Searching \ for '[EE]: How low can you go?' 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/index.htm?key=how+low+can+you
Search entire site for: 'How low can you go?'.

Exact match. Not showing close matches.
PICList Thread
'[EE]: How low can you go?'
2001\02\14@141314 by Barry Gershenfeld

picon face
We just fired up a board with a 12C671, and of course it didn't
work.  How you debug a chip like that, I think you have to
do it by staring at it...(I'm gonna look at the C compiler
output)

What bothered me above all is that the output pin showed 0 volts.
I mean 0.000 volts.  Is something wrong with this picture?  Is
there a technology (FET, etc.) that would give a real low
state of 0 volts?  It's not shorted (we measured several K
to ground) and the PIC has power.

Barry

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email spam_OUTlistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2001\02\14@142744 by James Paul

flavicon
face
Barry,

Did you remember to make the pins Digital I/O?  They power up as
analog and inputs.  Of course, this doesn't explain the 0 volts.

                                          Regards,

                                            Jim


On Wed, 14 February 2001, Barry Gershenfeld wrote:

{Quote hidden}

jimspamKILLspamjpes.com

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2001\02\14@153659 by Dal Wheeler

flavicon
face
Which pin?  Default as ADC in maybe?
----- Original Message -----
From: Barry Gershenfeld <EraseMEbarryspam_OUTspamTakeThisOuTZMICRO.COM>
To: <PICLISTspamspam_OUTMITVMA.MIT.EDU>
Sent: Wednesday, February 14, 2001 12:07 PM
Subject: [EE]: How low can you go?


{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email KILLspamlistservKILLspamspammitvma.mit.edu with SET PICList DIGEST in the body


2001\02\14@175946 by Barry Gershenfeld

picon face
>Which pin?  Default as ADC in maybe?

I appreciate all the suggestions I've recieved so far.  I asked
a guy at lunch the original question and he says there is
output logic that will go to 0.0 volts.   He didn't elaborate.

I'm currently researching the various configuration settings and
the results in the hex file.  I'll be looking for the ADC or
ADDCON stuff as well.

See my next message about "Config word in 12C671"

Barry

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2001\02\15@031029 by Roman Black

flavicon
face
Barry Gershenfeld wrote:
>
> We just fired up a board with a 12C671, and of course it didn't
> work.  How you debug a chip like that, I think you have to
> do it by staring at it...(I'm gonna look at the C compiler
> output)
>
> What bothered me above all is that the output pin showed 0 volts.
> I mean 0.000 volts.  Is something wrong with this picture?  Is
> there a technology (FET, etc.) that would give a real low
> state of 0 volts?  It's not shorted (we measured several K
> to ground) and the PIC has power.

Could be quite normal for the output pin to be that
low depending what current it is sinking. Very low
currents sunk give very low sat voltages.

If you want to test the output pin, add a 1k pullup
resistor to 5v. This will make it sink about 4-5mA.
The low voltage will then be about 0.3 - 0.4v typical,
(datasheet claims 0.6v max for 8.5mA sunk).
-Roman

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


2001\02\15@164604 by Peter L. Peres

picon face
0.000 volts showing Kohms to GND looks like a PIC pin that is driven
permanently low and tristated with some duty cycle or other imho. Try to
hook up a pullup resistor and use a scope on this pin. Small FET outputs
do give 0.000 volts and a few kohms when measured. Typical examples are
outputs from CMOS CD4xxx(x) series logical chips. This is a feature by the
way ;-).

Peter

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


More... (looser matching)
- Last day of these posts
- In 2001 , 2002 only
- Today
- New search...