PI CHIP

[johnandles]

John....just wanting to know if the boards can be made with your method with low tolerance spacing between tracks??......without pitting.

Have you acheived this previously with this method??

Cheers Sid

No Sid, haven't tried different spacings as the boards I made where found on this site as established projects.
Either Eagle.brd or PDF,etc
Cheers

[sido]

OKay...Lets get back to the serious topic of a UNIPI!!!

Trying to layout the Ultimate UNIPI format......................

I appreciate the Moodz UNIPI V300 posted by the main man Paul. Much effort for little return from most and some questions should be adressed though, for improvement.

I have a question though for you Moodz in general.......Please dont hang me dry people........As i thought this well and is relevant to the improvement of the UNIPI for experimenters....

The UNIPI uC controlled PI is good in it's own right.....BUT..................................... ......

Can multiple TX Pulses be implemented in the TX train....where user can adjust the (parameters) timings to suit????

Example:..........Can we be able to produce the Complex TX waveform of the well known and reliable M.L waveform (SD2000) example.......

This would aid the experimenter in trying different TX Complex Timings....USER ADJUSTABLE and further Sample channnels may be used as noted to further aid the experimenter.

Basically....Moodz......IS it possible for you to generate a new code for say the PWM (1) (one of the PWM outputs) to be used as a user adjustable parameter (In Code) with a complex TX Waveform during the TX pulse...... the different TX logic parameter's if can be done...... can be user adjustable if possible to the available Chip contraints??...........Generating over say a period of 500us and repeated 3 different continiously TX pulses through the possible modified software code but user adjustable and repeated over that period of time (500us).

Similar code to the TX Train of the SD2000...but user adjustable??

Why i say this is important...... is that to experiment with complex waveforms to perform reasonably Ground Balance and elimination or experimental Waveforms relevevant in Time Domain.....then we need a code that can be able to implement a complex TX waveform where we can sample (user adjustable) as required as usual with the code already provided by yourself Moodz....but to be a user TX on Complex and adjustable TX width parameter to aid in experimenting with new GB Systems.

I love the simple UNIPI code for repetative uniform UNI PI TX Pulses.....but for complex TX parameters, these are not so good for unique and Experimental NEW GB systems if user requires them through code modification.

Just a thought there Paul.....if it can be done their through your expertize,.......... without major Modificaction to the original code (V3.00) or IC pin locations.... ....then that is a improvement in the UNIPI as a experiemental platform as a whole and will benefit most for future experiments....either utizing Differential or mono Frontends which can be used and whatever backends audios are implemented..........will aid the experimenter 10nt fold

Cheers Sid

[sido]

[ATTACH]23838[/ATTACH][ATTACH]23839[/ATTACH]

A little pitted but usable.
Still learning
Regards
John

Hi John, Great boards and unique way of producing them.

Have the idea now, how you go about making these boards and will give them a try.

Pete, Carl and the rest are correct, that the boards should be as clean as a ...... ............ .............. ........ .... ...........
to work

John....just wanting to know if the boards can be made with your method with low tolerance spacing between tracks??......without pitting.

Have you acheived this previously with this method??

Cheers Sid

[johnandles]

Thanks Pete,I haven't tried the ammonium Persulphate.
I used hydrochloric acid (from bunnings) and hydrogen peroxide (supermarket).
1:2 ratio
Never tried heating it up.
Thanks for the tip.
John

[Pete the Builder]

A little pitted but usable.
Still learning
Regards
John

They are boards you can be proud of, mate. Better than my first tries, back in the day, using Bishop Graphics and Dalton tape. And liquid rubber for the big areas.

I've found that a quick, hot etch generally (but not always) stops the pitting from happening.

You should be able to warm pretty much any etching solution and get much faster results.

I found that using ammonium persulphate (you can buy it from Jaycar relatively cheaply, in a plastic can) at 51 degrees C (which is as hot as my fishtank heater goes ) will etch a half-ounce copper board (any size) in about 2 minutes. I'm not kidding, it blew my mind. After wasting god knows how many hours sloshing around ferrick f****ing chloride in little plastic luncboxes... I swear, I nearly cried when I saw what warm persulphate could do... And it's cheaper than FeSO4 too!

If you haven't tried ammonium persulphate, you have to get some and try it. Man it's good.

Anyway... Those are really solid etches, John. You've got good edges, pretty good pad holes, nice wide IC pads, no "beaches" between tracks... Great result!

[Carl-NC]

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.

Yep, and then you clean it some more! Once clean, I'm very careful not to touch the surface and contaminate it with oily fingerprints. Done right, the results are impressive. Done wrong, it's a sad mess (done that, too).

[johnandles]

A little pitted but usable.
Still learning
Regards
John

[johnandles]

John what was the product called, just school book covering ?

Hi 6666
Can't remember the brand,Iv'e thrown the wrapper away.
It was clear vinyl,looks like contact.
The roll looks white,when unrolled it has blue squares printed on the backing paper.

@sido my printer is an old Brother,with a generic toner cartridge.
The boards turn out very usable. As pete stated,the boards have to be cleaner than a nuns...
I've made 4 boards for the Pickini project,I will post some picks when I recharge my camera.
Cheers
John

[6666]

In my case it was a coles brand here in OZ used for school book covering

John what was the product called, just school book covering ?

[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?

[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

[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.

[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

[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.

[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