PI CHIP

[IBGold]

Hi Sido,

Save the file to a folder on your desktop you may need to unzip the files with Bit zipper first then open Designspark click open navigate to desktop and to where you put the files click on the files you want to load and click open and they will be there.

6666 have fun with them this board was originaly set up to run the Tinkerer GG Group project which I am still using while waiting for all the details so I can configure the ChipKIT UNO32 version Pete has one of my spare boards but I do not know if he has had a play with it yet there is a problem in the display section but it is an easy fix dependant on what display you use.

Regards, Ian.

[sido]

Once you open the schematic and PCB files in Designspark, click on BOM and PCB Quote, on the upper right corner. I think it would be interesting and helpful to less skilled designers, if we discuss and comment a bit on the actual parts, the prices etc. while using actual supplier's information.

Tinkerer

Hi Tinkerer. I tried doing the BOM request and half the parts were missing.
You are correct in that discussing sources and prices for the components. Most if not all can be purchased fron RS Components and Element 14. Some parts are probably already sitting in your junk box.

I created a thread in General Electronics where i have recycled alot of parts from dissued Electronics Boards. Components removed were 40 pin ic sockets, pin header's, OEM ic 4558's etc etc.
http://www.geotech1.com/forums/showt...ld-PCB-board-s

Thanks once again Ian for posting the schematic/pcb and to Stefan's well designed PCB.

Question is though, How did you get this board made up? Its double sided with vias. Has top layer copper pour and seams to be complex enough to be out of most peoples home made PCB capabilities?

How did you guys get this board made up?

Cheers Sid

[Stefan]

Hi Sid,

I made the board with the intent on using as a prototyping platform. I have added an OP amp buffer to give 5 v rail to rail swing for the analogue inputs and also buffered the digital outputs to protect the 4011. When playing it's more than probable that you will blow up something so at least the 4011 is protected to a degree.

Some of the components for the PCB design I had to build myself. There are more vias than necessary for a production run but for a prototype as you are making the boards at home the extra vias make the board more prototype friendly during construction. I have allowed enough clearance between tracks and ground planes so the board can be made at home.

I use the following sheets from Farnel ( Element14) 413-8090. Ian can give you a run down on how he made the boards. They do turn out ok.

Regards,

Stefan

[sido]

Hi Sid,

I made the board with the intent on using as a prototyping platform. I have added an OP amp buffer to give 5 v rail to rail swing for the analogue inputs and also buffered the digital outputs to protect the 4011. When playing it's more than probable that you will blow up something so at least the 4011 is protected to a degree.

Some of the components for the PCB design I had to build myself. There are more vias than necessary for a production run but for a prototype as you are making the boards at home the extra vias make the board more prototype friendly during construction. I have allowed enough clearance between tracks and ground planes so the board can be made at home.

I use the following sheets from Farnel ( Element14) 413-8090. Ian can give you a run down on how he made the boards. They do turn out ok.

Regards,

Stefan

Hi Stefan, thanks for the added info.

I thought that the missing components were due to me not having made them for designspark.
As you have created them.

Would like a basic run down to achieving similar results. I would give it a try but if i mess things up, either
i would start over again or send it out to a Forum member who offered for some board's to be made previously.
In saying this i would like to learn though.

Thank's Sid

[Pete the Builder]

Guys, I'm happy to do proper double-sided boards for you at cost. That means solder-masked (easy to solder with much less chance of accidental connections) plus silk-screened so you can just use the board itself to see where the components go. That also means if the proto works, you can safely take it out in the field. All the vias are properly made, and everything is solder-flashed so it's dead easy to solder.

The only issue might be the cost - for a single board, you're looking at (very roughly!) USD$0.65 per square inch, plus $25 setup cost, plus $24 soldermask and silkscreen. That usually works out to about USD$55 per board, one off. If say 6 people want boards, you break it down to about $15-$25 per person per board! Obviously, the more the merrier, but life doesn't usually work out that way.

What I'm proposing to do (and I'll post a proper thread/article later today) is to join in and get a board done myself for each project here, which will a) halve the price for a prototype for people like me who really can't afford the outlay, and b) have a duplicate ready if anyone needs a second board, or wants to get involved themselves. Plus, I'm about to get a whole bunch of my own boards made up, so I'm going to be able to just attach other pcb designs to that mess 'o boards, which will make it even cheaper. Details to follow. (I'm off to another specialist again. Whee. Who knew there were so many? And now I'm on the fast track!)

There are cheaper places out there (check out the back pages of Silicon Chip magazine, there are 3 or 4 Australian-based small board fabricators), but I like the quality of the guys at Futurlec. They use ETT in Thailand, and you're welcome to check them out yourselves.

Anyway, back to scheduled programming. I didn't mean to hijack the thread...
-PtB

[IBGold]

To add to Stefan's reply when doing the boards I laser print to film direct from Designspark I do two copy's of each side then glue the two prints of each side together using craft glue then I glue the two sides together on three sides making an envelope making sure in all gluing operations that all the holes are lined up perfectly then I slip in the Kalex D/Sided photosensitive board and expose to UV in my D/Sided light box I made my exposure time is one minute then I develop the boards and etch once set up it is quite easy but exposure time varies greatly dependant on the light source on my old light box which was S/Sided with fluro lights it took 16 minutes a side which was a pain.

Regards, Ian

[ODM]

I believe someone already proposed seeedstudio (yes, with 3 'e' letters) and their fusion pcb service. 25 dollars for ten pieces of max 100x100mm board for example, double sided with mask and print, and some 5-8 dollars for shipping. They don't do paneling, but you can get boards machined and drilled to shape. They do flying lead testing for a minimum 50% of the run, but for through hole parts and track widths there is practically negligible risk of process errors.

[sido]

For the scope and purpose of a experimenting, there is no need for Pro boards made to order.

Agree with IBGold and Stefan that this design can be made at home if you combine the 2 Negative Artworks to line up before exposing to UV light.

Keep the vias in check...line them up between top and bottom negative artwork and...keep some sort of corner reference for aligning the variables for the 2 layered copper tracks which should line up. providing you are combining vias and a corner reference which will do the trick

It's just a process of adding a piece of wire for the vias on both sides, after all is aligned and ready to go.

Cheer's and thank's

Sid

[Stefan]

Hi Sid,

The artwork is for a positive photo resist board. The artwork film Farnel part number that I gave is for an inkjet printer and works well as long as you make a double up the positive artwork for each side as Ian explained. I use Kinsten Positive resist boards and these give excellent results. Ian uses Kalex D/Sided Positive resist boards and his boards turn out very well also. You are able to insert IC sockets and solder in place at bottom as i have not used the top pads as connection points. The OP amp if you use it needs to be soldered in place. If not used just link out the pin to connect through. I'll attach a photo of the completed board with sockets installed just to give an idea of how the board completes.
Regards,

Stefan

[Pete the Builder]

Hey photo guys, (and anyone else who's interested), don't forget that that Press'n'Peel stuff works without needing for any exposure (or any equipment apart from an iron) at all. And for anyone without access to a laser printer, and without a physically close copy centre available, I'm more than happy to print out any designs you have. I can handle pos or neg originals, and I'll post the PnP film directly to you. Just a suggestion. (I'm an ex-photo artwork nerd, got the stained hands and lightbox to prove the pain, oh, the pain... )
-PtB

[IBGold]

Hi Pete,

I tried that Press'N'Peel stuff I bought a pack from Farnel and all I can say is I resolved to never use it again after six attempts to do one prototype board it does not work for me.

Regards, Ian.

[johnandles]

Hi Pete,

I tried that Press'N'Peel stuff I bought a pack from Farnel and all I can say is I resolved to never use it again after six attempts to do one prototype board it does not work for me.

Regards, Ian.

Hi, there is lots of internet info about laser resist iron on procedure.
I've been using cheap *** sign making sticky back stuff..In my case it was a coles brand here in OZ used for school book covering.
Think Contact, peel and stick.
All I do is print first to a blank A4 sheet of plain paper, just to locate the image on the paper.
Then cover the printed image (mirrored) with the covering material.
Same process basically as press'n'peel.
then pass that paper with the covering smoothly stuck,without wrinkles back through the laser printer.
Then Iron on to the copper clad.(board has to be totally clean!,cant understate that)
Bobs your uncle
Regards
John

[Carl-NC]

I tried that Press'N'Peel stuff I bought a pack from Farnel and all I can say is I resolved to never use it again after six attempts to do one prototype board it does not work for me.

Press'N'Peel Wet or Press'N'Peel Blue? I've used the 'Blue' with great success. Tried the 'Wet' once and didn't like it.

[sido]

Hi, there is lots of internet info about laser resist iron on procedure.
I've been using cheap *** sign making sticky back stuff..In my case it was a coles brand here in OZ used for school book covering.
Think Contact, peel and stick.
All I do is print first to a blank A4 sheet of plain paper, just to locate the image on the paper.
Then cover the printed image (mirrored) with the covering material.
Same process basically as press'n'peel.
then pass that paper with the covering smoothly stuck,without wrinkles back through the laser printer.
Then Iron on to the copper clad.(board has to be totally clean!,cant understate that)
Bobs your uncle
Regards
John

Hi John, I like this idea
What sort of printer are you using?
How well do the boards turn out?

It seem's to be the most economical way if results are good.

Cheers Sid

[Pete the Builder]

Press'N'Peel Wet or Press'N'Peel Blue? I've used the 'Blue' with great success. Tried the 'Wet' once and didn't like it.

Me too. The wet stuff just made a damn mess. I wasted half the pack, and binned the other half.

For anyone interested, the trick with PnP is temperature - and über-clean boards.

When I say 'clean', I mean "water runs off it like a duck's donger" clean. You scrub the copper with plain steel wool and soap. Don't bother with sprays or chemical cleaners. When you've finished, the board will shine so clearly that any dirty spots or grease from a finger stands out like dog's balls. You drop some water on it and it stays in a drop - it doesn't wet the surface.

This takes nothing but elbow grease and a good wrist action, sailor!

The iron must be steam-free - tip the water out if it has any. Then set it to "Cotton" for half an hour to dry out the tanks. Then, get any cheap non-contact thermometer and turn the temperature down to exactly 126 degrees Celcius (those living in Neanderthal countries can convert to their own barbarian scales) . It has to stay there for at least 2-3 minutes. Once it's there, just get a fine-tipped marker and place a dot on the dial. THen you can always pick the perfect temp every time.

Oh yeah - some irons have very little heat mass. That means they're fine for thin clothes, but terrible at staying at the same temperature when they're pressed on to a big sheet of copper-clad FR4 fibreglass!

Big, old irons work beautifully. Try St Vinnies or your local op shop for old irons in working condition. That's what I use!

Pristine, beautiful copper, and a big, hot old iron, and the job is too easy. I swear, I did it the hard way, then experimented, then when I figured the temperature - 126 Celcius - and the board was clean, hell, I can get an entire A4 sheet done, corner to corner, perfectly, every time.

Oh, yeah, and you have to peel it off when it's absolutely cold. Running-water cold. Pick up one corner, and gently, gently peel it away, nice and slow. Sounds weird, works every time.

The only time I have any problems are with heat (the missus' new iron was crap at holding heat, I had to buy back our old one!) and with board cleanliness. Don't even breathe on the board. That's how clean it needs to be.

I hope this was a) fun and ii) useful to someone, anyone.

-PtB

P.S. With a reasonably good laser printer, good quality toner (not cheap refills, pay a few dollars more, you cheapskate! ) and bog-standard PnP, you can print to 6 thou clearances with just a little easing up on the pressure. That means you can design, etch, and solder in an FPGA if you need to, or an ARM3 core Arduino chip (not module!) - at home. How cool is that?