Prop Proto Board Revisions - Consolidated Comments

Ken Gracey

Hey there,

I've taken another run through this thread http://forums.parallax.com/showthread.php?131077-Revision-Request-Propeller-protoboards-more-silkscreen-marking-on-bottom-of-board and consolidated the requests for revisions in the attached document.

We'll go over these suggestions internally for our next revision. The earliest we can get to it is June or so, which probably brings the new Prop Proto Board revision into inventory around September or October. We'll share the revisions with you before we go to production, too. I'm not sure who will be responsible inside Parallax but we'll be sure to ask that person to do a forum roundup to share our changes before we commit them to production.

Thanks to everybody who made contributions.

Ken Gracey
Parallax Inc.

Sapieha

HI Ken Gracey. I don't see any info on ---- Strap to disconnect RESETon USB version if needed!

Ken Gracey wrote: »

Hey there,

I've taken another run through this thread http://forums.parallax.com/showthread.php?131077-Revision-Request-Propeller-protoboards-more-silkscreen-marking-on-bottom-of-board and consolidated the requests for revisions in the attached document.

We'll go over these suggestions internally for our next revision. The earliest we can get to it is June or so, which probably brings the new Prop Proto Board revision into inventory around September or October. We'll share the revisions with you before we go to production, too. I'm not sure who will be responsible inside Parallax but we'll be sure to ask that person to do a forum roundup to share our changes before we commit them to production.

Thanks to everybody who made contributions.

Ken Gracey
Parallax Inc.

jazzed

Sapieha wrote: »

HI Ken Gracey. I don't see any info on ---- Strap to disconnect RESETon USB version if needed!

Hear! Hear! That is a useful feature.

Ken Gracey

No problem, Sapieha. We'll add it to the list. We've already assigned an internal Product Owner (Chris Savage) and he's monitoring this thread for any further suggestions. Thank you.

Ken Gracey

Bill Henning

Can you add an optional 5th (3v3, far end from GND) pin to the 4-pin prop plug header on it?

That way my SerPlug and 485Plug would work on the board...

WBA Consulting

I would suggest skimming the projects forum for pictures of proto boards in use and see how they are wired up. Some people may not submit a suggestion simply because they just used a longer than desired jumper wire, modified their design to fit the proto board, etc, but pictures will tell the story of what could have been more useful.

Phil Pilgrim (PhiPi)

Thinking in broader terms, it would be nice if the following sets of holes lined up with each other for board-stacking via simple header arrays:

1. 32212 & 32813 (Prop Proto Boards): Prototyping grid.
2. 45305 (Blank 3x4 Proto Board): Prototyping grid.
3. 28150 & 28850 (BOE): AppMod connector.
4. New Prop BOE: 20-pin AppMod-style connector.

BTW, as a separate issue, the 20-pin AppMod-style connector on the Prop BOE should also line up with the AppMod connector on the Stamp BOE. This will permit the easy implementation of a solderless protoboard, like the one requested here:

http://forums.parallax.com/showthread.php?131172-Stackable-Daughter-Board-for-the-BOE-Development-Board

Cross-product interoperability is the key. It makes the whole of the product line greater than the sum of its parts.

-Phil

localroger

I would disagree with moving the Prop off to the side. The current configuration with it in the center allows circuitry to be close to any pin. If you need more prototyping area than is there, how about a shield-like stackable extension?

I'd also suggest adding one more row of pins between the power supply and the rest of the board so that it can be salvaged when nanoizing the protoboard and used for other purposes. That is possible now, but only if you unsolder the barrel jack before hacksawing down the third full row. After separation it's a nifty little power stick and I hate wasting the components when I just wanted the SMT prop and prototyping area.

For that matter I think there would also be a market for a lower cost version that is not stuffed with the power supply components for those wo are nanoizing and embedding in another device (*cough* photo frame *cough*)

I think typical users are much more likely to be interested in NTSC out than VGA. I have never installed the VGA connector on one but I've hotwired several for video. (Of course then I went and wrote some VGA drivers and found out my company doesn't mind spending $300 for a 7-inch monitor, but I don't use protoboards for that kind of project.) I see protoboard projects as being more likely to be embedded anyway and if you want video at all you want it for debugging, and NTSC monitors work fine for that, are cheaper, and the interface uses less pins.

Phil Pilgrim (PhiPi)

localroger wrote:

I would disagree with moving the Prop off to the side. The current configuration with it in the center allows circuitry to be close to any pin.

How often is this an issue, though, and do you ever need to be close to more than the eight pins on one side?

-Phil

davidsaunders

How often is this an issue, though, and do you ever need to be close to more than the eight pins on one side?

Yes, quite often. Then again I am doing things with the Prop it was never designed for, by a long shot.

localroger

A picture being worth a thousand words...

What this shows: The vertical circuit board is an instrumentation amp cut (nanoized?) from a board I designed years ago. The orange WAGO connector by the servo holes is meant to receive a Wheatstone bridge. The instrumentation amp requires negative power so there is a 555-powered voltage inverter on the back of the protoboard. There is also a socket there that used to hold a uController.com SD card adapter. The WAGO connector on the right is meant to support off-board I2C, in this case a bunch of parallel I/O cards made by one of our manufacturers. (They have a couple of extra signals for reset and watchdogging.) Finally you can see that I hotwired video as I described earlier, and installed one jack for a PS/2 keypad. It was an experiment well worth doing even though it didn't work because of noise on the delta/sigma ADC (probably from the 555 oscillator) and the 32K program limit. I did use this to test some important code; the rest of the board I cut the instrumentation amp from implemented a fairly sharp 3-op-amp filter. With this board I proved I could emulate that filter in software, using one cog for two channels. That is a big win I have in my pocket for when I come up with a solution to the 32K problem and return to ADC land.

Cluso99

Sapieha & Ken: By placing two headers 0.1" apart for separating the USB section of the propplug and the input to the prop, you get 4 shunts to connect (or via cable) them together. This then gives you a shunt to enable the reset line, so your problem has been solved.

This is pretty much what I use on my TriBlade except the propplug and prop headers are not 0.1" apart so I use a cable and I use this to connect to each of my 3 props on the board. I only use a 3pin cable because grounds are connected. I am not sure if the grounds on the protoboard USB section should be isolated from the main pcb. Comments please??

Phil Pilgrim (PhiPi)

localroger,

Except for the sigma-delta ADC stuff I still don't see, from a signal-integrity standpoint, how an extra inch or two of trace length to the Prop could affect your app. You're already pretty spread out as it is. And if you were using a mezzanine board, you'd be adding much more trace length than that. Moreover, it kind of looks like we might get SMD pads for the sigma-delta stuff, which is really the only way to do it, due to through-hole component size and lead length. What am I missing?

-Phil

davidsaunders

Phil Pilgrim:
I do agree with you, in most cases the extra lead length does not make a difference. I ask though what happens when you have 8 Sigma Delta ADCs on a single prop? Are you suggesting that parallax provide surface mount pads for all 32 IOs? of course it is possible to overcome this also by making sure that line lengths match perfectly and the capacitance of the lines is minimal and exactly known.

localroger

Phil,

My point is that I crammed an awful lot of stuff on that board. Having the prop in the center was not a problem. And if I needed more, I'd throw your point right back at you; you could use a shield-like second storey and have all the real estate you want for prototyping. For the "a few resistors" thing the center arrangement works better and is more versatile. If you really need prototyping real estate it should be on a shield.

Cluso99

I am of a mind to agree with localroger. I think the prop placement should remain in the center.

Phil Pilgrim (PhiPi)

davidsaunders wrote:

I ask though what happens when you have 8 Sigma Delta ADCs on a single prop?

If you're doing that, you should either be designing your own PCB or using an 8:1 multiplexer and one signma-delta ADC to save pins. It would be nuts to try squeezing eight separate S-D ADCs on a proto board. My off-centering suggestion was meant to maximize the board's utility over the greatest number of expected uses by creating more usable prototyping real estate, not to encompass all the fringe cases, too.

-Phil

Sapieha

Hi Cluso. NOT correctly in same place. As it is now it is next impossible to place one 40pin's IC side of Propeller. -- At last IT Propeller need be moved one 100 mils/th to side with VGA and other connectors. Best case if it is place for 2 40 pins IC's

Cluso99 wrote: »

I am of a mind to agree with localroger. I think the prop placement should remain in the center.

Phil Pilgrim (PhiPi)

localroger wrote:

Having the prop in the center was not a problem.

I've experienced at least one instance where it was a problem, because neither of the four narrow prototyping areas surrounding the Prop was big enough. Perhaps there's some middle ground we can all agree on, though. What if the Prop were relocated slightly off-center but not at the edge. This would create one large proto area and three smaller ones. I would be satisfied with that. You?

-Phil

localroger

I would agree that it would be useful to have an area large enough for a 40-pin DIP, and a narrower prototyping area (enough for current limiting and pullup/pulldown resistors) would be OK on one or even two sides of the chip. But I like the format of the Propeller area as it is (just add a thru-hole pad for reset) for nanoization.

Sapieha

Hi Ken Gracey. It is my Base Layout -- How I will see it designed. Look on attached picture. I know that it need some adjustments AS I don't know all footprints Parallaxs use on USB and some other parts.

Ken Gracey wrote: »

No problem, Sapieha. We'll add it to the list. We've already assigned an internal Product Owner (Chris Savage) and he's monitoring this thread for any further suggestions. Thank you.

Ken Gracey

davidsaunders

I like Sepieha's sugestion on the lay out of the proto area, though I do not see where the Mini-DSUB15 for VGA would go in that.

Perhaps leave out the PS/2 and VGA space and use the VGA-PS/2 Adapter Board Kit ( http://www.parallax.com/Store/Accessories/CablesConverters/tabid/166/CategoryID/40/List/0/SortField/0/catpageindex/2/Level/a/ProductID/583/Default.aspx ) in the Proto Board Accessory kit (still making available the older version of the accessory kit).

Sapieha

Hi davidsaunders. This Base Layout Have only 16 pins header to connect EXTERNAL VGA Connector attached to Cable.

davidsaunders wrote: »

I like Sepieha's sugestion on the lay out of the proto area, though I do not see where the Mini-DSUB15 for VGA would go in that.

Ps. On picture In this post is place I will see VGA on!

Rayman

What I can't figure out is why there is no RCA jack on the protoboard... For me, TV and VGA are the real selling points of the Propeller. And, it appears to me that most people are using TV out.

So, if I were to only make one change, I'd add one or two (or maybe 3) RCA jacks.

Sapieha

Hi Rayman. Only Place I see that can have RCA is combined Footprint in place for Mouse that can fit Mouse else RCA. As mostly with RCA-TV Mouse are not used. Other Possibility To have even mouse with RCA-TV are Use KB connector that use 4 pins to KB-Mouse on same connector with splitter cable. If mouse place used as RCA-TV -- Look on attached picture for that Base Layout.

Rayman wrote: »

What I can't figure out is why there is no RCA jack on the protoboard... For me, TV and VGA are the real selling points of the Propeller. And, it appears to me that most people are using TV out.

So, if I were to only make one change, I'd add one or two (or maybe 3) RCA jacks.

Sapieha

Hi Rayman. And on this picture are even Audio connector.

Rayman wrote: »

What I can't figure out is why there is no RCA jack on the protoboard... For me, TV and VGA are the real selling points of the Propeller. And, it appears to me that most people are using TV out.

So, if I were to only make one change, I'd add one or two (or maybe 3) RCA jacks.

davidsaunders

Ok.
I do know that many use VGA, and some do not have NTSC or PAL monitors. Perhaps use some of the unused VGA pins to accomplish a couple RCA connectors for NTSC/PAL and audio, via a short cable, so as not to take any board space (this would mean having a couple of diodes on the VGA so we do not send it the NTSC/PAL or audio).

Cluso99

I like Sapieha's suggested move of the prop chip. It appears to be an excellent compromise between leaving access to the prop pins and space for larger chips.

However, I suggest rotating the prop section by 90 degrees clockwise so that P0-7 and P8-15 are closer to the larger prototyping areas.

Phil Pilgrim (PhiPi)

Ditto and ditto to Cluso99's comments.

-Phil

localroger

I will add a vote to the Sapieha reposition, even though it makes worse (*SOB*) my cool plan to salvage the power supply when nanoizing. That will still be possible, but only with desoldering the barrel connector, then sawing in from both sides on two different rows and breaking it just south of the barrel connector area. I can live with that for getting a couple of DIP40's on the proto area.

Sapieha

Hi Cluso. It is no problem to rotate Propeller -- But it give very long Traces to VGA that need in that case run bottom on Propeller. I have place to that so it is no problem BUT it is necessary?. ---- Little more to look on on my Layout idea are now in new pictures attached.

Cluso99 wrote: »

I like Sapieha's suggested move of the prop chip. It appears to be an excellent compromise between leaving access to the prop pins and space for larger chips.

However, I suggest rotating the prop section by 90 degrees clockwise so that P0-7 and P8-15 are closer to the larger prototyping areas.