeGoneMITVMA.MIT.EDU>
Sent: Sunday, June 30, 2002 2:46 AM
Subject: Re: [PIC]: Reset PIC using Com Port


> Thanks for the infor
> ----- Original Message -----
> From: "Joe Farr" <RemoveMEjoe.farrKILLspamspamKCSL.UK.COM>
> To: <PICLISTSTOPspamspamspam_OUTMITVMA.MIT.EDU>
> Sent: Sunday, June 30, 2002 2:41 PM
> Subject: Re: [PIC]: Reset PIC using Com Port
>
>
> Without a current limiting resistor on the base of the transistor, you
stand
> a good chance of damaging it or perhaps the gate on the MAX232. Try it
with
> a 1K resistor.
>
>
> {Original Message removed}

2002\06\30@091144 by Olin Lathrop

face picon face
> currently I am using the circuit in the attach file to reset my PIC by com
> port.
> Just to check is this method advisable and is there any better way.

I don't like the MAX232 connected to the base of the transistor directly.
There should be a base resistor to limit the base current.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: To leave the PICList
spamBeGonepiclist-unsubscribe-requestSTOPspamspamEraseMEmitvma.mit.edu


2002\06\30@091424 by Olin Lathrop

face picon face
>>
Without a current limiting resistor on the base of the transistor, you stand
a good chance of damaging it or perhaps the gate on the MAX232. Try it with
a 1K resistor.
<<

I like a 10Kohm resistor better.  There is no need to draw nearly 5mA just
to turn on the transistor.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: To leave the PICList
KILLspampiclist-unsubscribe-requestspamBeGonespammitvma.mit.edu


2002\06\30@092044 by Olin Lathrop

face picon face
> Actually, a proper RS232 driver has a guaranteed minimum source impedence,
> which would eliminate the need for the resistor. However, the resistor is
> _very_ cheap insurance.

Are you sure this is true for the 5V side where he hooked it up?  It sounds
a little odd, but I don't have the spec sheet in front of me right now.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: To leave the PICList
EraseMEpiclist-unsubscribe-requestspamEraseMEmitvma.mit.edu


2002\06\30@155039 by uter van ooijen & floortje hanneman

picon face
> Actually, a proper RS232 driver has a guaranteed minimum source impedence,
> which would eliminate the need for the resistor. However, the resistor is
> _very_ cheap insurance.

But that referes to the RS232 side, and the transistor is on the other side!
But (re my earlier response) why use a transistor at all?

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

--
http://www.piclist.com hint: To leave the PICList
@spam@piclist-unsubscribe-request@spam@spamspam_OUTmitvma.mit.edu


2002\06\30@171000 by Brent Brown

picon face
Looks good (except for the base resistor mentioned several times
already). May I offer the following simplification though: use a
diode in place of the transistor, anode to MCLR, cathode to MAX232
output. The reason you are using a transistor in the first place is
simply to achieve a logic "OR" of the two possible reset signals.

Pin 7 (RTS) is a good choice I think. (RTS = Reset The Sucker?). I am
using the same pin because I run Shane Tolmies bootloader in
conjunction with Petr Kolomazniks downloader, both from:
www.workingtex.com/htpic/PIC_bootloader.htm
The downloader program generates a reset signal on RTS, which means
you don't have to manually reset or power down the micro to initiate
the bootloader.






> Hi all
>
> currently I am using the circuit in the attach file to reset my PIC by
> com port. Just to check is this method advisable and is there any
> better way.
>
> regards
>
>

--
Brent Brown, Electronic Design Solutions
16 English Street, Hamilton, New Zealand
Ph/fax: +64 7 849 0069
Mobile/txt: 025 334 069
eMail:  spamBeGonebrent.brownspamKILLspamclear.net.nz

--
http://www.piclist.com hint: To leave the PICList
.....piclist-unsubscribe-requestspam_OUTspammitvma.mit.edu


2002\06\30@181748 by Olin Lathrop

face picon face
> But (re my earlier response) why use a transistor at all?

So it's OK to short MCLR to ground with a pushbutton switch that was also
shown on the schematic.  The transistor is required unless the MAX232
5V-side output is open collector, which I didn't think it was.  I don't have
the spec sheet in front of me right now.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: To leave the PICList
TakeThisOuTpiclist-unsubscribe-request.....spamTakeThisOuTmitvma.mit.edu


2002\06\30@201932 by Jinx

face picon face
> > But (re my earlier response) why use a transistor at all?
>
> So it's OK to short MCLR to ground with a pushbutton switch that
> was also shown on the schematic

It's recommended to have a series resistor (220R) into MCLR, and
if using a reset switch to ground MCLR through 100R. Also a cap
(eg 10n) from MCLR to ground to ensure that MCLR reaches Vcc
after the Vcc pin does ( if POR function is not used - DS00007 )

--
http://www.piclist.com hint: To leave the PICList
TakeThisOuTpiclist-unsubscribe-requestKILLspamspamspammitvma.mit.edu



'[PIC]: Reset PIC using Com Port'
2002\07\01@043502 by uter van ooijen & floortje hanneman
picon face
> > But (re my earlier response) why use a transistor at all?
>
> So it's OK to short MCLR to ground with a pushbutton switch that was also
> shown on the schematic.  The transistor is required unless the MAX232
> 5V-side output is open collector, which I didn't think it was.  I don't
have
> the spec sheet in front of me right now.

(as used http://www.voti.nl/wloader )

Shorting MCLR with a switch is possible with a resistor from the MAX to the
PIC. An extra resistor between the MAX and the Vcc is advised to guarantee a
MCLR Voltage that is high enough.

Wouter van Ooijen
--
Van Ooijen Technische Informatica: http://www.voti.nl
Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\07\02@105436 by Bob Ammerman

picon face
> > Actually, a proper RS232 driver has a guaranteed minimum source
impedence,
> > which would eliminate the need for the resistor. However, the resistor
is
> > _very_ cheap insurance.
> > Bob Ammerman
>
> Are you sure this is true for the 5V side where he hooked it up?  It
sounds
> a little odd, but I don't have the spec sheet in front of me right now.
>Olin

Well, I am not 100% sure, but I'd say a good 99 44/100%. If nothing else so
that the signal can be considered power-limited in the electrical code
sense. (Hm... 12V at big amps and a short-circuit can make a nice fire).

Bob Ammerman
RAm Systems

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...