Need ...Pickit2 Clone mentoring .. PROBLEM SOLVED

[lou]

I need some help.  Number 1, I don't know what I'm doing.  I have built a Clone   http://cristpalma.blogspot.com/2009/05/pickit-2-clone.html   , the PIC18F2550 was not programmed by me, so accuracy is unknown . The Software being used is Microchip PicKit2 Ver 2.61.00.
I "Erase" and do a "Blank Check" (clear memory on Erase)   When I write a file to PIC16F628A, it is  written but will not verify.  After some messing around, I "Erased" the PIC16F "Blank Check" (Device is Blank), then I do a "Read Devise + Export Hex File".  When I open the exported file there are several hundred lines of code ?
I have tried a number of PIC16F chips with the same results.
 
Any help would be apperciated, Thanks, Lou

[Wizpic]

Sounds like you have got code protect active this is either set in your code or the pickit2 software, if you have got it active and when you verify you will get errors, if the hex code your seeing lokks like 00000000000000 this is code protected

wizpic

[zab]

Protected code can not be accessed.and  he said he saw many line of code in hex.
The better solution is connect programmer with pc and click on pickit2. software . On GUI go to tool tab and then to troubleshooting.this will open an other windows. with this you can verify your connection with ic being programmed. if any of the pin is not functioning you can find. For programming 3 lines (programming line to MCLR, clock and data) are used besides supply. while in reading 2 line clock and data are used just check status of all these.
clock and data toggle between 0 to 5 v while prog pin 0 to 13v.

 

[lou]

 I did fail to state that during the troubleshooting with the PicKit2 software, the software shows 11.9v, but I cannot find any voltage on the PIC2550 over 5v.  Sorry about the lack of information.  Doing some more searching on the net today, I did find an identical problem, with correction the 12v was restored and problem was fixed.  I'll do some more looking at the board components.  Any suggestion would be appreciated.
Thanks, Lou

[solutions]

Put a PDF of the schematic up

[lou]

PDF

[titi]

Hi Lou,

When I look at the schematic, something looks wrong.
The value of C5 of 47nF is too small, generaly the minimum value is 220nF, and the best value is 470nF.
So replace C5 this a 470nF.
This help to have good communication with the USB line.
The high voltage (12v) is generated by the boost power supply made with the parts: Q1 2N3904, L1 680uH, D1 1N4148 and C6 47uF.
If your board works well, you need to find between 11.8v and 13v across C6, you should find the same voltage on MCLR (across C7 or R12) when you do the check with the SOFTWARE of PICKit 2 Programmer (Tools, Troubleshoot..., Next, Next, Next, Test VPP).
It is also possible to check this voltage on the ZIF-SOCKET, by example check that there is nothing plug-in the ZIF, put a jumper on JP2, start the software test as above, you need find a voltage near 12v between PIN 20 and PIN 1 of the ZIF-SOCKET.
When you programs a PIC, don't forget to put the right jumpers according the selected PIC (example put a jumper on JP1, JP3 and JP4 for a PIC16F628A)
 
Best regards.

[solutions]

What value are you seeing on AN0, which is ADC channel 0 (or measure at pin 2 at the PIC)? This is a readout of your programming voltage.

Pin 12's output of the PIC is adjusted as a boost switching regulator according to the value on AN0. It appears (I'm guessing) they want the ADC Vref to be 5V. In that case, the code should be trying to get 897 decimal on a 10 bit ADC for 12V.

Anyway, measure, with respect to ground, either side of R8, and MCLR and report the three voltages back here. I suspect you swapped a PNP for an NPN or vice versa but the measurements will say what's going on. Since the s/w says 11.9V, I suspect you swapped Q2 and Q4 in the build...NPN for PNP ...just one of them the wrong polarity will do it.

YOU WILL NOT SEE 12V on the 2550...and better not  

[lou]

titi,
I had already replaced C5 with 100nF.  I have replaced C5 with 470nF . Nothing has changed, I'm still only getting 4.5v.
See the attachment for jumper setting, schematics, boards, etc.
__________________________________________________________________
solutions,
USB power only          R8 4.6V and 4.5V (each side), MCLR 0V.
Software 5v                No change
software 16v               R8 4.6V and 4.5v (each side), MCLR 4.6V

After looking at the schematic this afternoon 12V on 2550 is a big NO !!
___________________________________________________________________

I spent lots of time this afternoon going thru the schematic and the board.  A couple of things I did find:
With software 5V on  pin 12 0V  pin 23 .01V
With software 16v on pin 12 0V  pin 23 2.6V, pin 23 should be at 5V

Thanks to both of you for the help, Lou

[solutions]

No...pin 23 is oscillating. You are seeing the average with your meter, not the peaks of the waveform that's on that pin. Playing with the caps won't solve your problem. Put them back the way they were or you'll be troubleshooting several problems instead of the one. The original circuit supposedly works...you can tweak it later.

The 2.6V on pin 23 confirms it is running PWM or a clock-ish signal for the pump.

Either L1 is open, or Q1 is not switching (we know the base is being driven by pin23, but we don't know anything at or past the resistor).  Check the voltage on each side of the inductor....also double check the value of Q1's base resistor....

We live for the thank you button....thank you's in posts gets the ire of the mods and they mute people for it (clutter)...since you're new, something you should know.

[lou]

BINGO !!!!
After troubleshooting all afternoon, with readings changing and would not reproduce from one test to the other finally found R9 open, replaced, working like it should.
Thank for the help, Lou