[PIC] DsPIC33EP32MS502 stability issue

[Jim Ruxton]

I posted some code to the Microchip forum but haven't got a response to my
question. Wondering if anyone here has any thoughts on my issue. I am using
a Microstick 2 with the above PIC and trying to generate a PWM signal. I am
using the internal FRC oscillator. I am finding that PWM only starts if I
touch pins on the PIC. Once the PWM starts I can download a new program
and PWM continues to work until powered down and restarted . This effect
seems to be independent of what the oscillator frequency is. Also I have
verified that there is a good oscillator signal whether or not the PWM is
working. Here is link to my code on the Microchip forum.
*http://www.microchip.com/forums/m1043938.aspx
<http://www.microchip.com/forums/m1043938.aspx>* Anyone ever see this kind
of behaviour?
Thanks
Jim

[p***@roadrunner.com]

Jim,

I haven't looked at your code, but issues like this are often caused by
floating pins. Unused pins should generally be set as outputs, unless they
have a pull-up or pull-down on them.

- - Bob Ammerman
RAm Systems

-----Original Message-----
From: piclist-***@mit.edu <piclist-***@mit.edu> On Behalf Of Jim
Ruxton
Sent: Monday, March 19, 2018 5:33 PM
To: Microcontroller discussion list - Public. <***@mit.edu>
Subject: [PIC] DsPIC33EP32MS502 stability issue

I posted some code to the Microchip forum but haven't got a response to my
question. Wondering if anyone here has any thoughts on my issue. I am using
a Microstick 2 with the above PIC and trying to generate a PWM signal. I am
using the internal FRC oscillator. I am finding that PWM only starts if I
touch pins on the PIC. Once the PWM starts I can download a new program and
PWM continues to work until powered down and restarted . This effect seems
to be independent of what the oscillator frequency is. Also I have verified
that there is a good oscillator signal whether or not the PWM is working.
Here is link to my code on the Microchip forum.
*http://www.microchip.com/forums/m1043938.aspx
<http://www.microchip.com/forums/m1043938.aspx>* Anyone ever see this kind
of behaviour?
Thanks
Jim
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[Jim Ruxton]

Thanks Bob. You nailed it. I needed to learn the lesson that MCC can't read
my mind and do all the work for me.
Cheers
Jim

Post by p***@roadrunner.com
Jim,
I haven't looked at your code, but issues like this are often caused by
floating pins. Unused pins should generally be set as outputs, unless they
have a pull-up or pull-down on them.
- - Bob Ammerman
RAm Systems
-----Original Message-----
Ruxton
Sent: Monday, March 19, 2018 5:33 PM
Subject: [PIC] DsPIC33EP32MS502 stability issue
I posted some code to the Microchip forum but haven't got a response to my
question. Wondering if anyone here has any thoughts on my issue. I am using
a Microstick 2 with the above PIC and trying to generate a PWM signal. I am
using the internal FRC oscillator. I am finding that PWM only starts if I
touch pins on the PIC. Once the PWM starts I can download a new program and
PWM continues to work until powered down and restarted . This effect seems
to be independent of what the oscillator frequency is. Also I have verified
that there is a good oscillator signal whether or not the PWM is working.
Here is link to my code on the Microchip forum.
*http://www.microchip.com/forums/m1043938.aspx
<http://www.microchip.com/forums/m1043938.aspx>* Anyone ever see this kind
of behaviour?
Thanks
Jim
--
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change
your membership options at http://mailman.mit.edu/mailman/listinfo/piclist
--
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist