EasyPIC5 reset and power problems

Message

Richie800 · #1 Post by **Richie800** » 03 Jul 2009 13:21

Hello.

I have a Easypic5 board and I am having some problems and I hope someone could help me out.

The board does not reset. If I write a new program to the board, I appears to continue from where it left off before the programming started.

For example. If I write a code to have an LED on port A blink 100 times then have an LED blink on a continuous loop on port B then change the delay in which the LED on port B blinks, the program will not start from the begining with the LED on port A. It will simply continue with the LED on port B but with the different delay. Very weird. Pressing the rest button has no affect. The MCLR jumper is set correctly. The only way to reset the code is to turn off the board or disconnect the USB cable.

Also, when I apply external power and set the jumper for EXT power, the programmer LED does not illuminate. The experimental PIC does power up and executes it program but it cannot be re-programed.

The board was not always like this. I worked fine for a couple of months but now I am having problems.

Thanks for your help.

Rick

xor · #2 Post by **xor** » 03 Jul 2009 15:58

Check your Configuration settings when compiling your PIC code. MCLR can be disabled and will operate as a digital INPUT ONLY pin.

Richie800 · #3 Post by **Richie800** » 03 Jul 2009 17:23

Check your Configuration settings when compiling your PIC code. MCLR can be disabled and will operate as a digital INPUT ONLY pin.

I will try once I get home. Thank you for the quick reply.

I normally use the "Default" config setting though.

Thank you
Rick

Richie800 · #4 Post by **Richie800** » 04 Jul 2009 19:10

I checked the config parameters and I did not find any indication that MCLR is being used as an Input.

I am using a 16F876A chip.

Rick

cymb · #5 Post by **cymb** » 04 Jul 2009 19:35

reinstall everything!!???

tom

xor · #6 Post by **xor** » 05 Jul 2009 03:03

Richie800 wrote:I checked the config parameters and I did not find any indication that MCLR is being used as an Input.

I am using a 16F876A chip.

Rick

My mistake... MCLR on your PIC is a dedicated pin and does not have digital IO capability. There is not a enable/disable switch for it in the configuration settings. MCLR should reset your PIC when grounded, otherwise it is pulled high to Vdd through a pullup resistor.

cymb · #7 Post by **cymb** » 05 Jul 2009 07:32

lets see, you tried 3 more pics and all do the same thing,,,right?!!!

it worked fine b 4

something changed

who did what?

i often say we should have a video of our operations to review when
"something changes"!!

does mclr really go low?

did you reinstall all software?? this fixed some stuff for me.

is the jumper really good?

do all pic pins make contact with socket?? i have this problem as the socket metal gets deformed, looses its spring tension. all sockets today are cheap and can be suspect. you may see this with a mag lens or careful measurement, you may see different volts on pin and socket connector!

try EVERYTHING again

tom

Richie800 · #8 Post by **Richie800** » 05 Jul 2009 19:11

reinstall everything

Do you think that the software can cause a problem with the reset function and power problems?

lets see, you tried 3 more pics and all do the same thing,,,right?!!!

it worked fine b 4

something changed

who did what?

The only thing that changed was the computer the board was connected to.
All the PIC I tried were 16F876A's. I will try a 886 (different PortA coding) or a 18F2550.

does mclr really go low?

My meters battery is low but from what I can see, yes. MCLR does go low because all displays goes blank while the red reset switch is pressed.

did you reinstall all software?? this fixed some stuff for me.

Not yet

is the jumper really good?

When I place the jumper (J7) in the "I/O" position, the reset button does not turn the displays off.

do all pic pins make contact with socket?? i have this problem as the socket metal gets deformed, looses its spring tension. all sockets today are cheap and can be suspect. you may see this with a mag lens or careful measurement, you may see different volts on pin and socket connector!

Well, I am running a code that uses all the pins on A and B and they work. The OSC pins should be fine because, well the displays blink.

I believe I read somewhere that the reset switch is not connected directly to the PIC. Is that correct?

I will remove the chip from the board and test it in a circuit on a solderless breadboard with MCLR resistors and Capacitor. I will try to reset it outside of my EasyPIC5 to see what happens.

Thank
Rick

cymb · #9 Post by **cymb** » 05 Jul 2009 22:11

if i dont have a positive sure answer i use the "shotgun" ," green lite,anything goes approach!!, because i dont know " what changed"

sooo i toss out ideas

Do you think that the software can cause a problem with the reset function and power problems?

i dont know!

correct, the programmer intercepts the reset and "SHOULD" reset the pic.

im looking at a blinking led display now and as i hold reset down all leds dim and
"stick" that way till i release it.

it seems very strange that it does not reset, "IF " the pics are good and the programmer worked without errors.

try a new usb cable,,,(anything goes!!!) ,then a different port.!!

when i change ports , as i recall, the system "finds" the cable and does some magic to reconnect to the board, and yes im still tossing,,,,

tom

Richie800 · #10 Post by **Richie800** » 07 Jul 2009 00:34

Hm...........

On of the chips did not reset on the breadboard but two did. I'm not sure whats going on.

Is it possible that one of the chips damaged the programmer in some way?

BTW: I reinstalled the software and I have already tried a different USB cable and port.

I think I am going to just put up with it until it no longer works. "Drive it until the wheels fall off." :)

Thanks for all your help
Rick

igor.stancic · #11 Post by **igor.stancic** » 09 Jul 2009 08:18

Please report this on our Support Desk http://www.mikroe.com/en/support/
All you need to do is to fill out the ticket form.

Regards

Igor

Richie800 · #12 Post by **Richie800** » 11 Jul 2009 12:02

Will do

cymb · #13 Post by **cymb** » 13 Jul 2009 04:55

please do let us know about this curious problem with ?? causes?

tom
thanks

Kalain · #14 Post by **Kalain** » 18 Jul 2009 13:46

Hi,

This seems the same for me : EP5, 12F675, INTOSC, MCLR disabled (1 digital input, 1 analog input, 4 outputs), quite hard to blink some leds.
I couldn't find EP5 Schematic, This will help to understand what happen or why it doesn't happen.
EP5 manual is not so precise and not easy to follow to understand wiring MCLR : part of infos are in page 13 and also in page 19. These should be in the same page.

if i dont have a positive sure answer i use the "shotgun"

I have mine not too far......ready to use.......

Kalain · #15 Post by **Kalain** » 18 Jul 2009 16:04

cymb wrote:please do let us know about this curious problem with ?? causes?

tom
thanks

I have started another topic here :
http://www.mikroe.com/forum/viewtopic.p ... 830#104830
because even if at begining I thought it was Mclr cause, it seems this is more software problem linked with interruptions.

EasyPIC5 reset and power problems

EasyPIC5 reset and power problems

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