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P2D2 with P2-revB - taking orders! - Page 7 — Parallax Forums

P2D2 with P2-revB - taking orders!

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  • Good to hear then guys. I'd rather sacrifice a few units which can always be used internally anyway so that everyone has the latest and greatest and best. I have moved the rtc components onto the top already and I will send off this artwork today, after a few more design rule checks (not like last time). I may even get the HyperRAM board done today as well although perhaps I will concentrate on the dev board since it is a simple enough board but needs to have all the connectors in place etc.


  • Good to hear then guys. I'd rather sacrifice a few units which can always be used internally anyway so that everyone has the latest and greatest and best. I have moved the rtc components onto the top already and I will send off this artwork today, after a few more design rule checks (not like last time). I may even get the HyperRAM board done today as well although perhaps I will concentrate on the dev board since it is a simple enough board but needs to have all the connectors in place etc.

    yes, I will use my P2a's also for internal tests and projects.

    As said before I like to have 3 P2D2's but am NOT in a hurry, so will wait until everything calms down a bit...

    good work,

    Mike

  • I may even get the HyperRAM board done today as well although perhaps I will concentrate on the dev board since it is a simple enough board but needs to have all the connectors in place etc.

    What voltage are you planning to run your possible HyperRAM sandwich board at Peter? Is it from the nearby VIO (3.6V supply)? Is is a full size board or just a slim add on down one side?
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2019-11-29 16:08
    I'm ordering these pcbs and I'm thinking of using either a black or a red mask. Any preferences?

    edit: seems black is slightly conductive which may be an issue with ADC scope operation perhaps. There is a higher cost for red and longer turn-around, but green is much cheaper and faster turn-around.

    rogloh wrote: »
    What voltage are you planning to run your possible HyperRAM sandwich board at Peter? Is it from the nearby VIO (3.6V supply)? Is is a full size board or just a slim add on down one side?

    This board only needs to be big enough to span the smd I/O pads along the edge and even though HR can run at 3.6V I will just have a small LDO of the same type as the P2D2 on-board. That's the whole idea of pre-regulation.

    847 x 1384 - 390K
    416 x 329 - 93K
    416 x 330 - 95K
    415 x 330 - 96K
    416 x 326 - 97K
  • ErNaErNa Posts: 1,738
    green seems to be color of future. I personally would prefer european blue.
  • kwinnkwinn Posts: 8,697
    I find the green pcb's easier on the eyes while still providing enough contrast to make following traces easy.
  • I like the red but not if it is going to cost more and add to the delivery time.
  • Sorry, I've been around the last few days.
    Ok to wait here.
    No color preference.
    Still waiting for a european delivery quotation, to know how much to paypal.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2019-11-29 22:25
    Ok, I'm always thinking about how these modules would look in different colors when they are being advertised for sale but otherwise green is best an the least fussing. I have used red on pcbs before and it is very striking but adds 2 days to the pcb fab as it is. So i decided not to add any extra delay in getting them back and have defaulted to green and also fixed the panel size and qty otherwise I would have been ordered 400 pcbs!
    Fab build time on 30 2x2 panels is about 3 days. If I need a fancier design with all kinds of ultra-precise clocks etc then I will order this as a revision in small qtys for testing.

    @dMajo - don't worry, your order will still be processed as if you have paid and I will look at the most effective way of handling shipments to Europe.
  • Aussie green and gold! How could it be anything else? :lol:
    This board only needs to be big enough to span the smd I/O pads along the edge and even though HR can run at 3.6V I will just have a small LDO of the same type as the P2D2 on-board...

    Sounds good, the smaller (and thinner!) the better. I think I may just have room if I use some of those low profile pin header sockets.
  • rjo__rjo__ Posts: 2,114
    edited 2019-11-30 18:12
    I'm planning to order. Can you order and manufacture the PCB's so that you get a sheet of four? 2X2?
  • rjo__ wrote: »
    I'm planning to order. Can you order and manufacture the PCB's so that you get a sheet of four? 2X2?

    I believe that is what he is getting.
    Fab build time on 30 2x2 panels is about 3 days. If I need a fancier design with all kinds of ultra-precise clocks etc then I will order this as a revision in small qtys for testing.

    As to whether they are routed, I don't know.
  • rjo__rjo__ Posts: 2,114
    Best news so far. I don't know how I missed it.

    For the time being I'm planning to use it as a compute module and do a lot of bit banging. So I can do the routing myself.
    In the future I think there will be a place in the world for specialized clocking. When he makes it. I will buy it.

    What a weekend. Good Golly.
  • @"Peter Jakacki" I'm certainly happy to wait for as long as it takes for the standardised P2D2 design to stabalise.
    I have plenty of projects currently in play, so there's no great rush for me to start on my P2 exploration journey. :smile:
    I sent you a DM reply on 19-Nov to clarify some paypal payment details. So I'll just stand-by while you finalise your P2D2 "release" revisions.
  • Thanks again everyone for your support. The pcbs are in production with JLCPCB with a 3-4 day build time plus shipping so I will have them back during the week. They are on a 2x2 frameless panel with vgroove I believe which normally will snap apart cleanly but the 2x2 is a convenient size for hand stenciling and assembly.

    Of course there will be some :) who can use a 2x2 panel as is although a lot of space is wasted with pin headers. If you really wanted multiple P2s in a compact form you would use the castellated version that cuts the 100mil headers off altogether half way along through the 50mil headers, thus forming exposed pads suitable for SMD mounting. Or else you could leave the 50mil header intact and use 50mil header strips which is also something I will like to try myself.

    As for anyone who has paid extra and is happy to "donate" then that helps balance any shortfall on paper from various fees from other orders so that everyone is covered and no one has to worry about paying minor extras. Everybody relax.

    Although this is a not-for-profit venture, my overall aim though is to make it sustainable, even with wastage due to excess components and failures and write-offs etc. The yield always improves once minor hiccups are ironed out and testing procedures improved etc. If I were to do larger runs I would pass this all along to an assembly house, perhaps even via JLCPCB, but I am wary to do this in the early stages until I know what is involved in assembly and what needs to be improved, by assembling them myself.


    Build details
    Gerber file: CAM for P2D2R4_Y6
    Build Time: 3-4 days
    Layers: 2
    Dimension: 55mm*43mm
    PCB Qty: 30
    PCB Thickness: 1.6
    Impedance: no
    PCB Color: Green
    Surface Finish: ENIG-RoHS
    Copper Weight: 1
    Gold Fingers: No
    Material Details: FR4-Standard Tg 130-140C
    Panel By JLCPCB: X:2*Y:2
    Edge Rails: No
    Panel size:【X: 86mm Y: 110mm 】
    Flying Probe Test:Fully Test
    Castellated Holes:no
  • Yes @"Peter Jakacki",

    you are doing it right, no rush, test out, send out, iron out. repeat. (do I got the reverse order right for a forth minded reader?)

    In my opinion (not humble) the P2D2 is a very nice piece of art. I especially like the thinking you have with cutting them down as needed for castellated SMD mount. One can test with headers and the finally product can shrink down. Love It!

    Same goes for your addition of that second micro (forgot what its named) I hope that Parallax would adapt to that choice, for me it does make perfectly sense to integrate it in every design. Classical no brainer for that cost. And gives a lot.

    You are putting a lot of work and knowledge into this and I really appreciate that, but I might buy single digits per year so - hmm - not the big customer.

    Anyways I want to thank you for doing this and give you some feedback,

    Mike
  • HEADER SOCKET


    As many of you know the P2D2 has dual 2x20 100mill headers that can be cut off or have a header installed. The cheap and nasty way of installing a header would be to use pins, they are cheap and easy to get. But pins stick out and get bent and still need a suitable socket to plug into which makes it more difficult for a user whereas if all they needed to worry about were pins, then that would be easy. So I favor a female header on the module and that also makes the module more robust too and all you need are header pins to plug into. Also you can use the module standalone and plug resistors and capacitors and wires directly into the female header, a bit like a plugin breadboard.

    But female headers are typically 8 to 8.5mm high which means that with the 2.5mm pin spacer that means the module sits up to 11mm off the board. But I also use 5mm high low-profile or short female headers although I don't have any 2x20 in stock and make them up out of hacked non-stackable 2x8 and 2x4 headers. Messy. I can order the 2x20 short female headers at a good price from 4UCON but I need to order an MOQ of 1,000 and that takes at least 6 weeks. In the meantime I can also order some from a supplier as "short RPi female headers" in packs of 2 but they cost quite a bit more although I have asked for a quote. This is one of my dilemmas that I am in the process of addressing.

    Headers are helpful too for testing otherwise I would need an array of pogo pins to press onto to test all the pins. A standard header is important too and makes it easier to mix'n'match.

    So what do you think about the type of header? Socket or pin or none. Standard or short?


    937 x 610 - 760K
  • jmgjmg Posts: 15,140
    edited 2019-12-03 03:18
    ..
    So what do you think about the type of header? Socket or pin or none. Standard or short?
    That's the sort of thing best fitted by the user ?
    The RaspPi displays all seem to have sockets, so they expect header pins...
    Someone wanting to slave P2 to a PI, will need a socket....

    Someone else wanting to plug P2 into a lash-up, may want pin headers on PCB and disposable socket with flying wires, and selective pins removed...

    That said, sockets are not easy to source.
    I see these are ~ 9c/100+, is that low enough cost to 'include in the bag' ?
    https://lcsc.com/product-detail/Pin-Header-Female-Header_BOOMELE-Boom-Precision-Elec-C50982_C50982.html

  • jmg wrote: »
    That said, sockets are not easy to source.
    I see these are ~ 9c/100+, is that low enough cost to 'include in the bag' ?
    https://lcsc.com/product-detail/Pin-Header-Female-Header_BOOMELE-Boom-Precision-Elec-C50982_C50982.html

    I saw those ones earlier and I can't believe how cheap they are. I am really tempted to get them anyway even though they are standard height. Pins I have plenty of.

  • HEADER SOCKET


    As many of you know the P2D2 has dual 2x20 100mill headers that can be cut off or have a header installed. The cheap and nasty way of installing a header would be to use pins, they are cheap and easy to get. But pins stick out and get bent and still need a suitable socket to plug into which makes it more difficult for a user whereas if all they needed to worry about were pins, then that would be easy. So I favor a female header on the module and that also makes the module more robust too and all you need are header pins to plug into. Also you can use the module standalone and plug resistors and capacitors and wires directly into the female header, a bit like a plugin breadboard.

    But female headers are typically 8 to 8.5mm high which means that with the 2.5mm pin spacer that means the module sits up to 11mm off the board. But I also use 5mm high low-profile or short female headers although I don't have any 2x20 in stock and make them up out of hacked non-stackable 2x8 and 2x4 headers. Messy. I can order the 2x20 short female headers at a good price from 4UCON but I need to order an MOQ of 1,000 and that takes at least 6 weeks. In the meantime I can also order some from a supplier as "short RPi female headers" in packs of 2 but they cost quite a bit more although I have asked for a quote. This is one of my dilemmas that I am in the process of addressing.

    Headers are helpful too for testing otherwise I would need an array of pogo pins to press onto to test all the pins. A standard header is important too and makes it easier to mix'n'match.

    So what do you think about the type of header? Socket or pin or none. Standard or short?


    That's a tough one. I'd actually prefer my board without headers since I was planning on installing a right angle male box header on port A and probably not populating the 100mil on port B. The 50mil are what I was planning on using to connect the p2d2 to my board, although I have been considering bringing port A to the edge of my board. Still not 100% sure on what to do as I'd like to be able to use a standard 40-pin ide to connect to a picobbler. All the more reason for me to get a second p2d2 I guess!
  • kwinnkwinn Posts: 8,697
    None or standard female would be fine for me. This first board is strictly for familiarization and prototyping.
  • It's a tough one. Whatever is ultimately decided, if you intend to supply pins/headers can mine please be left unsoldered? I plan to reverse mount and also have space for a small fan of 6mm height below the P2. I will need to see how best to fit it when I get it. I do like the idea of a low profile socket on your board but may still need to leave a gap. I have height issues in my case.
  • I prefer no header or pin (unsoldered bare board).
  • So it seems that I should just supply this without a header then? I can still get those standard socket headers and supply them loose I guess. Anyone who gets a P2D2 should resist the temptation to just solder directly to the module as that messes it up later on when you go to solder a connector on. The right-angle header on the A side (P0..P31) allows for a vertical mount for those pins and when I get my HyperRAM module then the B side will already be more than half used up even without a header.

    I'm thinking I will supply standard height female socket headers loose by default but I can solder them on if requested.
  • How much height do you think your HyperRAM board will add to the bottom of the board Peter? Is it a slim PCB?
  • It will be a thin half thickness 0.8mm PCB that is surface mounted directly to the bottom of the P2D2. But the bottom becomes the top normally when it is flipped and plugged in.
  • So ~ 0.8mm + height of regulator?
  • rogloh wrote: »
    So ~ 0.8mm + height of regulator?
    Well you have the bga pack and the regulator is a tiny package too, but I will check soon and get back.
  • Cluso99Cluso99 Posts: 18,066
    Peter,
    IMHO I wouldn't solder them so that the user can decide. If they are cheap enough, supply them tho as lots of people don't have easy access to cheapies.
    Secondly, soldering them will take you way too much time that could be better spent, and it will get boring pretty quick too with all those pins!
  • Cluso99 wrote: »
    Peter,
    IMHO I wouldn't solder them so that the user can decide. If they are cheap enough, supply them tho as lots of people don't have easy access to cheapies.
    Secondly, soldering them will take you way too much time that could be better spent, and it will get boring pretty quick too with all those pins!

    I've ordered some stuff from LCSC including those 2x20 headers which I will supply loose. But I need to make a jig that can check all the header pinouts without the header.
    btw - soldering is easy enough, especially when you use the manual reflow technique which after tacking the connector down, soldering up a few scattered positions, and then running down the connector on an angle with lots of solder and a hot iron!


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