MiniProp - alternative to Proto Board

Ken Peterson

Where I work, we often use the Propeller in tight spaces where the Protoboard won't fit.· I designed a smaller general-purpose PCB to solve the problem.· It is a very minimal design with prototyping area and one 3.3V regulator.· I thought I'd share the design with the group in case someone else might find it useful.· It's designed using ExpressPCB, so you have to order from them because it's a proprietary format.· If you use their Miniboard service, you can get 6 of these (3 boards, 2 per board)·for about $60, which makes them $10 each.· You'll have to do your own soldering...





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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

simonl

Very nice Ken. Thanks for sharing.

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Cheers,
Simon

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www.norfolkhelicopterclub.com

You'll always have as many take-offs as landings, the trick is to be sure you can take-off again
BTW: I type as I'm thinking, so please don't take any offence at my writing style

Whit

Thanks for posting Ken! Nice design.

Is the component list with the Express PCB schematic?

Never mind! I found them.

Do you have a picture·of your board populated?

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Post Edited (Whit) : 9/2/2008 6:47:44 PM GMT

Javalin

Hey Ken,

Thanks for sharing.

I notice you're using .15mm traces - is there any problems running that thin? Do you have a working build of the board? I've typically stuck to .38mm or so

thanks,

James

Luis Digital

The pin array is good. The Propeller proto board needs something seemed at least 16 pins.

Ken Peterson

Javelin: I just powered one up and did some quick testing with it. After I had the boards made it did seem a little thin although they were all fully formed. The longest trace on the board is about 0.3 ohms. You can thicken them up if you have concerns.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Javalin

ok - thanks Ken - i'll stick with > .25mm

James

Ken Peterson

One thing this design is missing is mounting holes.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Ken Peterson

Here's a pic of an assembled board.· It's a bit blurry.· I tried the flash on the camera, but it washed out all the detail.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

rjo_

Ken,

Very nice.

I got one of Bean's mini's... which draws power from my laptop, which makes it possible for me to work in my car, while I'm waiting for bowling to get over, etc. etc. He originally had a smaller version, and I wish I had gotten one. His current version has a very nice bread board area, so in terms of trying out ideas, it couldn't be nicer... and it has video out!!! But it doesn't have a prototyping area. So, when it comes time to making a one off prototype, I'm left wanting for something like this.

I'm finally beginning to enjoy soldering... but I don't think I could do this yet. I've looked at some of the instructional on this type of soldering and it looks really doable, but I think I'm going to wait until one of you guys comes out with one of those easy bake ovens.

What the world needs is a Prop on a board... just like yours... and nothing else.

At OBC's meeting he was showing his cut down proto board... actually pretty spiffy, but it looked terrible... all cut apart with a hack saw.

One suggestion, put some random traces between the holes. It would be fun to work with and if you didn't want a particular trace, you could always cut it.

Rich

Ken Peterson

I actually soldered the components on by hand, pin by pin. We have a stereo microscope in the lab where I work. If I didn't have that to use, I'd probably be using the DIP package.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Mike Huselton

I believe that I should try a stereo microscope. Working with surface mount components is a real pain. I recently had multiple strokes, and I think that I stereo microscope would be a great asset.

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JMH - Electronics: Engineer - Programming: Professional

Ken Peterson

As is a good soldering iron with precise temperature control and an assortment of soldering tips. I never would have attempted this with my old Radio Shack iron.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Whit

Thanks for the picture Ken!

Did you cut the heatsink off of the voltage regulator?

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Ken Peterson

Whit: It's basically a D2PAK (TO-263) package for the regulator. One can easily convert a TO-220 package to a D2PAK by cutting off the heat sink tab and bending and trimming the pins. You can use an LM317 with a couple of resistors to adjust the voltage, or you can use an LMS1585XXX-3.3 (3.3v fixed) and leave off R1 and R2. The LMS1585 is a low drop-out regulator which will allow you a lower Vin.

I formed somewhat of a heat sink by putting a few vias to a large pad on the bottom of the board.· If you need more heat sinking capability, you can enlarge the vias and fill them with solder.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

Post Edited (Ken Peterson) : 9/3/2008 6:31:01 PM GMT

Ken Peterson

Note: If you use the fixed regulator and eliminate R1 and R2, remember to put a 0-ohm jumper in place of R2. I forgot it on one board and fried the Propeller in 1 second at 12V! Oops.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup

trodoss

Ever think about putting them up for sale?· The price increased from $19 USD to $29 USD.· The downside would be that you would have to have significant numbers produced to make it cost effective.· $60 for 3 ($20/ea) would be a little steep, but I definately like the smaller size.· [noparse][[/noparse]Edit: missed that it was 6 ... $10/ea, not horrible actually, considering that it is not mass-produced]

I had thought about what it would take to do something similar with the 40 pin DIP (because I am OK at best with soldering), and maybe try batchpcb.com' service (that of course after I figure out how to use Eagle).




Post Edited (trodoss) : 9/18/2008 9:38:27 PM GMT

Sapieha

Hi Ken Peterson.

It is posible to to get only PCBs from You.

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Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer
If you don't ask you wont know
If your gonna construct something, make it·as simple as·possible yet as versatile as posible


Sapieha

Ken Peterson

Sapieha: I'm not in the business of manufacturing PCBs right now. I just came up with a design to use at work because I needed something smaller than the Proto Board, and I thought I'd share the design on the forum. I used the approach described in the last line of your signature.

In order to make it cost effective to sell them, I'd have to re-design it with an industry standard format and then have them made in much larger quantities. This is not something I have the time or inclination to do right now. But thanks for asking.

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·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

- Bjarne Stroustrup