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UPDATE June 21, 2012:

I purchased a Ferric Chloride, Positive Developer, and positive PCB boards from MG Chemicals and used the photo-etching process. The results were OUTSTANDING! You don't need their sparge tank or exposure kit. I simply exposed my pcb underneath a 20W compact florescent bulb for 10 minutes, developed the pcb in a tupperware dish according to the instructions, and then etched in the same (rinsed out) tupperware dish for 15 minutes while agitating occaisionally with a foam brush.

Also, I used an inkjet printer. The instructions say only to use a laser printer, but I found that if I set my printer to print the transparency using very dark, rich dpi settings that I had sufficient contrast.

The results were great--super fine and detailed thin traces!!

Background

I recently purchased some Syma brand indoor RC helicopters for my nephews. Well, I had so much fun enjoying these with the boys that I have since started a small collection of my own.

Although loads of fun and durable, these toys use cheap electronics:

  • An infrared transmitter/receiver that seems to lose signal quality in a brightly lit room
  • Single channel so that you and someone else can't fly at the same time without interfering with one another.

About me:

  • Not an electronic engineer, though I am technically minded.
  • I am very much a novice with soldering and wouldn't be capable of soldering the tiny board inside these little birds.

What I would like to do:

In an ideal world, I would like to have a custom circuit board made for these little birds that

  1. Accepts a non-infrared signal (2.4 GHz? Bluetooth? Wi-Fi? --Remember these are "living room" flyers).
  2. Allows for you to choose between 2-3 channels on both the transmitter and receiver so that 2-3 people can fly concurrently.

I realize that this might already be available for bigger outdoor birds, but I need the circuit board to be small.

Is there a cost-effective way of prototyping this? Is there perhaps a place where I can send them the specifications and they would "print" up the circuit? Software that a semi-layman like myself could use to design it? I realize that the first run would be expensive, but I can see this being an after-market item that those of us bitten by the indoor heli-bug would buy enough of to bring the cost down.

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  • \$\begingroup\$ I don't want to crush your hopes, but I must say that for you as a beginner, it would be extremely difficult to make a circuit board that could drive a helicopter of that size. I don't think that they could even lift just the bluetooth board from the accepted answer. So for your first boards, I would recommend that you move up a bit on the size scale for your first boards. Larger helis will require a bit more complex electronics (if you decide to include gyros), but you won't have to worry as much about the size and mass of the PCB itself \$\endgroup\$ – AndrejaKo Mar 30 '12 at 18:49
  • \$\begingroup\$ Take a look at diydrones.com a website for hobbyists making their own UAVs including electronics. \$\endgroup\$ – JonnyBoats Mar 30 '12 at 20:48
  • \$\begingroup\$ Its not that bad, recently hackaday featured a zigbee controlled heli based on an atmega with a built in 802.11.14 radio. \$\endgroup\$ – joeforker Mar 31 '12 at 5:07
  • \$\begingroup\$ @AndrejaKo-Thanks for your advice, I agree. I think what I am going to do is just solicit help from the open community on this one. I know that there are other enthusiasts out there (like on diydrones.com) and some of them might be Electrical Engineers. My interests also extend into things such as better, more accurate body types for the heli and so forth so I will have to hope that this can be a team effort or else I will never be able to do it all. Thanks so much for your time! \$\endgroup\$ – Matt Cashatt Mar 31 '12 at 11:59
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For cost effective, full feature software, nothing beats open source software. I use the gEDA suite of tools for my electronics designs (schematics and PCB layout) but there is also the KiCad suite which might be a bit easier to use. There are several others as well. Try playing with them and doing some layout tutorials to get to know the software.

For PCBs, you could try places like Fusion PCB or DorkbotPDX. I have also heard the previously mentioned Batch PCB is good too.

For wireless, you could use something like this bluetooth to serial converter from DealExtreme. With bluetooth, you can pair devices and then it doesn't really matter how many birds you have flying around. You could also develop a smartphone app to control your helecopters.

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  • \$\begingroup\$ Thanks ben. This answer was perfect, direct, and gave me options for what I am trying to do rather than reasons why I probably shouldn't. I am amazed at how inexpensive batchpcb.com is! \$\endgroup\$ – Matt Cashatt Mar 30 '12 at 16:17
  • \$\begingroup\$ Thanks for picking my answer! When looking at the PCB fabricator, don't forget to look at the services they provide. I believe BatchPCB's cost gives you just a single copy of your board while Dorkbot gives you 3 and Fusion gives you 10+. Also, Batch does not test the PCBs while Fusion does (I'm not sure about Dorkbot). \$\endgroup\$ – ben Mar 30 '12 at 16:22
  • \$\begingroup\$ It's a common mistake to think that open source and free are the same thing. Open source is often free, but there's no law against commercial open software. \$\endgroup\$ – stevenvh Mar 31 '12 at 15:41
  • \$\begingroup\$ Does anybody know of any cheap custom PCB companies operating in the UK? It's ludicrously expensive to ship from the US :( \$\endgroup\$ – Polynomial Apr 1 '12 at 12:43
  • \$\begingroup\$ @stevenvh: True. I did say "cost effective" though, plus the software I linked actually is 0 cost. Also, there is free as in freedom, and free as in cost, but I will not rant about that here :) \$\endgroup\$ – ben Apr 2 '12 at 14:21
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So from your post you need complete design services for a small run of custom electronics involving radio communications to a mobile platform. Since you're not an EE this is not something that you can do yourself. You can't piece together something from multiple sources that will work without in-depth technical knowledge - you need someone to design this for you. Electronics are not Legos - they're not designed to work together seamlessly. That means you need to pay someone or get them to do it for free.

The level of effort (billable hours) on this is probably something on the order of:

  • 4 hours to sit down with you and hash out all of the requirements
  • 8 hours to do parts selection
  • 40 hours to do any coding (if necessary)
  • 40 hours of schematic capture and layout for the board
  • 16 hours to test
  • 40 hours for rework and the next revision (if necessary)
  • Much much more effort for any certifications necessary to make it into a real product

Real engineers are paid on a contract basis generally $100/hour or more. If you want this to be a real product you need someone who has been through that process before - more expensive. This is quite an effort to contract out. If you do find someone they will handle the board manufacture but you'll have to pay for parts and boards. Boards also take up to weeks to get and you'll be looking at one or two revisions. This will take months and it will be expensive.

As for where to find someone to fit these criteria... dunno. DOes anyone know of a website where people can post small contracts like this? I think it would be a good resource.

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  • \$\begingroup\$ Thanks AngryEE, it's nice to know about what to budget for actual consulting help. \$\endgroup\$ – Matt Cashatt Mar 30 '12 at 16:16
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    \$\begingroup\$ Ponoko (ponoko.com/ponoko-id/id-overview) has a place where you can ask for help on projects (though not specifically EE projects). SeeedStudios Wish might also work. (seeedstudio.com/wish/?page_id=12) \$\endgroup\$ – ben Mar 30 '12 at 16:17
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PCBs are first designed with a schematic. You can find a large amount of options for schematic editors for the question Good tools for drawing schematics.

Once you get the schematic drawn you will need to "transfer" the schematic to a layout program. This is really only ever done with in a single program. For example, eagle is a pretty commonly used program. You create a schematic, and then within eagle you transfer it to a pcb. From this point you will need to place all of the parts in your layout.

Once the layout is complete, you can export the layout. A typical format for this is gerber files. You then send those files off to a PCB house who will then fab the board for you. There aren't many cheap options for soldering boards for you in small quantities just because of the large amount of setup time required. One option though is batchpcb.com

With all of that said, I think you are taking on a project that might be a little much for you right now. Brainstorming questions are best for the chat room, so I wont go into much detail here. Here are my concerns for you... It is an art to get PCBs very small and you will need pretty small pcbs in order to get them to fit on those small helicopters. Also, people tend to like to make their first PCB in every project a little bigger so that you have room to change things or adding prototyping pins, etc. You would probably be best to buy yourself a development board of some sort, possibly an Arduino with some RF shields. This will allow you to do some prototyping in an environment that is very easy to do things in. This will help to get you up to speed with what all is needed to make something like this. You could then take the step of turning it into a PCB that can fit on to the helicopter.

Also, you shouldn't be scared of soldering. In small quantities, you will be able to save money by buying yourself some soldering equipment instead of paying someone else to do it for you.

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Last I checked, the most cost-effective place to get small-run PCBS is http://batchpcb.com/ by the people behind SparkFun. However, you will be waiting a while (for me it was about a month from upload to delivery.)

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Unless you're really set on doing this yourself, you'd be a lot better off taking a look at radio control from companies that specialize in it:

  1. Futaba
  2. Airtronic
  3. Hitec
  4. JR

You can get those (and probably at least a few others) from dealers like Tower Hobbies, RC Planet, Hobby People, etc.

Even using a pre-built transmitter and receiver, you'll get an opportunity to do a bit of engineering, getting the receiver to talk to the existing servos (or replacing them with those supplied with the radio) along with (usually) some mechanical engineering getting things like the throw on the servos correct.

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