PDF files of single sided SX-28 boards
LoopyByteloose
Posts: 12,537
Hi all,
Here are three PDF files of Eagle board designs for the SX-28.
All are single sides so that the user can make these at home.
The red is a wire jumper on the top side of the board.
The blue is all the printed circuit on the bottom.
Included are the following...
A. An SX without regulator and two ribbon cable interfaces.
B. An SX with a TO-92 7805 regulator and two ribbon cable interfaces.
C. An Sx without regulator, but with the MCP3208 ADC and three ribbon cable interfaces.
One can easily use headers instead of the ribbon cable interfaces. Power is intended to be limited to low power uses.
All have an SX-key programing interface.
IF YOU LIKE WHAT YOU SEE, YOU CAN USE OR MODIFY FOR YOUR OWN USE IN EAGLE.
I USED VER 7.2XX
Here are three PDF files of Eagle board designs for the SX-28.
All are single sides so that the user can make these at home.
The red is a wire jumper on the top side of the board.
The blue is all the printed circuit on the bottom.
Included are the following...
A. An SX without regulator and two ribbon cable interfaces.
B. An SX with a TO-92 7805 regulator and two ribbon cable interfaces.
C. An Sx without regulator, but with the MCP3208 ADC and three ribbon cable interfaces.
One can easily use headers instead of the ribbon cable interfaces. Power is intended to be limited to low power uses.
All have an SX-key programing interface.
IF YOU LIKE WHAT YOU SEE, YOU CAN USE OR MODIFY FOR YOUR OWN USE IN EAGLE.
I USED VER 7.2XX
Comments
This will allow 6X on the SX28 and SX28 with regulator. And 4X on the SX28 with ADC.
It really is not worth mixing up chemicals, printing transparencies, and timing exposures for just one board at a time. My goal is to get a good transparency of each and to spend an afternoon printing 3 100mm x 150mm boards -- one of each and keep those on hand.
I still have to create an SX28 with ADC in a 4X image. But these certainly will get anyone easily started.
Do you have others for the SX48
My main focus was to get ribbon cables to provide a way to connect with breadboards and other boards that are DIY. Is that what you are looking for?
I have some 28 surface mount ... but I have a lot of 48s.
http://www.cadsoftusa.com/download-eagle/
And Eagle CAD provides a library add-on for all the SX chips at their web site for free.
My situation is that I don't have any SX SMD chips and I am freely sharing what I am developing for personal use. Why not download Eagle and do the same?
At this point, I am not sure what you want or need.
Good job on your project, there.
I will try out the Eagle CAD. What do
you use these IC s for in your projects?
Thanks.
I'll look in to Eagle CAD.
Small projects -- just about anything that a BasicStamp does can be done with an SX28 unless you need more program space. Then you might use an SX48.
They can be programed in SX/B or in SX/ASM
Senix-Ubicon was the original manufacturerer of the SX chips. I opened it and it seems to work fine. (Sadly, the Propeller.lbr at Eagle seems to need some work. But that is a separate issue.)
The SX48 and SX52 have 4 pairs of Vdd and Vss that should all be connected with nearby capacitors. It is not really easy to do all this in a single sided board. Two layers would be better.
My past experience with DIY two layer boards is alignment of the layers when exposing the transparencies is tricky. I am open to others suggestions as I have had little luck with two layers. And of course, there is an added problem of creating vias from the top to bottom layer and through-hole plating. It seems that two or more layers are best ordered from a jobber. You still can design in Eagle and provide Gerber files to jobbers. I have done that in the pass.
Do you know if there is a Ubicom library for ExpressPCB?
You say that you have done single sided SX48 boards before. I would be interested to know how. Did you rely on mostly SMD components or use through-hole components? And how did you manage the Vdd and Vss?
In Eagle, you can create vias on a single-sided board and later solder in jumper wires.
The standard ExpressPCB Schematic library only has BS1, BS2, and BS2P40 chips. It's very easy to create a new component.
You might look in the SX forums to see if there was a board made in ExpressPCB. There might be a component made.
I'm sorry it was a SX28, the SX28 was the only SMD.
There was one jumper wire.
Vdd and Vss, I just tied them together.
I can understand doing that even though the reduction in size begins to get tight.
My woes are in the power distribution requirments for 4 each of Vdd and Vss. I have considered having the backplane be Vdd and doing something fancy to connect vias that are not plated through holes. The main challenge is to create two layers of transparencies and to manage to align them perfectly during exposure so that the end results are properly aligned.
It begins to look as though I would have to build a jig of some sort to assure transparency alignment remains tight. Not impossible, but I just haven't considered how I might do so.
Even without through hole plating, there are advantages to having DIY two layers. The biggest advantage is that boards can be smaller with two layers of wiring.
Generally, I have avoided SMD projects -- but the world has changed and two-side boards with minimal SMD certainly allow one to use the SX48, the SX52, and the Propeller.
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I print my transparencies on a Hewlett-Packard Deskjet 2000 as the ink is dark enough and sticks to the transparency quite well. I previously tried Canon inkjets and the ink beaded up.
But be aware that the HP Deskjet transparencies do remain sticky and easy to smudge for quite awhile. I generally generate one and use it once without saving for repeat use.
One can put print register marks on the transparencies to align multiple layers. The register marks should be at diagonally opposite corners for the best results. The tricks to resolve are how to align while not smudging, and then how does one hold alignment during exposure?
I have to think more about this.
I can only get single-sided and can not get the photo-sensitized board here, so
I have a brother laser jet and heat-transfer with an iron, touch up with a marker, then etch. and the only SMD I had at the time of making that board (my first board with SMD's) was the SX48 and SX28.
So far, that limits you to SX-20 and SX-28 SMD chips. I will think a bit more about how I might make a single sided SX-48 for iron on, but I suspect it will be a bit large and messy. That seems to be what you really require, and likely what most DIY at home would want anyway. The double-sided solution gets fancy very quickly, and I cannot see doing it with iron on images.
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I have been spending time today on trying to create a double-sided SX-48 board that can be done DIY at home, but have not got Eagle 7.2 to behave well. I am having trouble with the use of vias to reach the second side.
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For printing double-sided boards at home....
I am pretty sure I can align the top and bottom transparancy, sandwich a cardboard insert to hold the circuit board, and then punch holes through all the layers on the outer edges to retain alignment.
This woud mean that I would also have to cut a piece of cardboard with a hole the size of the board to be exposed and have it with the same holes in the cardboard around the edges.
So I guess I would have the three layers together --- top transparency, the board jig, and the bottom transparency -- in proper alignment before I punch holes through all three layers. I might be able to use some plastic screws and nuts to assemble all three layers into a unit.
Exposure would be one side at a time, but the set up would have the board sandwiched between the two transparencies during the exposure process.
Of course, this may all need some further refinement. I will continue to think about such. I am waiting to complete a few more images. I have 5 boards here. When I get 5 transparency images, I intend to print the 5 boards on one busy day.
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I did produce a 4X SX-28 with ADC image, and it prints nicely in GIMP software, but when I convert to PDF it changes size. So I have not posted it here yet. I am trying to create all my images in PDF to make creating a transparency or iron-on very easy.... just print and use.
Individual images are easy in EagleCAD. But I transfer the image over to GIMP to make 4x and 6x images. To do that in EagleCAD you have to buy a licensed copy.
I have not been happy with the graphic quality of my 4X and 6X board images. So I had to run down what I was doing wrong.
I was using GIMP in Linux to take a single PDF image and convert it to a multiple image. GIMP is a pixel graphics editor, similar to Adobe Photoshop. And it is the wrong tool for this job.
So I switched over to Inkscape in Linux, which is a vector graphics editor and I am getting a much finer finnished image.
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In sum,
anyone can use Eagle and the .brd images are ready to properly create a single board transparency.
If you desire 4X or 6X images, you can either wait for me to post new ones here OR you can use Inkscape to create your own from a the Eagle output of single images to PDF. (I simply IMPORT the single image PDF, then COPY and PASTE to a multiple image, and finally EXPORT to a PDF or directly PRINT the .svg file.
The whole reason for this is to avoid the expense buying an Eagle license that offers a similar feature. I have found that it is more economical to print a whole 100mm x150mm or 110mm x 165mm board than to bother with cutting boards up for individual tiny transparencies.
I am sure that a comparision with my previous image will demonstrate an improvement IN THE ACTUAL PRINTED IMAGE. This is intended to be used with a 100mm x 150mm blank circuit board to simplify production and reduce wastes of material and time.
Also, the alignment of all 6 images is spot on. My technical skills have improved.
I stocked up on 20 or so, so if you need one, (DIP), let me know.
There are only 2,000 SX28AC left. I guess if I were to put together a product, I might buy 100 at a buck. Almost 100,000 of SX48BD-G.
I wonder if Robert is still selling These?
http://forums.parallax.com/showthread.php/94916-SX48-40-pin-DIP-full-kit-and-PCB-available.
Truly the sad end of an era!! I'm glad I stocked up!
I have quite a few SX-28 DIPS, that's the reason for working up these images. I also have quite a few SX-18 DIPs.
Youall may have noticed that I did produce a single-sided DIY image for the SX-48 in a separate thread. It is there to get anyone started that desires. And the more I fiddle with these images, the more I realize that I might do a bit more clean up of that.
So yes, I'd say there'll be a use for SX48 boards.