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I checked again the polarity of all the MOSFET's. They are all wired properly.
I discovered that my mutlimeter is faulty. Using a different meter, I am able to calibrate Vdd at 2.5V to 4.7V within +/-.1V.
USB voltage on my computer is 5.0V.
Still says "Unexpected voltage on Vdd."
Replaced the MOSFET's and checked the polarity very carefully. It still reads an "Unexpected voltage on Vdd" with no cable attached. Used a different cable about 3 inches long. It now works properly with 16LF819 and 16LF833A, but It still reads an "Unexpected voltage on Vdd." It did not work at...
I have updated Eagle files.
All parts are now original or equivalent except Q3.
Resistors and ceramic caps are 0603.
Tantalum caps (except C23) are 0805.
The fuses are 1206.
The crystal could be changed to a smaller one.
The sizes for all but the IC's could be scaled back up to make it easier...
Thank you very much, Sarma!
Btw, I replaced all of the diodes and the op-amp. Still no-go. Will try new MOSFETS next. I will then a different 2550 if that don't fix it. I don't think that is the problem, but it is worth a try. Stay tuned!
Oops! Uploaded the wrong file!
MOSFET's and VDD_USB are corrected.
I didn't get the "Vdd short" messages or problems with L1 heating, so I left out the 10ohm series resistor.
I used the BC639/BC640 because I am on a VERY low budget, and I got them as free samples from ON Semiconductor. Same...
For those interested, I have a revised and corrected version using my original parts. I made new library entries for the MOSFET's and fixed the connection so the LED and PTG work properly. The MOSFET's are in TO251AAV (I-PAK), which is not much bigger than TO-92. I only have the schematic...
PicKit 2 is built on a circuit board.
PicKit 2 has .1uf ceramic cap bypassing the power pins on the 2550 (not in the schematic).
Crystal and caps are almost touching the 2550.
The intended target is a PIC12F675 on a breadboard. Have also tried a PIC16F819 and it would see it sometimes, but...
I built the original hardware - NOT Nishal's hardware. It has wire jumpers all over, but it worked once I got the mosfets wired properly.
I am using PicKit2 2.61 software on a breadboard, and powering the pic with the PicKit 2.
I tried the UART tool in the software. All appeared to be ok, but...
Greetings, all!
I am having a problem with my PicKit 2. It is my design as in the thread: https://www.edaboard.com/threads/118478/.
It worked flawlessly once I got the mosfets properly wired. I have since used it many times with several different pic's with no problems. Now it don't see any...
Thank you JayantD.
I know I don't need to, but I use junctions on every connection mainly to make sure they are connected properly when I check the nets. My design does have erc errors, but they are all the result of either unused pins on IC's, or because some IC's use GND, and some use Vss and...
As promised, here is the schematic and board files with the original Microchip and Atmel parts for U3 and U4. The layout is NOT complete, but included for reference.
Good idea. I only chose the SST part because I have them on hand. Since I have not built it yet (I have been busy packing, moving and unpacking), I will change it in the .sch/.brd files and repost. I will also change U3 to the Microchip part to match the original. I thought that they were both...
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