Junebug Prob again!

[Wond3rboy]

I have applied the mods to the Junebug Clone and the Target chp. It still says that VDD detected at 4.1V. I am not using the Programmer Vdd. Supplying it externally which is 4.99v.I posted earlier about the capacitor C1 being 6.3V 22uf instead of 22uf 25v.Sometimes it gives Vpp errors and at other it doesnt. Like now it isnt giving Vpp error but i can only measure 4.5v at Vpp where it is saying 12V test passed.What should i do? Ive tried every thing!

 

[mvs sarma]

I have applied the mods to the Junebug Clone and the Target chp. It still says that VDD detected at 4.1V. I am not using the Programmer Vdd. Supplying it externally which is 4.99v.I posted earlier about the capacitor C1 being 6.3V 22uf instead of 22uf 25v.Sometimes it gives Vpp errors and at other it doesnt. Like now it isnt giving Vpp error but i can only measure 4.5v at Vpp where it is saying 12V test passed.What should i do? Ive tried every thing!

extract from pickit2 user guide.
If a short or heavy current load is detected on the PICkit™ 2 Microcontroller Programmer supplied VDD, then the user will receive an error as in Figure 2-6 and VDD will be automatically disabled.
To avoid heavy current load errors, it is recommended to keep the target current consumption below 25 mA. Large VDD capacitances should also be avoided as they slow down the VDD risetime. The allowed VDD rise time is 500 μs or less.


after this extract from an old pickit2 user guide, you can understand that the electrolytic caps should have lower value.
then, what is the inductor that you have used?
is it definitely above 500uH. if not this Vpp problem would arise. for low Vpp error, check Q6,7and 8 whether they are proper in type and mounting.
also the MosFets(Bill advised you that they are not that important and gave a suggestion how to avoid them for the time being.

many a time these Q6,7and 8 skip observation. the best would be to remove them all together. place fresh ones. . never replace a device because earlier so and so was there. a mistake done at the beginning, would be repeated. then, if you use other than 2n23904 and 3906 that follow EBC order, judge the pins order as per the device you use. For example BC547 and 557 follow CBE order as against 2n390x.
the electrolytic capacitors can better be tantalum caps instead of cheap ones that might be some times leaky.check whether the 4k7 and 2k7 chain after the diode D4 is proper and not reverse. of course i am also getting similar message of Vdd on a full version assembled and trying to debug it.
carefully record your observations and post

PS: A fully assembled pickit2 draws 46mA as it is powered. later it will draw more as the software functions and Vpp generation is ON etc, Even If the voltage is correct at 5V DC at USB, there is no wonder that 18F25450 becomes slightly warm.

 

[Wond3rboy]

Hi Sarma,i Shorted the E and D of Bs250. I got the same Vdd error except this time it was 4.8v. I used seperate supply for the Junebug clone and the target chip. Also powered the target using the programmer.The programmer was supplied externally.Did you get your correction?Thanks.

 

[Wond3rboy]

extract from pickit2 user guide.
If a short or heavy current load is detected on the PICkit™ 2 Microcontroller Programmer supplied VDD, then the user will receive an error as in Figure 2-6 and VDD will be automatically disabled.
To avoid heavy current load errors, it is recommended to keep the target current consumption below 25 mA. Large VDD capacitances should also be avoided as they slow down the VDD risetime. The allowed VDD rise time is 500 μs or less.


after this extract from an old pickit2 user guide, you can understand that the electrolytic caps should have lower value.
then, what is the inductor that you have used?
is it definitely above 500uH. if not this Vpp problem would arise. for low Vpp error, check Q6,7and 8 whether they are proper in type and mounting.
also the MosFets(Bill advised you that they are not that important and gave a suggestion how to avoid them for the time being.

many a time these Q6,7and 8 skip observation. the best would be to remove them all together. place fresh ones. . never replace a device because earlier so and so was there. a mistake done at the beginning, would be repeated. then, if you use other than 2n23904 and 3906 that follow EBC order, judge the pins order as per the device you use. For example BC547 and 557 follow CBE order as against 2n390x.
the electrolytic capacitors can better be tantalum caps instead of cheap ones that might be some times leaky.check whether the 4k7 and 2k7 chain after the diode D4 is proper and not reverse. of course i am also getting similar message of Vdd on a full version assembled and trying to debug it.
carefully record your observations and post

PS: A fully assembled pickit2 draws 46mA as it is powered. later it will draw more as the software functions and Vpp generation is ON etc, Even If the voltage is correct at 5V DC at USB, there is no wonder that 18F25450 becomes slightly warm.

Hi Sarma, I checked the entire circuit and found a flaw. Now it says that external Vdd detected at 5V. About the capacitors i have 1 electrolytic capacitor and the other .1uf cerramic capacitor(cant find a monolythic one here). I checked the pickit2 schematic and in that both of them are electrolytic. So what should i do.Also i want to ask that can i mail you my PCB design and if you find the time can you look at it since i dont find anything wrong?

How did you correct your problem?

 

[mvs sarma]

Hi Sarma, I checked the entire circuit and found a flaw. Now it says that external Vdd detected at 5V. About the capacitors i have 1 electrolytic capacitor and the other .1uf ceramic capacitor(cant find a monolythic one here). I checked the pickit2 schematic and in that both of them are electrolytic. So what should i do.Also i want to ask that can i mail you my PCB design and if you find the time can you look at it since i dont find anything wrong? How did you correct your problem?

BTW, if you did not use the Vdd pump part of the original and only assembled JUNEBUG programmer part, you need not perform the calibration step. Ensure that the electrolytic used is just 10uF at any place and 22uF after Vpp diode.
you can convert your pcb artwork and component over lay and if possible a photo of what you actually wired, into pdf and post the here itself as most members would come forward to help rather than confining to one. I asked tantalum electrolytic cap but not monolytic (? it is a new term perhaps invented by you)

 

[Wond3rboy]

Hi Sarma i have PM'd you and 3V0 with the link to my artwork since i am not too eager of posting it here( because of my classmates copying my work and showing it as thiers) . About the Monolithic thing i got the spelling wrong. It was for C1 which is supposed to be .1uf monolithic. I have made my clone using the Junebug schematic and not the PICKIT2 schematic.Should i change the caps? Also my PCB has got 4 inductors of 200uh each externaly connected so there are wires and its very hard to get a decent picture.


About Gayans remedy of supplying external power to the target. What do i do to the Vdd pin? Cause i left it open and it gave Vdd error.

 

[mvs sarma]

Hi Sarma i have PM'd you and 3V0 with the link to my artwork since i am not too eager of posting it here( because of my classmates copying my work and showing it as thiers) . About the Monolithic thing i got the spelling wrong. It was for C1 which is supposed to be .1uf monolithic. I have made my clone using the Junebug schematic and not the PICKIT2 schematic.Should i change the caps? Also my PCB has got 4 inductors of 200uh each externaly connected so there are wires and its very hard to get a decent picture.
About Gayans remedy of supplying external power to the target. What do i do to the Vdd pin? Cause i left it open and it gave Vdd error.

PMs are not meant for that.

Why you feel shy in posting on the site, even if it is wrong?
you shouldn't expect members to open links, get the file you have loaded there and serve you

you can straight attach here.

 

[3v0]

PMs are not meant for that.

Why you feel shy in posting on the site, even if it is wrong?
you shouldn't expect members to open links, get the file you have loaded there and serve you

you can straight attach here.

He is worried that other students from his school will steal his work.

I did try to open the link but could not. Either it did not like my browser or I needed to register (I will not).

In regard to PCB errors. That is one of the reasons I like Eagle in spite of the learning curve. If the schematic is right the PCB is right.

I said about all I have to say about debuggng VPP problems in my previous post.

 

[Wond3rboy]

Hi again. Here goes nothing there is no point in keeping it when it doesnt work.Here is my PCB. I am also including the Junebug CKT daigram.

This error is for Vdd even when it says there are 5v. It says it is an external voltage. Gayan said that i needed to supply target externally which i did but the error was still there cause the Vdd pin was left open.

 

[3v0]

If you are working in PICkit2 test you can ignore this

Step 1: Verify VDD
An external voltage was detected on VDD pin at 4.1 Volts.​

All junebugs will show a voltage on VDD.

 

[Wond3rboy]

That is the only error i get. If i skip this then how can i program it. I get an error of unexpected device read address in mplab. It says something about the address being incorrect.Read should be 0*19f or somthing and it is 0x00.

 

[blueroomelectronics]

0x00 usually means the programmer doesn't see a target PIC. Did you run the troubleshooting tool?

 

[blueroomelectronics]

PS the 22uf must be 16v or greater rated.

 

[Wond3rboy]

The 22uf is 25v.And this is the error i get:


Initializing PICkit 2 version 0.0.3.61
Found PICkit 2 - Operating System Version 2.32.0
Target power detected ( 4.99V)
PKWarn0003: Unexpected device ID: Please verify that a PIC16F628A is correctly installed in the application. (Expected ID = 0x1060, ID Read = 0x0)
PICkit 2 Ready

In MPLab.

 

[blueroomelectronics]

Download from my site the Inchworm Hello World poster in the Download section. This has the same ICD pinout as Junebug and shows a 16F628A example too.

 

[Wond3rboy]

Hi Bill i did it and it gave the same error when i selected the programmer. I checked the signals again and found that there was no PGC. It just wasnt coming from the 18F2550. Is that a firmware program problem? Or i have damaged the chip?

 

[mvs sarma]

Hi again. Here goes nothing there is no point in keeping it when it doesnt work.Here is my PCB. I am also including the Junebug CKT daigram.

This error is for Vdd even when it says there are 5v. It says it is an external voltage. Gayan said that i needed to supply target externally which i did but the error was still there cause the Vdd pin was left open.

please study the attached png file and the remarks therein.

 

[Wond3rboy]

Hi I get this when i start MPLab.

Initializing PICkit 2 version 0.0.3.61
Found PICkit 2 - Operating System Version 2.32.0
Target power detected ( 4.98V)
PIC16F628A found (Rev 0x8)
PICkit 2 Ready


When i try to program the 16F628A i get this error:

Programming Target (2/15/2009 1:34:18 PM)
PIC16F628A found (Rev 0x8)
Erasing Target
Programming Program Memory (0x0 - 0x9)
Verifying Program Memory (0x0 - 0x9)
PK2Error0027: Failed verify (Address = 0x0 - Expected Value 0x1683 - Value Read 0x3FF)
PICkit 2 Ready


And then the old error of expected read 0x19ff and read 0x00 comes again and it doesnt recognize the 16F628A. It recognizes it again after i restart MP Lab.


This happens with the Standalone app also.When i select read, it sometimes reads and some times sys now device found. Like in one attempt i got this(in MP Lab):

Programming Target (2/15/2009 2:00:23 PM)
PKWarn0003: Unexpected device ID: Please verify that a PIC16F628A is correctly installed in the application. (Expected ID = 0x1060, ID Read = 0x0)
Erasing Target
Programming Program Memory (0x0 - 0x200)
Programming Program Memory (0x23F - 0x640)
Programming Program Memory (0x67F - 0x6C0)
Programming Program Memory (0x6FF - 0x7FF)
Verifying Program Memory (0x0 - 0x200)
PK2Error0027: Failed verify (Address = 0x0 - Expected Value 0x0 - Value Read 0x3FFF)
PICkit 2 Ready

One thing peculiar was that when i did read multiple times from the stand alone app. I got different program memory contents.

 

[mvs sarma]

first of all there are some inconsistencies in the artwork and i really don't know whether you have considered the aspects indicated by me in the earlier post. there would be NO RESULT unless you approach systematically.

 

[Wond3rboy]

first of all there are some inconsistencies in the artwork and i really don't know whether you have considered the aspects indicated by me in the earlier post. there would be NO RESULT unless you approach systematically.

I did substitute C5 with a 10uf. The 2N7000 has its terminals correctly(checked using the diode). As for the BS250P it got damaged and now there is a short between its drain and source( I imported it and it is not available here normally). Is there any other MOSFET i can use?.Did the .1uf (ceramic) cap also. Since i am going to make the PCB again i want to know what inconsistencies have i done except the ones that you have already stated so i can correct them.I am making a new one to make every thing clear and systematic. Thanks.