Picpgm PIC Detection problem (LVIP)

[jaydeep.gajjar90]

Hello Everyone !

I need to program PIC18F24J11 ic. so, I have made Picpgm USB programmer and it has been detected by PicPgm.
The Staus Bar Indicates Picpgm USB programmer and USB(FT245B).

But There is "No pic Connected" error. My PIC ic doesn't detected by Picpgm.
I have Checked All ICSP signals. all signals MCLR,PGD,PGC,PGM are working properly.(with Hardware test in Picpgm).

this PIC has normally 3.3v VDD supply. so i have not connected ICSP +5V to VDD.(Left +5V wire open.).
Also this PIC doesn't define PGM pin so i also left it open.

I have used 100 Ohm resistor in series on PGD between Programmer and Microcontroller.22pF capacitors are atteched between PGD and GND, PGC and GND. This is for filtering Purpose.

One thing i should also mention, that i use +3V Button Cell (2032, used in Computer) to provide supply to Microcontroller and i use Laptop for programming.

PicPgm gives error like below :

Pic Unknown ! Programming may fail !
Calibrating delay: 50us delay took 5403us (loop counter=703)

Please give any Suggestions/Help/Comments.

Thank in Advance.

 

[wp100]

Hello Everyone !

this PIC has normally 3.3v VDD supply. so i have not connected ICSP +5V to VDD.(Left +5V wire open.).
Also this PIC doesn't define PGM pin so i also left it open.

I have used 100 Ohm resistor in series on PGD between Programmer and Microcontroller.22pF capacitors are attached between PGD and GND, PGC and GND. This is for filtering Purpose.

Hi,

You have correctly left the programmer +5v Vdd disconnected, but have you Connected both 0v Vss, which are needed.

Vdd Core / Vcap, this pin still needs to be connected to say 470nf to ground even when programming, according to the Programming datasheet.
**broken link removed**

Your programmer to target board connection wires should be short, ideally under 150mm.


Have never used a programmer like that, but would suggest if you can program a 18F2550 chip with it , you could then make a pickit2 clone which does program many more chips without problems and also allows you to use the hardware debugger.
Countless posts on this forum for a diy pk2 clone.

 

[bigdogguru]

Countless posts on this forum for a diy pk2 clone.

That's an understatement.

There are also countless posts on this forum troubleshooting DIY PICkit clones.

BigDog

 

[jaydeep.gajjar90]

Thanks for Reply to Both !

I have connected 10uF capacitor between VDDcore and GND. and Voltage on this pin is 2.74 V.
I think it is OK as per above document.

How much is it easy to asssemble PICkit2 ? is it more reliable than PicPgm Ckt ? are there less chances for errors in case of PICkit2 ?

Again Thanks.

 

[jaydeep.gajjar90]

I also noticed one thing, that when i measure voltage on crystal oscillator pins are 1.45 v and 0 v ,when microcontroller PCB is alone.

When i atteched ICSP cable from microcontroller PCB to PicPgm USB programmer. the Voltage becomes zero on both crystal Pins.

What is Wrong ?

Please Reply.

 

[wp100]

How much is it easy to asssemble PICkit2 ? is it more reliable than PicPgm Ckt ? are there less chances for errors in case of PICkit2 ?

A diy PK2 clone is very easy to assemble, providing you stick to a circuit using standard components, not a smd one.
The biggest problem for most folk is programmig the 2550 chip, but as you have a programmer that should not be a problem.
A 680uh choke is sometimes a problem to source,depending on your area, but most other parts are very common.
You are better using a pcb to give good long term reliability.
It use Microchips free software, so does not get any better than that.


However you have not said if you have been able to program any chip with the PicPgm other than this Pic24 chip ??
Please let us know as it does help identify your problem.

I also noticed one thing, that when i measure voltage on crystal oscillator pins are 1.45 v and 0 v ,when microcontroller PCB is alone.

When i attached ICSP cable from microcontroller PCB to PicPgm USB programmer. the Voltage becomes zero on both crystal Pins.

What is Wrong ?

Assume after fitting the Vcap you have tried to program it again, same error ??


Re the crystal voltage, would not normally measure those pins with a voltmeter, a scope is really needed.
Would assume that when the programmer is connected it forces Mclre into reset so stopping various functions/ port conditions.

Possibly more important, in your icsp circuit have you got any other circuitry connected to Mclre, PGD and PGC pins ?