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PICKIT3 not programming.

camerart

Active Member
Hi,
At the moment I'm trying to program an 18F4431 PIC.
I'v tried Pickit3 programmer, and Mplab programmer with the PICKIT3.
2x differerent computers. 3x 18F4431 and 2x 18LF4620 PICS.
I've checked the voltages and the MCLR PIN has a resister to Vdd (1-10K)

So far today I've not got the offending PIC to program, but previously it was ok. On the different tests, sometimes the others will program.

I get different error reports e,g, No voltage, incorrect PIC and wrong READing of one of the BYTES, while trying to prgram.

Could it be that the PICKIT3 prograsmmer has a fault?

Any suggestions please?
Cheers, Camerart
 

Diver300

Well-Known Member
Most Helpful Member
I've had PICkit2 programmers that have lost their program. They have holes in the circuit board for programming them that align with the output pins of another one, so they can be programmed with just a 6 pin header and another PICkit2

The programming holes on a PICkit3 are closer together so some more complicated programming adaptor would be needed.

The code for a PICkit2 is available from the Microchip website, and I guess that the same applies for the PICkit3
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Is the PIC in-circuit?, if so is is powered externally or by the PK3 - the PK3 can only supply a very limited amount of power. They also seem quite prone to damage, which further limits their current capabilities.
 

ljcox

Well-Known Member
I also had problems with PK3 & had to buy another one. As Nigel said, you need to power the PIC from an external source.
 

camerart

Active Member
Hi D, N and L,
In circuit programming,
I think with the MPLAB programmer, when I set it to my VDD, of 3.3V, it gives a warning to use 5V, which I ignore, although I have accidently used 5V. I just checked the data sheet, and it appears the 18F4431 favours 5V programming. I'll re-try tomorrow.

Always externally powered with 3.3V.

Coincidently, latelly I'm experiencing problems with my laptop, which may have a bearing on things, but as mentioned I also tried the same Pickit3 on a desktop too.

If there was a problem with the Pickit3, would it sometimes work and sometimes not, as mine does?
Thanks, C.
 

Wp100

Well-Known Member
Always worth trying a different and shorter USB cable, some cheaper ones can cause problems.
 

camerart

Active Member
Hi W and I,
As the PIC needs to run with 3.3V because of peripherals, I tried powering the MCLR PIN only with a 5V (with resistor).
I also tried a short USB cable.

I normally use the Pickit3 program on this laptop, but normally I use the MPLAB one.

Can a Pickit3 go slightly problematic?

After trying lots of combinations, I think the Pickit3 needs replacing.

I presume the one I've had for years, was from China, is there an alternative?
C
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Hi W and I,
As the PIC needs to run with 3.3V because of peripherals, I tried powering the MCLR PIN only with a 5V (with resistor).
I also tried a short USB cable.

I normally use the Pickit3 program on this laptop, but normally I use the MPLAB one.

Can a Pickit3 go slightly problematic?
The output circuits can be damaged relatively easily, such as by connecting them the wrong way round, or misaligned on the pins.
 

Wp100

Well-Known Member
Always had two Pk2 because as Diver30 mentions they could loose their program, though it was possible to reload it.
Not had the Pk3 drop out that way, though not much used these days.

Looking on our UK Ebay, there are plenty of locally supplied PK3 for around GB £14, cheaper fromthe far east , but you could be waiting many weeks for one from there.

If you want a genuine Microchip programmer, seems the choice is just the new PK4 from the major electronic suppliers like RS Farnell/Newark etc.
 

camerart

Active Member
Hi N and W,
It's difficult to know what test to try, but I just tried an old Pickit2, which seemed to program, but didn't actually program correctly, and with erase, the blank check showed not erased,

I've ordered a January EDIT: PICKIT3 , but will buy a faster delivery also. The Pickit4 is a bit too expensive.

C.
 
Last edited:

camerart

Active Member
Hi G,
I'm not sure about HVP (High voltage programming) and LVP, and quite what the voltages are. My settings ar for HVP.
I think it means low as e,g,1.8V I'll have to check.

Note, the 18F4431 is not a new PIC.
C
 

granddad

Well-Known Member
HI Cam There is a file / list [ Device Support.htm ] installed with MPLABX of PICs and the various programmers, Snap is only capable of LVP (Vpp=Vdd) , but your PIC18F4431 although is LVP is not listed as supported.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Hi G,
I'm not sure about HVP (High voltage programming) and LVP, and quite what the voltages are. My settings ar for HVP.
I think it means low as e,g,1.8V I'll have to check.
LVP means programming without the 13V to switch the PIC to programming mode, and wastes some extra pins - it also requires the PIC to be specifically set to use that mode - they come as new set that way (so you have the option) but the first time you program it conventionally you turn that option off.

Note, the 18F4431 is not a new PIC.
Doesn't mean it's supported - the PK2 supports less than the PK3, and the PK3 supports less modern devices than the PK4 - and in turn the PK4 doesn't support some older devices than the PK3 does.
 

camerart

Active Member
Hi G and N,
I've been programming quite happily, then chaos!! I'm not getting any sensible programming.

Regarding HVP an LVP here is a note I found from the last time this cropped up:
I've been programming HVP ever since. I wish posted notes had dates on them, when they say old and new.

I've been playing with PK2 today, and some old 18F2520 projects, as I wanted to proceed up to 18F4431s.
Using the PK2 software, which checks which PIC is selected and sets it, also sets the voltage (which is a nice lost feature).

Without any external power it READs WRITES, but the programs don't work (could be me!)
The PK2 also find 18F4431 and 'also on my latset pcb, an 18LF4620. With power 5v to the PCB, it reports voltage error.

N's comments and very early programming remind m of the high voltage 12V needed to program them, is this true still?
C.
 

Attachments

Nigel Goodwin

Super Moderator
Most Helpful Member
Hi G and N,
I've been programming quite happily, then chaos!! I'm not getting any sensible programming.

Regarding HVP an LVP here is a note I found from the last time this cropped up:
I've been programming HVP ever since. I wish posted notes had dates on them, when they say old and new.

I've been playing with PK2 today, and some old 18F2520 projects, as I wanted to proceed up to 18F4431s.
Using the PK2 software, which checks which PIC is selected and sets it, also sets the voltage (which is a nice lost feature).

Without any external power it READs WRITES, but the programs don't work (could be me!)
The PK2 also find 18F4431 and 'also on my latset pcb, an 18LF4620. With power 5v to the PCB, it reports voltage error.

N's comments and very early programming remind m of the high voltage 12V needed to program them, is this true still?
Yes, PIC's mostly require about 12-13V for programming, unless you have them set to LVP mode.
 

camerart

Active Member
Yes, PIC's mostly require about 12-13V for programming, unless you have them set to LVP mode.
Hi N,
I don't remember using 12V apart from early Velleman programmer problems.

After trying old programmers including off circuit programming and different pics, different programmers and computers.
The last thing today was to retry the original set-up. It programmed all but one PIC of 4x, where the PCB shows no voltage. I'll check the PCB tomorrow.

I wonder if the offending PIC with no voltage could have caused the PICKIT3 to go temporarily problematic, where later it recovered?
C.
 

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