Author Topic: PIC18F14K50 recognizing problems  (Read 3627 times)

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Offline House91320

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PIC18F14K50 recognizing problems
« on: June 09, 2013, 07:58:26 pm »
I'm having a heck of a time getting a pickit 3 to recognize a PIC18F14K50, the weird thing is, when I removed it from the circuit I was able to program it, I've included a picture of the circuit. I had to wire mcler to the pickit, so I don't think its that.
 

Offline Andy Watson

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Re: PIC18F14K50 recognizing problems
« Reply #1 on: June 09, 2013, 08:40:05 pm »
I've not used the 18F14K50, but assuming it has a similar programming interface to the 16Fxxx series there will be a five-wire interface that allows it to talk to the programming kit (PICKIT3) - two power lines, the MCLR/VPP and a pair of clock and data lines. If you trace out the details you will probably find a sixth wire. On the 16F series (and others) this is labelled as the debug and/or Low Voltage Programming pinĀ¹. This pin must not be allowed to float during programming - I believe it needs pulling down.

Edit:
1. Appears to be called RC3/PGM on the 18F14K50. Try pulling it down with ~10k.
« Last Edit: June 09, 2013, 11:01:32 pm by Andy Watson »
 

Offline Baliszoft

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Re: PIC18F14K50 recognizing problems
« Reply #2 on: June 09, 2013, 08:44:49 pm »
I am using this pic in one of my designs and it works ok. I cant see your icsp header on your picture, be sure to connect the mclr pin, too. Also disconnect the device from the usb D+ and - while programming.
 

Offline Baliszoft

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Re: PIC18F14K50 recognizing problems
« Reply #3 on: June 09, 2013, 08:52:48 pm »
+1 hint: connect the vbus to an input (with a pulldown and current limiting resistor), so your firmware can detect the usb connection.
 

Offline David_AVD

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Re: PIC18F14K50 recognizing problems
« Reply #4 on: June 09, 2013, 10:24:12 pm »
You're not trying to use the ICSP and USB connections at the same time are you?
 

Offline House91320

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Re: PIC18F14K50 recognizing problems
« Reply #5 on: June 09, 2013, 10:26:37 pm »
No, there is a usb connector soldered, but it isn't pluged into usb
 

Offline David_AVD

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Re: PIC18F14K50 recognizing problems
« Reply #6 on: June 09, 2013, 10:31:32 pm »
So you have MCLR, +5, 0V, PGC and PGD all going to the ICSP header?

I've used that chip before and had no issues with ICSP.
 

Offline House91320

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Re: PIC18F14K50 recognizing problems
« Reply #7 on: June 09, 2013, 10:32:03 pm »
yes
 

Offline David_AVD

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Re: PIC18F14K50 recognizing problems
« Reply #8 on: June 09, 2013, 10:34:37 pm »
Maybe remove the resistor on MCLR.  I think I just used the internal pull-up (or 10K at the lowest) on my design.
 

Offline Skimask

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Re: PIC18F14K50 recognizing problems
« Reply #9 on: June 10, 2013, 12:23:13 am »
And the O/P has V3.3 at the PIC before attempting to program it?
I didn't take it apart.
I turned it on.

The only stupid question is, well, most of them...

Save a fuse...Blow an electrician.
 

Offline David_AVD

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Re: PIC18F14K50 recognizing problems
« Reply #10 on: June 10, 2013, 12:28:23 am »
Oops, I missed that he was running the PIC at 3.3V, so it will be 3.3V (not 5V) on the ICSP connector of course.
 

Offline Skimask

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Re: PIC18F14K50 recognizing problems
« Reply #11 on: June 10, 2013, 12:40:10 am »
And, unlike the PK2, the PK3 likes the PIC to have power on it before it'll think about programming.
I didn't take it apart.
I turned it on.

The only stupid question is, well, most of them...

Save a fuse...Blow an electrician.
 

Offline David_AVD

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Re: PIC18F14K50 recognizing problems
« Reply #12 on: June 10, 2013, 12:59:59 am »
On my project, I used the PicKit3 to power the PIC during programming.  I don't recall if I tried ICSP with the board powered up by itself.
 

Offline House91320

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Re: PIC18F14K50 recognizing problems
« Reply #13 on: June 16, 2013, 03:48:55 am »
Solved it, headers on my pickit were dead, replaced them, and everything is working.
 


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