Hi
I have just demonstrated a data capture and send device based on the arduino and gsm terminal. The client now wants to move onto pilot phase and if successful full rollout .. up to 4000 units.
I am thinking of using a Pro Mini for this. A custom PC board will have to be made for housing the GSM Module and Mini as well as some I2C I/O expanders ..
Does anyone here have experience with something like this? Perhaps the Arduino team can provide some guidance?
No experience on something like this, but I have to ask if your client is aware of your limitations? Perhaps they can help guide you if they are? If I were your client, and weren't aware of your limitations up front on a project this large before I signed the contract, I wouldn't be very happy. I would also further be unhappy that you hadn't planned on this occurring prior to this phase in the project...
Good luck.
I think you misunderstand. I am the idea / prototype / software guy, the project will be outsourced where required.
What's the point of planning the whole project to conclusion before doing a prototype demonstration? :-?
What's the point of planning the whole project to conclusion before doing a prototype demonstration?
Ideally, it would be a successful project - that's what planning is for.
The way you were talking, though, you made no mention of outsourcing everything; you seem to have no experience with a large scale project of this sort (neither do I, of course) - it just seemed like you were doing "everything"...
So - if you are only the prototype developer, and everything else will be outsourced (by the client?) - what do you care what happens after the prototype is developed?
Now that I look at your initial post; maybe the format of the sentence structure is throwing me - are you instead actually asking how to integrate a pro mini, a custom PC board, a GSM module, and I2C expanders into a case or something?
I thought you were the prototype developer (who should have experience on this)?
:-?
Ahh ..
Well to clarify the hardware device is only a smallish part of a bigger picture.
I work like this .. client has a problem, I propose a solution and demonstrate a prototype with cost estimation. If the client is happy with the proposal I source whatever is needed and provide the rest. The client is not concerned with the details. (This applies to all my projects, electronics included or not)
The reason why arduino features here is because at the volumes indicated I don't think its worthwhile designing a whole new Atmel based board AND the programming side of the arduino suits me. It also breaks down to a modular approach which I prefer.
Of course I could have gone the another route e.g. outsource even the prototype to 'professionals' but that route often proves to be expensive and slow ... and .. I'd rather support the open source community.
If I were going to do something like this, I would probably approach it in the following manner:
Draw a schematic for the prototype. Include all parts; design using the ATMega in "bare bones" configuration; include programming header for FTDI cable.
Build the prototype from the schematic - use stripboard or something; ATMega328 bare-bones with bootloader, put on programming headers and use FTDI cable to program it (or include the mini - though a mini seems like overkill, but for a prototype, who cares). You would probably need breakout boards for the I2C expanders and GSM stuff to get it to fit. Write the code, get the thing working, perhaps stuff it in a box (I am not sure where you are at on this point).
Once the stripboard prototype is verified and working (and, if you went with the mini - you might want to try the bare bones version next - prototype 2), design the PCB. You seem to not have experience with this - so it might have to be something you would outsource; give the designer the revised schematic and such (they might even need a prototype to verify things).
Once you get the PCB design made, have one or two etched and drilled by a PCB maker (several available worldwide - actually, I ran across one somewhere in SA just yesterday - seemed like a small outfit). Bring it home, stuff it with parts to verify the design is working; if not, check for problems, check the PCB design, check the prototype, etc - repeat steps 1-4 until it works.
At this point, you should have a working PCB layout, and a parts list. Find a combo board maker/stuffer - or have the boards made at one place, and stuffed elsewhere. Do a small run first, of say 10 boards. If those come back working and test out fine, then it just a matter of ramping up the production with the manufacturers you are working with.
Once you have a working and final sized board (although you may want to work with the PCB layout designer on this first), find a manufacturer for the cases to fit; sometimes it is easier to pick a case or a manufacturer, and get the sizes needed for your board designer, then design the board around the case dimensions. Otherwise, a custom made case would be needed (necessitating costly tooling and such - not a cheap thing to have done).
Once again, though - I have no experience in any of this, so take it with a grain of salt and do more research; the above is just what I would do based on my minimal research into how you go from a design to a prototype to a product - there are still many gaps in there, but I think the major basics are covered, but once again I have never actually done this. But the resources are there.
Good luck.
Gotcha. Note that the prototype is fully operable already.
Schematics can only be finalised however if I can confirm supply on the arduino modules.
This part seems to be proving more difficult than I expected ..
the point is that for 4000 units, you shouldn't be using an arduino module any more. You should be using the equivalent circuit based on a bare AVR cpu and associated components (there aren't very many...)
I work like this .. client has a problem, I propose a solution and demonstrate a prototype with cost estimation.
So you've already given a cost estimate without a manufacturing plan?
What do you need the i2c expanders for? you know they don't come cheap.
Something of note: right now, it seems you can only source ATMegas out of China (though I have only checked thru-hole DIPs) - here in the USA, for example, Digikey and Mouser won't have any DIP ATMegas available until sometime in April or May (if I am reading their backorder stuff correctly) - but if you go on Ebay, you can find everyone and his brother selling them out of China (also check ic2ic.com - same thing; tons in China).
I would seriously consider going with an embedded ATMega instead of a full Arduino - you are likely going to have the boards etched, stuffed, and shipped from China anyhow (from a cost standpoint), so an ATMega with programming headers (to use an FTDI cable, for instance - you may also want to include pads or headers for an ISP programmer, too - in case a new bootloader is needed). It will probably be easier sourcing a big supply of ATMegas (well, at least from China) than a big supply of the Arduinos.
Thanks cr0sh I've never bothered to check eBay for AT's before.
These 328 standalones with bootloader, resonator, 7805 and socket are pretty cheap, US7 per unit and free shipping.
Just bought some from Avnet, in stock 328p in DIP for $3.09 or so.