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Intermittent working PICs

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Check your work with dmm without a pic in ZIF (even the best EE's make mistakes) , The circuit on #36 was specifically for picf2431, I had a look at 18F4520 below , I'm thinking you could add straps to cope with pinouts. not an ideal solution as it introduces opportunity for mistakes ,( I'm leaving you to sus it out ) keep in mind all the pic Vdd /Vss pins need a supply and a bypass 0.1 uF . and its not a good idea to supply I/O pins directly with Vdd .



Q are you understanding the various posts here regarding LVP ?

( Mistake ! Pin 1 is OK should have had green ink )

View attachment 91551

Hi,

As both PICs (18F 2431 and 4520) have the same connections for MCLR,PGD,PGC and PGM and the only other differences are the +v an 0V pins, I will try this wiring: See attached.

I think my Zif was wired as my orange wires (18F4520), and when the 18F2431 socket was used, the black wires 7,8 are also connected. This appears to be ok.

I've just looked at the PDF LVP, and almost get it. With a jumper on the Zif circuit, will that be ok?

Camerart.
 

Attachments

  • ZIF CIRCUIT18F 2431 4520.jpg
    ZIF CIRCUIT18F 2431 4520.jpg
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Thanks for your code. I'm sure I'm missing something, but I simply added it into a program that works and got this error: See attachment.

Your jpg showed ASM code, I suspect you have copied this code from the program of one PIC type to this program of another PIC type..
The ASM commands/instructions are different for the two PIC's! so you will get a fail to compile.

Eric.
My PICSTART+ started giving errors and finally packed up today, MPLAB cannot see it.!! Unrecognised programmed err 25
So I put the old pre upgrade pcb back into the PICstart and it will prom 16F's OK, but it cannot do 18F4520 etc.

I have just ordered a new PICStart upgrade PCB from Rapid, ~£20 [ not paying over £100+ for the full module]
 
Hi,
I am going to follow the schematic on Post#36.

Camerart.

The circuit in Post #36 will only work if you are powering your target circuit from the PICkit.
 
Your zif circuit supplies Vdd to pin 7 18F2431 = OK for 18F4520 not recommended ! (Although you really have to miss treat a PIC for it to fail ) , if you want a dual zif socket suggest below.
The LVP disabled , jumper on, and config LVP bit=0 , should be OK , the port RB5 (pin 26) will function as I/O.
( This drawing is getting a bit messy as did quick mod )
ICSP28V2.jpg
 
Dear Watchers.... I am hoping LVP is camerart s problem , I really never had much problems with PK2 or 3 really , given sloppy breadboards and mistaking pin 1 .
 
Your jpg showed ASM code, I suspect you have copied this code from the program of one PIC type to this program of another PIC type..
The ASM commands/instructions are different for the two PIC's! so you will get a fail to compile.

Eric.
My PICSTART+ started giving errors and finally packed up today, MPLAB cannot see it.!! Unrecognised programmed err 25
So I put the old pre upgrade pcb back into the PICstart and it will prom 16F's OK, but it cannot do 18F4520 etc.

I have just ordered a new PICStart upgrade PCB from Rapid, ~£20 [ not paying over £100+ for the full module]

Hi Eric,

There's a lot of information coming in for me, and I cut and paste the CODE from #52, and added it into my 18F2431 prorgam, now I see it was for John. My mistake.

Camerart.
 
Ordered PicKit3.

Camerart.
Order a 40 pin Zif socket at the same time... You will still need something to put your chip in..

For what it's worth I have no decoupling caps on my zif socket... Never had an issue!!!

BTW... I really would have bought you a pickit3..
 
Camerart . PM me your address and I will send you a spare 3M 40 pin zif got 2 not used .
 
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Hi,

Thanks for all of the kind offers.

I ordered this one: **broken link removed**

Camerart.
 
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C + Eric You realize these ebay devices are PK3 clones.
hi granda,
Yes, but all the components I have bought from China so far have been value for money and also if it does not work it can be exchanged thru Amazon.

I will let you know how it goes. [ or not ]

Great Great Granddad Eric. :rolleyes:
 
Hi Eric , seems a lots of electronics coming out of China , as you say , guess its worth a try... I presume Onshosft supports PK3 what about debug ? thats really the power of PK3 over PK2
 
Hi Eric , seems a lots of electronics coming out of China , as you say , guess its worth a try... I presume Onshosft supports PK3 what about debug ? thats really the power of PK3 over PK2

hi,
I import my Oshonsoft HEX files into MPLAB and use my PICStart+ with MPLAB as its one of the listed prommers. [ as you know the PICKIT3 is also listed ]

Its also easy to add an header to an Oshonsoft ASM file that allows to assemble and run in MPLAB

E
 
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