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I want your help on the following: I have implemented a design where I am using an Arduino Uno for master and three Arduino micro for slaves. The communication between them happens over bluetooth and I am using xbees. So the master sends data and base on this data only one slave responds while the others ignore the packet. Based on the answer, the master sends new and so on.

The design works fine but the cost is rather high since I want to continue with more production on this but right now the whole set costs around 120$.

Now that my design works with Arduino, I want to go into the next level and develop my own modules and chips. I do have experience with VHDL, Verilog and FPGAs but I do not know how this process can lead into fabrication and I could not find many relevant info on the web.

So I do have this plan and could you please correct me or suggest me something different if it is that wrong.

  1. I will write the code in VHDL. For the bluetooth, i can use one of the ips found on Opencores.com

  2. Test my design using FPGAs

  3. Maybe verify my code

  4. Get the netlist or something else and send it (where?) for fabrication.

Is that methodology correct or not?

I do not care with how long it should take, I just want to know if that procedure can lead into producing a chip that could replace each one of my Arduinos and xbees.

PS: would it be possible at first to write in VHDL the code for the master only (only the control logic) and test it using xbee for the bluetooth and proceed one step at a time?

EDIT:

Ok, I know that doing the above is inefficient. But, supposedly, that I want to create my own chip, is that the right procedure? - in terms of what is going on in the industry - do not comment on cost/time/whatever. Because I do have a gap in how these things work in industry.

Chetan Bhargava
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ghostrider
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    Why not just buy bare metal AVR micros and whatever other components you need, and build the device without buying Arduino products? I will bet anything that it is going to cost more to develop, validate, and produce your device with FPGAs than cheap little micros. – Matt Young Oct 02 '13 at 23:34
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    You should know that it does take a long time to get ASICs made, several months. You didn't mention cost, which is good, because it will cost you over a million US dollars. Verification is a good idea. Check this question - http://electronics.stackexchange.com/questions/7042/how-much-does-it-cost-to-have-a-custom-asic-made – Samuel Oct 02 '13 at 23:57
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    I think the process you described could work. However, I doubt that the result will be economical, unless you want to produce millions of your chip. – Laszlo Valko Oct 03 '13 at 08:54
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    You do know that the arduino is really a $3 microcontroller and a PCB and you're primarily paying for assembly, right? – Connor Wolf Oct 03 '13 at 09:22
  • @ConnorWolf hmm I haven't thought of that. Can i just buy my own microcontroller and program it from the same interface? Does the same applies with the Xbees? If yes, I think at first I can buy the separate modules, and then if my product goes commercial then I can try go into designing my own chip. – ghostrider Oct 03 '13 at 10:41
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    Yes you can.The XBee cost includes software stack and certification (FCC, ETSI). – Lior Bilia Oct 03 '13 at 11:00
  • You mean you want to implement the air interface of the BT as well as the PHY into an FPGA? Or you want to use a BT module connected to an FPGA and use the FPGA as a fast processor? – FarhadA Oct 04 '13 at 11:52
  • @FarhadA I am mentioned the FPGA as something that I can test my VHDL code on, before sending it for chip production, lets say. Out of curiosity, more or less. The question is if I want to create my own chip for that, should that be the way or not? – ghostrider Oct 04 '13 at 15:50
  • Well, both yes and no, you can work on your BT higher layers inside the FPGA, but you need to have an air interface which can't be done inside the FPGA. The best way to do this is to use a 2.4GHz board connected to your FPGA and then go from there. But that is a pretty big job for a hobbyist. – FarhadA Oct 05 '13 at 06:12

2 Answers2

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Why do you want to use an FPGA? The requirements you've mentioned above don't give any hint of anything with sufficient processing and parallelism demand to suit an FPGA. In fact, Bluetooth is a massive endeavour in it's own right, even in software, I wouldn't fancy trying to build a Bluetooth stack in VHDL, even as an educational exercise!

If you want a cheaper Arduino, redesign the PCB to use a cheaper, but compatible, device, leave off the bits you don't need, integrate any new bits you'd like. Even that is a lot of work (especially if you want to create a fully-validated product which you can CE-mark, get FCC approval for, etc.).

And the next step might be to use an even cheaper micro, with all the extra software effort that that entails.

But I wouldn't consider an FPGA for this job.

Martin Thompson
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    Yes, i see what you mean and I will do tht first. But, supposedly, that I want to create my own chip, is that the right procedure - in terms of what is going on in the industry - do not comment on cost/time/whatever. Because I do have a gap in how these things work in industry. – ghostrider Oct 04 '13 at 15:51
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So you've collapsed anywhere from 6 to 24 months of work by a small team of people into 4 bullet items. In that sense, you're approximately correct for a Digital IC. This doesn't map as nicely to an Analog IC, that's more complicated.

rfdave
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