I'm an Electrical Engineer/Entrepreneur who has done hardware design for small startups.

It sounds like with a working Arduino prototype, you are well on your way.

How is your idea/prototype being received? Are people interested and have you been able to get market research/feedback on what people would be willing to pay?

Redoing the circuit design for a non-Arduino second prototype and doing the mechanical casing/enclosure is not a trivial task, but doesn't have to be exceptionally costly or time consuming, either. Depending on what circuit you are designing and what sort of molded casing you need, you could have a self-designed prototype in a few weeks to a few months for perhaps as little as a few thousand dollars.

The real key in a hardware design is making sure that it is designed for easy manufacturability and low cost when you are ready to build in quantity.

You'll probably want to do you initial runs using a local or regional contract manufacturer, but down the line you may want to do mass production in China, etc. Setting up this pipeline and doing quality control with this is often the most difficult part of the hardware process (just ask the Wakemate guys), but can definitely lower the cost. You have to balance the numbers, though. If the quantities aren't there, I've found it best to fabricate locally.

Regardless, feel free to drop me a line if you are interested in talking more about the process, timelines, and costs involved.

I may be able to help you out with the circuit and meechanical design, as well, if you are interested.

>where one would even begin if I wanted to take my weekend Arduino project, and turn it into a commercial gadget

I have no actual experience of this, but ... Personally I'd do some research with the patent literature and see if you can find a patent that covers your device. Espacenet is the easiest of the patent dbs to search IMO, use ECLA/IPC key if you can. If you can't find it then consider patenting it.

Once you have spent time establishing the patent situation you can move on.

If you have patent protection then look and see what you can find close to the product that has actually been sold, if nothing then find a few companies that manufacture devices that are as similar as possible and hit them up letting them know you've got a patent (or pat pending) and take it from there.

Or, are you thinking you want to design circuitry, get necessary certifications, build out cases and advertise and market (b2b or b2c) for yourself?

>"it's a great idea"

Great ideas don't necessarily make great products. But don't let that get in your way, have fun!

Hey, I am an authorised Arduino reseller and have also been toying with the idea of a marketplace for Arduino projects. I'm based in London too. Drop me an email (in profile) if you are up for a chat.

The two hardware startups on here that I can think of are the WakeMate people and the InPulse watch team. Hit them up, I imagine they'll have some thoughts for you.

Great - thanks!