UPDATED: PropBoard for Review(and sale!)

Philldapill

I've been designing a compact, "plugable" propeller board for a few weeks now, and would like some feedback and review of it. I've fried way too many propellers because of careless mistakes with jumper wires on a breadboard. I've gotten tired of fiddling with all these wires and loose parts, so I've had enough of it. I can make my own PCB prototypes, and have done so for a while now. However, I can only get a certain precision and scale with my methods, so I'd like to get a few of my boards fabricated by a professional PCB maker.

I'm sure a few of you others have also fried a chip or two, and to make this cost effective, I'm going to get about 20 of these boards made. I'll probably keep 3 or 4 of these boards for my own purposes, and I'd like to sell the rest. I've attached a picture of the board. It includes a single PS/2 port for a keyboard or mouse. I've always wondered why the protoboard has 2 of these. I've never had to use a mouse and keyboard at the same time, but whatever... Anyway, it also has a 2.5mm DC power jack for a walwart. The crystal will be removable so that you can replace it with whatever you want. This is specifically a DIP chip board. This is to make it a little easier to just replace the chip by dropping a new one in, rather than trying to solder the SMD chip, like on the protoboard. The EEPROM is also DIP, even though it seems rare to blow this one. One note about the picture - I've added a couple of jumpers to the clock and data lines of the PS/2. This is so that if you are not using it, you can take the jumpers off, and there will be no problems if you are using pins 26 and 27 for something else.

One final note, this board is meant to be·"plugged in" to a breadboard OR, you can put female headers in place of the male headers and make it a board that you plug only the wires you want, into it.

If anyone is interested in a board, let me know. And please, be mean in your critiques! This is one of my first REAL boards that I will be making and I want to get it totally right!·[noparse]:)[/noparse]

EDIT: By the way, the dimensions are 2" x 3.4".

Post Edited (Philldapill) : 12/31/2008 11:16:07 PM GMT

Oldbitcollector (Jeff)

Composite (TV) video head would make it nearly perfect. [noparse]:)[/noparse]

Nice work!

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

Philldapill

Yeah, my thoughts too! I've beat my head against the wall, however, trying to make it fit somewhere is going to be tough. I was thinking of the lower right corner, but that would make the board bigger - more cost. But hey, I'll make another version with one on it. By the way, if you want to assemble one of these yourself, there are only 3 jumper wires that need soldering. I can supply all the parts(minus propeller and eeprom) for a total of about $10-$12(shipping in the US included in that price). Still, less than a propeller chip, but it'll probably save a couple from being fried in the first place!

Forrest

Looks good. I'd only make one minor change - the circuit to I/O Pin 27 runs too close to the edge of the board - it might get sliced off when the board fabricator depanelizes the board. A good rule of thumb is to keep the traces no closer than 0.050 in from the edge of the board. So I'd bump the size of the board up to 2 x 3.5 in.

Oh, forgot to mention I'd like one of those boards also.

Philldapill

Yeah, good thinking, Forrest. I've changed it to fix that problem. Oh, and I think I've found a way to add Composite on pins 20-22. VERY compact, but fits nicely.

So, now, here are the features:

- I/O pins 0 through 27, plus regulated 3.3V and Ground are all out front able to plug into a small 30 row breadboard(or any other larger one) perfectly
- 1 PS/2 port on pins 26 and 27, with the ability to "disconnect" it via 2 jumper pins, allowing zero interference on these pins when they are used for another purpose
- 1 Composite TV output on pins 20-22, again with the ability to "disconnect" via 3 jumper pins
- 5V and Vin are available via female pin headers on front of board
- Propeller and eeprom are in DIP packages for easy removal and replacement
- Input power is supplied via a 2.5mm DC power jack(inside barrel plug is negative, outside is positive)
- Costs less than a propeller itself, but saves chips by no loose prototyping wires!

Hadrian_x

Looks fantastic. Can't wait for production to begin. Love to get my hands on one of these as soon as it's ready!

parts-man73

Why the odd power connector? 2.1mm center positive is what most users will have on hand.

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Brian

uController.com - home of SpinStudio - the modular Development system for the Propeller

PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!

SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board

Whit

Is there enough room between the PS/2 and PropPlug connection pins?

This looks like a great board and I like the improvements you've made.

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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) : 12/31/2008 3:04:37 PM GMT

John Abshier

I would like mount holes (for #4 screw).

John Abshier

mikediv

Philldapill·I would also be interested, is there anyway to add a few 7 segment displays or better an assembled interface for an LCD just a thought

Paul Sr.

parts-man73 said...
Why the odd power connector? 2.1mm center positive is what most users will have on hand.

I agree!

Everything on the bench is 2.1, CENTER Positive. 2.5 center negative would be a nuisance...

Philldapill

mikediv,
I'm trying to keep this board simple enough for the most common items. An LCD is a common item, but with the TV plug I'm adding, an LCD seems a little redundant, not to mention allllll those pins it would need.

John,
Do you know what diameter holes #4 are in inches? Doesn't have to be exact, since I can always make the wholes slightly larger to make sure the screws fit. Adding these holes will make the board a good half inch bigger on each side... Plus, I'm adding the TV composite plug on the bottom right corner, so the screws may get in the way if you want to use them AND the TV.

Whit,
THANK YOU for a keen eye. I was only taking into account the actual female headers on the prop plug when I was positioning the PS/2. I forgot that the PCB of the prop plug is slightly wider. I've corrected this now.

Brian - the man of propeller PCBs,
I was under the assumption that the 2.5mm plug was the common type... As for the polarity, if the opposite polarity is much more common, then that is an easy fix. Please let me know which polarity is more common - the one I have on the board, or the opposite.

Everyone,
To keep the cost down for these boards, I'm shooting to get at least 20 boards made. I'm keeping 3 for myself, so that means I'll need to get orders for 17 more. I'm selling these at cost, for the most part, with the more specific components included. These components are: the two regulators, the header pins in front, the header pins for the prop plug, the reset switch, and the power plug(just tell me what kind you need). As for the video plug, PS/2 and other non-essential resistors, just let me know if you want those too for a buck extra(at cost).

Thanks guys for all the feedback!

Ed Parsons

Philldapill,

Major diameter on #4 screws is .112", clearance for tight fit is .116" and for loose fit is .128"

By the way, the board is looking great. When will you be posting the revised layout with the changes?

Ed

Forrest

I checked a couple of the DC bricks in my collection and nearly all are 2.1 mm, center positive.

(2) mounting holes works fine for me - looks like there's some room on the side with the PS2 connector.

John Abshier

0.125 inches is a good size for #4 screw. I also vote for 2.1mm center positive power.

John Abshier

parts-man73

All of Parallax's PCB's are center positive too, and all of mine too.

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Brian

uController.com - home of SpinStudio - the modular Development system for the Propeller

PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!

SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board

Philldapill

Ok, I made some changes to the board.

- Added Qty. 4, 0.125"(#4) holes on the corners. The spacing is 3.4" x 1.75"
- Changed the 5V and Vin access
- Added a crude TV Adapter which is a serpate board with resistors/RCA plug on it. This can be plugged in and should be pretty structurally stable.
- Fixed the spacing between the PS/2 and Prop Plug pins
- Changed the DC Jack to a 2.1mm, center positive, which seems to be the most common type.
- Added the ability to "disconnect" the PS/2 by removing two jumpers. This eliminates any problems with the PS/2 port being attached, but pins 26 and 27 used for other things.

Looking at futurlec's pricing for 15 boards with solder mask, each PCB should cost about $5.75, unpopulated. With all the components, minus propeller and eeprom, it should run about $10. Fully loaded with a Propeller, eeprom and all components, $25. Still less than a protoboard!

Post Edited (Philldapill) : 1/1/2009 12:13:09 AM GMT

Jim Fouch

Count me in for 4-5 bords.

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Jim Fouch

FOUCH SOFTWARE

Philldapill

Great! I'm now up to about 10 or 11 boards, so 4 more and I'll go ahead and place the order. After that, it should be about 10-14 days until they get here!

Oldbitcollector (Jeff)

I'd like one.

OBC

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New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

Whit

Put me down for two also! Are you sure you don't want to make a few more to sell as orders come in?

One last comment, you've got to get your name, ©, date and rev. # on there somewhere!

Philldapill Prop Board ©
2009 Rev. A

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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) : 1/1/2009 1:02:44 AM GMT

parts-man73

Oh, I don't know why I didn't see this before, you don't have any decoupling caps on the prop. If you plan to socket the Propeller, you can fit them under the propeller, that lets you get them really close to the power supply pins. I'd do one for each side. 0.1 uf or so. I've found that Machine pin 40 pin dip sockets give you the room, the cheap sockets put a reinforcement rib right across the center, blocking the area I normally put them. My point? look at the socket you plan to use before laying out the board, or you may find problems when you decide to solder them together.

I just got a design done that I put a USB connector to far away from the edge of the board. I had to dremel away part of the board to get the USB cable to plug in. My lesson learned, was to order the parts ahead of time and have them in your hand while designing. I had 4 of those boards made as prototypes. One of them sit on my desk now, unpopulated. I set my coffee cup on it.

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Brian

uController.com - home of SpinStudio - the modular Development system for the Propeller

PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!

SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board

Philldapill

Wow, great! Looks like I have enough people to get this thing going... However, a couple minor things:

To all of those that are interested that have not already expressed so, please Private Message me with your details such as Name, Address, Number of boards you'd like, whether you want just the board and regulator, the board with basic components(sockets, regulators, power jack, pins, resistors, but no PS/2 or RCA), or if you want everything on it except for the propeller and eeprom. I feel like I'm taking orders for pizzas...

To those of you that have expressed interest in a board or two, I'll PM you tomorrow and get your info. Right now, it's time to party like it's 1999.

Happy New Year!

jazzed

Nice board Phil. Brian's right about decoupling caps ... put down some 1208 or 806 smd device pads with short fat traces. There is nothing on the back so a ground plane would be nice there and will make the fab easier to spin. If it was my board I would allow a provision for putting smd resistors in series with all propeller traces. I like your form factor. It would be easy to mount boards in parallel. An smd prop version later might be a cool idea. Happy New Year.

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Philldapill

Thanks for the tip, jazzed/Brian. I've added one under the prop socket. I've used this same prototype without a bypass cap and never had any trouble, but a 1uF ceramic should make it even more rugged. Thanks guys. I'll post the final draft for production in a few minutes when I'm back home.

Philldapill

Wow, guys... I was only shooting for making 15 boards, but at last count, 23 have been requested. I guess I'll go ahead and get 30 made - should be a little cheaper.

Philldapill

One more tiny feature I'm thinking about adding - Mono Audio. I'm ordering all these parts from futurlec, and they have a dual RCA jack available for cheap. The pin footprint is smaller than the single RCA jacks I've looked at, so I think I can do away with the plug-in adapter idea and go with a mounted Dual RCA jack instead. Video will be on pins 20-23, and Mono Audio will be on pin 24. Like the PS/2 port, I'm going to try and add jumper pins so that you can disconnect any RCA circuitry to free up these pins.

Forrest

I've heard Futurlec has LONG lead times - weeks.

Ed Parsons

I'd have to support what Forrest says - although it was a limited experience. I ordered one of their DS1307 Real-Time Clock Mini Boards. After I hadn't heard anything for a week, I sent them an email and they said that they had run out and were waiting for more to be made. After another week and a half, I finally got it.

Ed

Chris Savage

Hello everyone…if the board designs are hashed out, the For Sale stuff should be posted in the Sandbox forum so we can stay on topic in this one. I’m just trying to keep this forum clean. A lot of OT posts have been moved from here lately. Take care.

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Chris Savage
Parallax Engineering

Philldapill

Sure thing, Chris. This thread started to became non-Propeller oriented on the last page. I think I've got my design pretty well worked out now. To be honest, this thread was started so the more experienced people, who have made their own propeller boards, could give some critiques and suggestions on the layout - NOT so I could start a new business. [noparse]:)[/noparse]

Thanks for all the replies, guys.