Searching \ for '[PIC] Analog input default settings.' 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=analog
Search entire site for: 'Analog input default settings.'.

Exact match. Not showing close matches.
PICList Thread
'[PIC] Analog input default settings.'
2011\09\03@220016 by Jamie Lawson

flavicon
face
Hi,

Having made sure to set the I/O pins of a 12F683 to the digital configuration; I then proceeded to wrestle with strange yet reproducible I/O problems for a few hours.

I glanced at the data sheet and suddenly noticed the term 'comparator' seeming to glow on the page. Crap... forgot one.

I am now curious as to why the PICs analog capable pins generally power up configured in the analog function. Any ideas?

Jami

2011\09\03@222838 by Bob Ammerman

flavicon
face
> Having made sure to set the I/O pins of a 12F683 to
> the digital configuration; I then proceeded to wrestle with strange
> yet reproducible I/O problems for a few hours.
>
> I glanced at the data sheet and suddenly noticed the term 'comparator'
> seeming to glow on the page. Crap... forgot one.
>
> I am now curious as to why the PICs analog capable pins generally power up
> configured in the analog function. Any ideas?
>
> Jamie

If a pin is configured as digital, but has an analog voltage on it (ie: a voltage not near one of the supply rails) then excess 'shoot through current' could be consumed by the input gate on the chip.

-- Bob Ammerman
RAm  Systems

2011\09\04@074043 by Jan-Erik Soderholm

face picon face
Jamie Lawson wrote 2011-09-04 04:00:
> Hi,
>
> Having made sure to set the I/O pins of a 12F683 to
> the digital configuration; I then proceeded to wrestle with strange
> yet reproducible I/O problems for a few hours.
>
> I glanced at the data sheet...

Probably better to actualy *read* the datasheet.

> and suddenly noticed the term 'comparator'
> seeming to glow on the page. Crap... forgot one.
>
> I am now curious as to why the PICs analog capable pins generally power up
> configured in the analog function. Any ideas?
>

If you have a analog signal connected, analog mode is the best
startup mode.

If you have a digital signal connected, analog mode doen't do
any harm.

And besides, this is a complete non-issue of course.

What did you thought the grey box labeled "Note:" on the
"GPIO PORT" page actualy was trying to tell you ??

"The ANSEL and CMCON0 registers must be initialized to
configure an analog channel as a digital input.
Pins configured as analog inputs will read ‘0’."



> Jami

2011\09\04@135214 by Bob Blick

face
flavicon
face
On Sun, 04 Sep 2011 13:40 +0200, "Jan-Erik Soderholm"  wrote:

> And besides, this is a complete non-issue of course.
>
> What did you thought the grey box labeled "Note:" on the
> "GPIO PORT" page actualy was trying to tell you ??

Mere mortals sometimes miss things. That is what the Piclist is for.

I've answered the "why doesn't RA4 go high" question many times, it
never bothers me.

Any questions about PICs are welcome here.

Bob

-- http://www.fastmail.fm - mmm... Fastmail...

2011\09\05@000401 by xavier

picon face
I m making a battery voltage sensor using DSpic ..I m a bit stuck at this point .my input voltage from tha battery is function of duty ie if my battery voltage is 5v then I have to update tha  dutycycle. And increment tha voltage by 0.5 v. I m using a n type power mosfet as a switch (buck converter) switching freq of 1k ... I need to write a control loop. Help please ..just give me some hints to write tha control loop...
lambs become Lions

{Original Message removed}

2011\09\05@024918 by cdb

flavicon
face
::I need to write a control loop. Help please ..just give me some hints to ::write tha control loop...

Xavier,

Wasn't my reply to your main thread of any help?

If you want to control a SMPS, then the BLDC app note I listed might be of help or even look at one of the control loops that Microsoft use.

This is sample code for a Buck/Boost convert for a Pic33F
ww1.microchip.com/downloads/en/DeviceDoc/Buck-Boost%20Converter%20PI
Ctailplus%20SourceCode%20for%20dsPIC33FJ64GS610.zip

This is for a buck converter with PID control
ww1.microchip.com/downloads/en/DeviceDoc/CE021_PID_SMPS_GUI_14aug09.
zip

This is for a PWM SMPS using dsPics.
http://ww1.microchip.com/downloads/en/DeviceDoc/CE020_Std_PWM_120309.zip

This is for a dsPic SMPS with ADC
ww1.microchip.com/downloads/en/DeviceDoc/CE031_ADC_Trig_PWM_120309.z
ip

Colin

--
cdb, spam_OUTcolinTakeThisOuTspambtech-online.co.uk on 5/09/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 This email is to be considered private if addressed to a named  individual or HR department, and public if addressed to a blog,  forum or news article.

2011\09\05@033757 by Xavier Pereira

picon face
thnks a lot , I got and Idea how to write the loop .. but how can I
cause*Timer  to output PWM signal
* having a* dutycycle* of 40% and *switching frequency* of 80KHz ?
thanks a gain


On Mon, Sep 5, 2011 at 1:49 PM, cdb <.....colinKILLspamspam@spam@btech-online.co.uk> wrote:

{Quote hidden}

>

2011\09\05@034003 by Xavier Pereira

picon face
and the Loop example u gave me was of Immense help.....thanks once again
colin

On Mon, Sep 5, 2011 at 2:37 PM, Xavier Pereira <.....awesomeness.xaKILLspamspam.....gmail.com>wrote:

{Quote hidden}

>> -

2011\09\05@081211 by Forrest W Christian

flavicon
face
I'd look in the datasheets for the processor you are using.   http://ww1.microchip.com/downloads/en/AppNotes/93062A.pdf also might be of use to you - question #2 in particular.   A google search for 'pwm dspic33' also seems to reveal some good results.

-forrest

On 9/5/2011 1:37 AM, Xavier Pereira wrote:
{Quote hidden}

>> -

2011\09\06@104428 by Jamie Lawson

flavicon
face


On Sun, 4 Sep 2011, Jan-Erik Soderholm wrote:

{Quote hidden}

I agree 100%.

{Quote hidden}

Ok. I was curious since other chip families do not generally start up in analog mode (MSP430 and AVR for example).

Thanks Jan-Erik and Bob (Ammerman and Blick).

Jami

More... (looser matching)
- Last day of these posts
- In 2011 , 2012 only
- Today
- New search...