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Hello there.  I'm currently developing a very simple Arduino accessory but could use a little help.  In particular, I'm looking to see if there is even any interest in such a product.

There is no denying that the Arduino's use of shields is one of it's strong selling points.  It allows someone to spend less time on the electronics and their physical assembly and get right down to tying everything together with software.  I, however, am not in a position in which I can jump on the shield bandwagon.  My first, and currently only, Arduino clone is the RBBB, a solderless breadboard compatible clone.  It does not work with shields.  So I thought to myself as to how I could remedy this problem.  The solution is a PCB that adapts the shield profile to a solderless breadboard.  Such a prototyping tool could facilitate 3 things.

1. It allows a person with a breadboard-compatible, shield-incompatible Arduino clone to experiment with shields.
2. It allows a person who uses other microcontrollers like the Basic Stamp, PIC, or one of a hundred others to experiment with shields.
3. If, instead of soldering pins to the bottom for the breadboard and sockets to the top for the shield(s), you solder pins to the top for the breadboard and pins to the bottom for an Arduino, you can use the adapter to connect a shield-compatible Arduino to a large breadboard.


As you can see, I already have a PCB designed.  It was extremely easy.  I just took the files for the SparkFun ProtoShield, removed the prototyping area and all the electronic components, and trimmed down the PCB.

I've crunched the numbers.  The board measures 1.85x2.10 inches.  My normal supplier of PCBs, Gold Phoenix, will sell me 39 boards, with electrical testing and ROHS compliance for about $4.11 per board.  Buying enough sockets for all 39 boards comes out to $1.44 per kit, and 56 pins per board comes out to $2.21 per kit.  Each unassembled, unshipped and unpackaged kit would cost $7.76.  That feels a little high, especially considering the ProtoShield the adapter is based on is $15.

Parts per kit:
S7004-ND 6 position socket x2 ($0.31270 at 100)
S7006-ND 8 position socket x2 ($0.39410 at 100)
A26509-40-ND 40 pin break away header x1.4 ($1.57200 at 10)
Gold Phoenix fabricated board, 2 layer, 1.85x2.10 inch, electrical testing and ROHS compliance x1 ($4.11)

What I am trying to get at is this:
1. Is there even a demand for such an accessory?  If you do want such a device, would you buy my kit, make your own, or modify a prototype shield kit?
2. Do you have any suggestions to make the kit cheaper?  I was hoping to make it $5, add no more than $3 for my labor and such, and ask that the purchaser pay for shipping.

Before you ask, this is not my first rodeo.  For a time I was building ArduinoBoys and selling them to the chipmusic community.  I managed to sell 68 of them before I decided to call it quits.
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I like the idea as it solves a problem, however it introduces a new problem too IMHO. Shields are relative "BIG", sometimes as width as some breadboards, so this design could cover all the holes of the breadboard, or at least a substantial part. A better design needs to be able to connect to a breadboard, without covering it. So here my thoughts:

* Imagine a PCB in which you can plug a shield (you made that working allready). However the PCB does not plug into the breadboard but has header pins so I can connect it with standard female/male cables to a breadboard or to an Arduino or to some other thingy. That gives the freedom searched for I think. The cable can be some flatcable or so.
[in fact I used a screwshield - http://www.sparkfun.com/products/9729 - this way.

* The PCB should have 4 mounting holes so it can be used in permanent setting

* The PCB should have a LED to show that the +5V is applied to it.

* The PCB shield could have a separate power connector (solderpoints for a jack like the Arduino?)

Question
* Why are the GND's not connected in your design?

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I like the idea as it solves a problem, however it introduces a new problem too IMHO. Shields are relative "BIG", sometimes as width as some breadboards, so this design could cover all the holes of the breadboard, or at least a substantial part. A better design needs to be able to connect to a breadboard, without covering it. So here my thoughts:

* Imagine a PCB in which you can plug a shield (you made that working allready). However the PCB does not plug into the breadboard but has header pins so I can connect it with standard female/male cables to a breadboard or to an Arduino or to some other thingy. That gives the freedom searched for I think. The cable can be some flatcable or so.
[in fact I used a screwshield - http://www.sparkfun.com/products/9729 - this way.

* The PCB should have 4 mounting holes so it can be used in permanent setting

* The PCB should have a LED to show that the +5V is applied to it.



Its funny that this discussion should come up, and in fact that these very details would be in your suggestions, as, as soon as this weekend I was preparing to release just such a board.

It is called the CideKick Breadboard Shield Stack Extender or just CideKick for short.  The first small batch sold out locally before I could even post about them online.

The red jumper removes the pin 13 led circuit( the red led )

Power is noted on board by the green led

The breadboard rail is powered by two sets of 5v pins attaching the whole assembly securely to the stack.

Positive rail is 5v Negative rail is ground

The reset button is brought out to the CideKick for easy access for shields that don't supply one

The 20 pin inline female header is 13-0 digital pins and 0-5 analog pins from left to right

In the final picture the red wire is in the pin 13 digital, green is in pin 0 digital and yellow is in pin 5 analog.

The 6 pin center header(between the pin 13 led and power led)
are aref, 3.3v, gnd, reset, 5v, VIN

The odd shape ( the hook looking part in the upper right) is to accommodate the shield stack screw hole

Since I began with the Arduino there has sort of been a separation between my breadboard projects and projects that use shields, mainly because alot of shields don't supply the stackable headers or I dint want to always solder up a protoshield for each little change in a breadboard circuit, it completely defeated the purpose of the solderless breadboard Arduino combination many times.

You see this especially in some gps shields, some lcd shields and even things like the danger shield making it difficult to stack and run wires.

That is what drove my designs for the new Arduino Breadboard Tools, of which the CideKick is one, along with the WingThing, which addresses the very problem the OP posted about,  shield incompatibility with  insertables such as the boarduino and the ardweeeny, and the CINR which is a brand new format Arduino clone specifically for breadboard experimentation.

Sorry for the thread jack, but I figured this info was on point and relevant, as I said I will be releasing the full information on the Arduino Breadboard Tools this weekend, feel free to PM me for further info or any direct questions, in the mean time here is a  quick peek at the CideKick.


cidekick01

cidekick02

cidekick03

cidekick04

cidekick05
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Nice cidekick Boz,

it can connect shields to a BB without the Arduino underneath and without covering the BB.

Good idea to connect the GND rail to the GND pin of the shield, however, for the 5V I would prefer to keep them separated (or better, switchable) so I can have a separate power supply for the BB 5V line. The GND's connected is needed for signalling from shield to BB and back. Maybe the Cidekick 2.0 could have a power connector so it can supply the BB?

Furthermore I would prefer a one piece shield above the two pieces connected with flatcable because of stability.  Maybe add connectors (holes) on the back for RS32 & I2C & SPI pins?




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This is a one-piece shield:

http://arduino.cc/forum/index.php/topic,59582.0.html
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I like the idea as it solves a problem, however it introduces a new problem too IMHO. Shields are relative "BIG", sometimes as width as some breadboards, so this design could cover all the holes of the breadboard, or at least a substantial part. A better design needs to be able to connect to a breadboard, without covering it. So here my thoughts:

* Imagine a PCB in which you can plug a shield (you made that working allready). However the PCB does not plug into the breadboard but has header pins so I can connect it with standard female/male cables to a breadboard or to an Arduino or to some other thingy. That gives the freedom searched for I think. The cable can be some flatcable or so.
[in fact I used a screwshield - http://www.sparkfun.com/products/9729 - this way.

* The PCB should have 4 mounting holes so it can be used in permanent setting

* The PCB should have a LED to show that the +5V is applied to it.

* The PCB shield could have a separate power connector (solderpoints for a jack like the Arduino?)

Question
* Why are the GND's not connected in your design?



Thanks for the suggestions.  Two PCBs, one for the breadboard, the other for the shield(s), connected via ribbon cable.  Doable, but perhaps a bit more expensive.  I can see how an LED and a dedicated power supply could be useful, and I could include them in the layout, but I'm not so sure I would include those parts in the kit.  Maybe.  Oh, and the ground pins are connected.  It is called a ground plane.  All the excess copper on the board is connected to ground.

Let me get back to you on this.  I think I have a great idea.
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Good idea to connect the GND rail to the GND pin of the shield, however, for the 5V I would prefer to keep them separated (or better, switchable) so I can have a separate power supply for the BB 5V line. The GND's connected is needed for signalling from shield to BB and back. Maybe the Cidekick 2.0 could have a power connector so it can supply the BB?

Furthermore I would prefer a one piece shield above the two pieces connected with flatcable because of stability.  Maybe add connectors (holes) on the back for RS32 & I2C & SPI pins?


Actually switchable power on the rail was in several of the alphas but in testing and designing for the broader mass usage it was realized that a large group of people  just want use the standard  5v from the board to power experiments, so we went with that as the standard. Keep in mind that it is only the top rail that is powered, you can still place an external supply on the second or bottom rail.

In addition you can also have the CideKick supply 3.3v, 5v or even VIN to the second rail or anywhere else on the breadboard for that matter.

Also as I said the CideKick is just one part of the Arduino BreadBoard Tools, the CINR (sounds like sinner) has switchable power on the rails and you can chose from internal or external, 3.3, 5v or VIN to be put either or both of the rail sets or different on each rail.

As to the the flat cable versus solid board, again in an early beta the CideKick (sounds like sidekick) was a solid board, but was switched to the cable to allow direct access to the ICSP  header so that a programmer could be attached without having to the take the stack apart (see cidekick02 picture above for the header in stack access view) if it was a solid board you likely would have to seprate the stack as the ICSP is also not commonly passed through all shields. Access to the rs32 header location was also maintained.

In addition with the 16 pin header inserted the outer end is just as stable as if it were a solid board, there is no play in the stack and on one last note on that by making it a cable instead of a solid the Arduino's screw mounts, 3 in the dumilanove and 4 in the uno, were left accessible so stack stability can be maintained with less mounting hardware than if it was a solid board.
 

Great piece liudr, looks like we were on many of the same goals in our designs in similar time frames, in fact in my case the Arduino Breadboard Tools came from a project that started with a harddrive cable setup also.

You can see it here http://www.musheen.com/arduino-solderless-breadboard-prototype-station-568.html from January 2010

It is a good solution for many, but I wanted to overcome the typical problem with cable insertion solutions like yours and insertables like the boarduino and the ardweeny, which is the loss of Breadboard pin space and a large chunk of breadboard real estate even when not using all the pins. The CideKick brings all the pins close to the center of the work with out wasting pinspace on insertion.

The CideKick also shares alot of the features of your project, while your focus was connectability , my focus was compactness, maintaining access to programming headers and stack mounting hardware, visual cues for power and and pin 13 and easy access to the reset button outside the shield stack.

As the old saying goes "there are many ways to skin a cat" and both projects show strengths and take different paths in doing a similar thing, bridging the gap between breadboard and shield experimentation, so cheers.

Oh and robtillaart here is a teaser shot of one of the other Arduino Breadboard Tools, The CINR, with part of the switchable power supply visible and the ftdi out.
   

cinr_teaser00
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@liudr,
That looks quite like my mental image! smiley has it mounting holes ?.

@Boz,
Rail-connection: good motivation for your choice

One shield: Good point, about keeping the ICSP header free, but that is only needed if there is an Arduino in the experiment.
If I want to use an Arduino shield with another processor (e.g. residing on the BB) that has not the famous pin layout I would prefer Liudr's shield

That said, you really had a good though about your design, I appreciate you sharing these arguments as it explains the product as it is. Well done and thank you.

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@liudr,
That looks quite like my mental image! smiley has it mounting holes ?.

The shield side has no mounting holes as those holes will be covered by shields stacked above it. The breadboard connector side has two mounting holes. You can use this side to distribute your wires in a project and just mount this board inside the project. If you need the arduino, disconnect the cable and take it away with the shield. If you come back to a project, insert cable to the breadboard connector and your project is back alive.
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Just FYI, my shield is not selling like hot cakes (a couple dozen sold but I made 100) so for those that want to sell your similar designs, test the water with a smaller batch. That's what I'm gonna do for any future project.
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Please note that it is not done.  There are still some labels to place and I'm starting to warm up to robtillaart's idea of adding a 5V supply.



The inside of the board is supposed to be cut out with a coping saw to form the breadboard adapter.  It would be wasted PCB material otherwise.  The two boards are then connected by a 26 conductor ribbon cable.

The holes are supposed to line up with the holes on a shield, just in case someone wanted to use the adapter in a more permanent setting.  The kit would also include four adhesive rubber feet to stick to the bottom of the shield adapter board.

Thoughts?  Concerns?  Complements?  Complaints?
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Just FYI, my shield is not selling like hot cakes (a couple dozen sold but I made 100) so for those that want to sell your similar designs, test the water with a smaller batch. That's what I'm gonna do for any future project.

Yeah niche product sales are a funny thing sometimes its just right moment right place, sometimes its the right tweak to make something look, feel or work better and more intuitive, and sometimes its just a damn unknown whim why something clicks.

Like I said my first small batch of 25 CideKicks sold in a week and a half in the real world to friends and friends of friends, didn't even have enough time to get them online, does that mean a larger run will sell just as fast nope, but I do know I have a number of people interested in getting more and a distributor has given me an intent to purchase quantity so like I said each piece sales depends on way too many variables to make generalizations, either good or bad about what something might do based on what something tangentially related did before, you roll the dice, you do your best and you see what comes of it.

Good luck on your sales, maybe more exposure in threads like this will help.
 
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I don't have as many friends. Anyway, nice to see many designs for similar purpose. I tried to find distributors but was not very successful.
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