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Messages - Computerman

Breakout boards / PIC18F67K90 Breakout Board

Here is a breakout board that I designed. It is specifically for the PIC18F67K90 chip, but it will work with some other 64-pin microcontrollers from Microchip. All port pins are routed to standard pinheads. Power pins have .1uF bypass caps near the chip and the power connection is bypassed by a 10uF cap. A standard HC49 crystal is also included. Schematic and board files are in Eagle format.
Project development, ideas, and suggestions / Re: PicKit 3 in Eagle format
I agree that pk2 is a better and more versitile device, but my pk2 clone quit working. Besides, I need to program 16F1507-09 series and maybe 24E or 33E series - none of which are supported by pk2. The Olimex clone (shipped) costs more than the original. The Sure clone (shipped) costs about $20 less than the original. I have most of the parts on hand already so it would still be much cheaper for me to build one.

I am not new to electronics, but I am relatively new to board design. I designed the original "CM29" through-hole version of the pk2. The thread is on I built it entirely with free samples and parts from my salvage bin. I seemed to be the only person that could get my hardware to work. It has since been reworked and perfected by others on the edaboard forum.

I understand that this project is child's play to most of you, and may not be useful to as many people as most other projects on DP, but I am surprised that nobody on this forum wanted to show of their expertise. Oh, well.
Project development, ideas, and suggestions / Update #3
Thanks, but...

Vpp/MCLR line is going all the way up to 14V so a 32V is what I'd go with.

Why a 32V if it only goes up to 14V? Would a 20V not suffice? Or even a 16V?


All tantalum caps except C23 have been changed to size 0805.

I also found a better replacement for Q4 in SOT-23, and changed D1 back to the original in SOT-23.

All parts are now original or equivalent except Q3. I think I already have the best replacement.

I believe the crystal could be replaced with a smaller one.
Project development, ideas, and suggestions / Update #2
That is one reason for wanting to build a Pickit 3. I too am interested in the same series. That and the fact that my DIY Pickit 2 crapped out on me.

UPDATE: I changed the ceramic capacitors to 0603 size and the P-FET is now IRLM6402 as in the original.

Does anybody know the current requirements for the inductor and the zeners? Or the voltage requirements for the tantalum caps? It would be nice to shrink those down some. They are HUGE!!!
Project development, ideas, and suggestions / Re: PicKit 3 in Eagle format
What's the need of single sided? Seeed charges are same for 2 layer boards, and 2layers boards are easy to route while designing.

@arupbsk, It don't need to be single-sided. I was only trying to do it single-sided because I etch my own boards using the press-n-peel-laser-printer-iron method and I can only do single-sided boards with jumper-wires. That was before I discovered Seeed. Now I prefer double-sided.

A couple more things:

The memory chips are SOIC 150mil not 208mil.
The USB connector needs to be mirrored or better yet, changed to a surface-mount type to avoid confusion.

Thanks in advance to all who help!!!
Project development, ideas, and suggestions / Re: PicKit 3 in Eagle format
I loved my Pickit 2, but Pickit 3 supports the new 16F150X chips and I think the 24E/DSPIC33E chips.

My Pickit 2 was fine for my projects and it also has some other great features (UART tool, logic analyzer), but now it is not working properly.

It would probably be only a few more dollars and much less hassle to just buy an original, but like most people on this forum, I just like to build things!!!

The reason for single-sided was that I make my boards with a worn-out HP laser printer, press-n-peel blue film, and a clothes iron. I also wanted to keep it as simple as possible for the low-budget hobbiests who must make their own boards.  That is how I built my Pickit 2. However, double-sided boards are virtually impossible to do in that manner. Enter Seeed. Problem solved.

My schematic is identical to the original in every respect except:
The MOSFET's are replaced with discretes from ON semiconductor. They could be easily changed back to the original Fairchild parts. I only did that so I could build it with samples.
Q3 and Q4 are Central Semiconductor - again so I could use samples.
I also omitted the test points.

The fuses are 1206, resistors are 0603, Ceramic caps are 0805. The tantalum caps are huge, but could possibly be shrunk to a smaller size.
Project development, ideas, and suggestions / PicKit 3 in Eagle format
I have the PicKit 3 schematic drawn into Eagle if anybody is interested in helping with the layout. It would be a big challenge to do the layout single-sided, and I am not very good doing double-sided boards.

If somebody will help with the layout, I will pay for the boards from Seeed - as long as I get 1 or 2 for me, I will donate the rest.