Single-Board Universal Module

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13 May 2014 09:17 #23182 by SeByDocKy
Replied by SeByDocKy on topic Single-Board Universal Module

Mmon77 wrote:

Around 40 USD, it's still very interesting ... coz actually with MM I am not sure that BOM is much lower than 40 USD when you add extra pins headers, extra uFL cables, wires ... it should be close to 35 USD. By the way, If I can order one of this single board, I will do ...


Yes, but to sell the assembled boards, you would also have to add the cost of assembly and FCC certification (at least for sale in the US). So that would change the price accordingly. Unless of course you have the means to assemble one yourself.

It is still an interesting proposition and hopefully it goes somewhere.


True ... the FCC certification can kill the certifation ... Can be produced in North Korea ? :)

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13 May 2014 13:47 - 13 May 2014 13:48 #23188 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
Just to get a feel for it, I priced out the BOM for:
1 part: ~$40
10 parts: ~$34
100 parts: $28
1000 parts: $23
There are parts I can't get from the same supplier, so those prices could shift around by about $5. Also, I used Digikey as the supplier because it was easy to price that way. They are certainly not the cheapest supplier.

Lastly for the bluetooth version (PWM/JR module) you'd need to add another $10 to the cost

I've been told FCC compliance would run ~$5000 (though I don't know how reliable that number is)

I'm guessing here, but you should assume that anyone who would want to sell these would charge ~2x the BOM cost to make any profit at all.
Last edit: 13 May 2014 13:48 by PhracturedBlue.

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13 May 2014 14:05 #23189 by IMback!
Replied by IMback! on topic Single-Board Universal Module
outch

considering the low amount of deviation users who need 4 modules and the price I can't see more than 100 being sold. witch would make the price about 130 USD. I can't see it being competitive with the old multi module.

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13 May 2014 16:00 #23193 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
Right. That is why the PWM capability is there. It provides the ability to use Deviation's protocols with any radio. We know there is an interest in the Anylink/Orange/Magic Cube, so I assume there is an interest in something that would do what all 3 of those do in one package.

Whether there is enough interest, I don't know. As I mentioned in my 1st post, this may never come to fruition.

As far as costs go, prices can vary wildly based on supplier. Once you get past ~10 units, the main costs come from the 7 primary chips (below 10 units you pay a huge premium on the passives)
These chips don't get huge price-breaks on the volume were talking about. For the 10 pieces kit from Digikey, I estimated these at about $22
When priced from China, the price appears closer to $10
There are other pieces that could additionally reduce costs. For instance the crystals in the board are around $4/board. From china those would be $1/board instead. Unfortunately for many passives, you take a risk in tolerances as you go cheap, which could result in the board not performing well. This is one of the reasons I need help from RF experts who have experience choosing appropriate parts to balance price and performance.

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13 May 2014 16:51 - 13 May 2014 17:00 #23197 by IMback!
Replied by IMback! on topic Single-Board Universal Module
A jr style module might be viable, but i would think it would defenetly have be below 100usd otherwise its a tough sell agenst just buying a devo10 and using deviation there. That said i love the idear and for ~80USD im defenetly in. over 80USD i would just buy a old multy module though.

Btw if the price is not impacted mutch headers for analog/ digital inputs would make it easy to retrofit old txes with deviation ex to retrofit a 2801pro or as an easyer way to increase flash on a devo7e. On the other hand that might make the board to big to fit into a jr module

Anyways dont mind me Im felling pesemistic :S
Last edit: 13 May 2014 17:00 by IMback!.

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15 May 2014 00:51 #23244 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
I did some work on placement. The outline here shows the size of a Devo module, which was my target size. It doesn't look like that will be possible though. I was able to squeeze all the components in, but I don't think the ground plane will be robust enough, and I don't think I have enough room to actually route the design (the bottom layer needs to be a ground plane under the RF portion to perform properly). I'm currently trying to figure out how big I can make the module and still fit it into all Devo radios.

I wasn't able to fit the headers onto the board, so those are likely to be casualties (only preserving the Bluetooth and Devo ports)

Attachment UniversalTxPCB.JPG not found



If I can add 5mm in width and 2 in height, I think everything will fit.
Attachments:

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15 May 2014 02:19 #23248 by victzh
Replied by victzh on topic Single-Board Universal Module
It looks like 5-8 hours of placement work!

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15 May 2014 02:41 #23249 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
Honestly, I'm not even considering doing it myself. My hands just aren't steady enough, and therse parts are really small. Ideally I'll team up with someone to get the boards produced. Worst-case, eventually I'll pay to have a set of prototypes run through an APCB shop.

I got my F072 discovery board in the mail today. I'll need to hack up one of my nrf modules and see if the interrupt is fast enough soon. Probably not this weekend though. Other stuff going on.

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15 May 2014 03:35 #23250 by victzh
Replied by victzh on topic Single-Board Universal Module
No, I mean how long did it take you to route all this? I don't see anyone except maybe enthusiasts (and I don't count myself as one) actually placing this amount of components, but you routed all of it!

Take a look at quotes at smart-prototyping.com, last time I checked they had an online quote system. I have no assembly experience, but my friend did PCBs with them. I don't remember whether seeedstudio.com have prototyping or not, but they may be interested in doing this anyway, may be on consignment basis.

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15 May 2014 04:17 - 15 May 2014 04:20 #23251 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
I haven't routed it yet except for half of the A7105 module (which I did just enough of to get an idea that it was feasible). And yes I expect it'll take me many hours to complete. As it turns out the RF portion is all based on the reference designs (except the CYRF module) so generally placement can be done on a single layer, which makes things a lot easier.

I want to finalize the board dimensions before I actually spend the effort to route it. Seeed does PCBA, but only using their stock parts which are larger than what I need. I got an online quote from smart-prototyping, which was ~$1400 to do 5 boards (or $1200 for 1) as I recall. I'll likely shop around more if it comes to that.
Last edit: 15 May 2014 04:20 by PhracturedBlue.

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15 May 2014 04:32 #23252 by victzh
Replied by victzh on topic Single-Board Universal Module
Wow! $1400 is a bit steep! I may consider placing it by hand. Unfortunately, it does not end there. Despite of reference design we probably need to adjust values of network to match 50Ohm - all this varies with surrounding parts and their relative position. And it you don't want to be blind, you need network analyzer for 2.4GHz - I don't have one.

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15 May 2014 14:06 - 15 May 2014 15:13 #23260 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
I think I was looking at another company actually.
I just recalculated with smart prototyping.com:
I ended up with a price of $55 for one board or $24 each for 5.
That is using their manual service, and the prices seem incredibly low to me. It'll definitely be worth contacting them through once I'm further along.
Last edit: 15 May 2014 15:13 by PhracturedBlue.

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15 May 2014 15:23 #23261 by djtrance
Replied by djtrance on topic Single-Board Universal Module
Hi PB, maybe you can design a better solution than the original tx, maybe you can use a mimo technology. (multi TX and multi RX on the same board). I don't know if the multi tx can be use it in this proyect, because I don't know if you can send the package in the exactly in same time with 2 PA. but if you can do that, the range will be more than only one.

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15 May 2014 18:41 #23265 by SeByDocKy
Replied by SeByDocKy on topic Single-Board Universal Module

djtrance wrote: Hi PB, maybe you can design a better solution than the original tx, maybe you can use a mimo technology. (multi TX and multi RX on the same board). I don't know if the multi tx can be use it in this proyect, because I don't know if you can send the package in the exactly in same time with 2 PA. but if you can do that, the range will be more than only one.


Let's start with a working single board .... It's already very challenging to have a working and efficient design. Reming that PB is doing that with his spare time ... and all deviationTX users are ad vitam grateful for that....

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15 May 2014 19:06 #23266 by djtrance
Replied by djtrance on topic Single-Board Universal Module
I know it :P , is only a idea. I'm still triying to fix my devo f7, because I'm triying to help to microuav to port deviation to this radio and I know how hard is this work

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18 May 2014 05:08 - 19 May 2014 03:56 #23311 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
I'm now at the hard part. I've got the RF fully routed (though it may need some tweaking/component adjustment) and just need to complete the digital section. Trying to squeeze the routing into the available space is proving difficult and I'm not having great success. I could go to a 4 layer board and solve the issue, but I don't think it should be necessary. I know there are some folks here who do layout, so maybe someone will take a crack at it. Otherwise I'll keep plodding along on it.

Here are the eagle files for the circuit as things are. The only placement critical stuff (not in the RF section) is the 1x5header on the left and the 2x5 header in the bottom middle. Anything else is fair game. Also, most pins on the STM32 can be rearranged/reordered to improve congestion. The power pins need to be able to handle 500mA, so wide metal will be needed out of the LD1117. the LD1117 should really remain on the top of the board if possible. Design is being done to OshPark rules, though I'm sticking to 8mil traces where possible (dru file is included).

Anyhow, I'm taking a break for a little while. Feel free to have at it if you have the inclination, time, and skill.

BTW, I am working with some folks who have RF design experience who can possibly bring this to market (and will likely end up doing their own layout of the board). However, I have no commitment that will come to pass, so doing the design myself is a hedge against that progress.

Edit: Removed old version. See below
Last edit: 19 May 2014 03:56 by PhracturedBlue.

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19 May 2014 03:59 - 19 May 2014 16:02 #23329 by PhracturedBlue
Replied by PhracturedBlue on topic Single-Board Universal Module
Well, I couldn't leave it at that. So here is the fully routed board:





There is still a lot of optimization to do (as well as the RF matching). I also need to re-verify the schematic since I moved everything around. Still, I'm glad I was able to get it all done in 2 layers.

Edit: See below for updated eagle files with the brd file
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Last edit: 19 May 2014 16:02 by PhracturedBlue.

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19 May 2014 05:33 - 19 May 2014 05:34 #23335 by blackmoon
Replied by blackmoon on topic Single-Board Universal Module
Impressive work as always. I really don't know how you do it, you surely are one of those persons (unlike me) that don't need much sleep. :D
Last edit: 19 May 2014 05:34 by blackmoon.

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19 May 2014 05:50 #23337 by victzh
Replied by victzh on topic Single-Board Universal Module
The zip file does not have a .brd, so I could not enjoy it in full. Otherwise, it's impressive routing work.

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19 May 2014 12:36 #23343 by SadSack
Replied by SadSack on topic Single-Board Universal Module
Excellent work PB. Looks like it could even fit in stock module box....


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