This is a repost of my answer on Quora .
Whether its hardware or software or any product, spend lot of time and energy in customer development . Finding out what users want and think they will pay for is more critical than what we think will be cool for them.
Since HW involves lot of capital, you need to get the above part right.Once you have it, you would need to figure out the device/product environment conditions aka environment limitations, regulatory restrictions/guidelines/requirement whatever you call and very likely you will be changing the product spec or operating conditions to match the new reality.
Then come up with product design (look and feel), in layman terms, the product casing or how users should feel like when they see the product. Very likely because of the product casing/packaging, you will very likely revise your spec again..
Next, from the spec you came up with talking to users etc, figure out what it translated to technical components. Like how many HDMI ports , VGA, optical . USB ports etc, what network interfaces you support, what will be the capacity of hard drive and whether it should be SSD etc..
In case of Apple-TV for example, you might need to video encoding/decoding etc, you need good video decoder…check who sells video decoder chips (probably ARM or imagination tech) , also depending what addln functionality you need, you will also need main CPU processor, so figure out if its going to be ARM or MIPS or Intel Atom ..While you are figuring this, also check the embedded OS you want the device to be running and then check if the compatibility of OS with HW at device driver level…
Check all potential vendors for each component and many times they give you sample pricing (typically in volume of 10K pricing …some times they might give you pricing for 1K pieces as well )
Once you have selected vendors, figure out the power consumption and see if the power budget makes sense.Figure out if you want to your device to be running both in Africa and Siberia ..Accordingly revise your power budget and therefore you will change product spec and/or product casing etc..
Next implement the design spec using platforms from upverter etc and simulate the design. Next select the PCB vendor who can do the design and manufacturing for you…Board design/packaging might impact lot of factors starting from Design spec all the way to casing etc..So this is important..
Add all the pricing and get the BOM (bills of materials) ..Check if the BOM makes sense for the price range you are planning to sell..If your initial BOM at this stage is for example 25$ , triple that number because you are still missing pcb design and manf, board packaging , yield, lab bring up , compliance testing , QA and other NRE costs…Now check if you are still making money for the price that your customer is willing to pay …If you initially planned to sell for 50$, but your BOM is around 75$, you are loosing money and unless you have lot of money where you can afford losses initially to gain traction, you might have to change your spec again..Most likely you will remove some components and/or reduce some components..for example you might say I will only add 2 HDMI instead of 4, you might reduce processor speed from 1GhZ to 750MHz etc…
Now go back to your customer and convince him that what you are still delivering is lot of value to him and you are still solving their pain points and only removing the nice to have features…If they agree, proceed further..
While you are doing all this, start your embedded and SW development process in parallel using developer or emulator prototyping boards…Have this ready first so that you can do the demo to potential customers/investors on how the product will perform once HW is done …Show them once manufactured, its plug and play ..get their reactions/feedback..very likely you might change your spec totally or part of it…Once you do this 2-3 times and feeling confident, accelerate your PCB board design and manufacturing and get the prototype out…As a start up ,never go for manf without getting SW/Embedded part ready ..Its more like a lean start up development model for hardware..
If you are building a ASIC like Apple does for their Apple-TV , its different on lot of other aspects and I wont recommend it unless you can raise 10-20M$ easily and can hire 10-20 HW engg team …Of course not every product needs an ASIC or even an FPGA and don’t have to rely on leading manf technologies….
As as others have commented , you need to worry if you are infringing IP or if you are creating IP, make IP protection as part of your design thinking and strategy process..You can start with a provisional patent to buy you time and give you a opp to figure if you still want to go ahead after the feedback from SW demo/product demo..
BTW, try to use opensource technologies and customize it where you can…especially the design tools..Some tools are very expensive…Some vendors give their tools free for folks using their IC platform…Another good advice is try to limit vendors as much as you can, it will save you lot of headaches on lot of areas…
I might have left lot of other pieces, but this should give you a good idea of the process involved..If you need details or clarifications, feel free to ping me..