P2D2 - An open hardware reference design for the P2 CPU

11516171921

Comments

  • jmgjmg Posts: 13,549
    rogloh wrote: »
    Yeah I see it in the schematic but on the last board picture it looks like it goes to 5V in the bottom right of the picture. Is the silkscreen covering something I'm not seeing?

    What is the purpose of the back powering diode ?
    Wouldn't users simply tie 5V and 3V3 supplies together if powering from 3v3 only ?
    Result is USB Switch is on, and Switcher is at 100% duty, so always on, and 3v3 LDO is either in saturation, or close to it,
  • rogloh wrote: »
    Glad to be of service. You better double check for any other cases where your schematic and layout mismatch.
    \

    I've been busy wrangling with Protel99SE for the past week and it has been crashing and corrupting the library files. I try not to get too flustered about something like this but I'm certainly not happy about it. The area where it became VCC instead of VIO was probably because I had a VCC fill in there and this was one of the last mods I did.



    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • roglohrogloh Posts: 1,068
    edited 2019-05-06 - 08:29:59
    jmg wrote: »
    What is the purpose of the back powering diode ?
    Wouldn't users simply tie 5V and 3V3 supplies together if powering from 3v3 only ?
    Result is USB Switch is on, and Switcher is at 100% duty, so always on, and 3v3 LDO is either in saturation, or close to it,

    It was just an easy way to back feed VIN with something close to 3.3V from VIO so as to not load up the 3.3V regulators, in the case of wanting a simple/passive 3.3V WiFi programming dongle cable to be attached to P2D2 programming header and be powered in-system. Just adds flexibility and is not mandatory, just optional.
  • Cluso99Cluso99 Posts: 14,974
    edited 2019-05-06 - 08:52:23
    @Peter,
    Great news the P2D2r2 is done, apart from the minor bug fix. Yes, I have found issues with ground and power planes with Protel. I’m still on an earlier Protel version although i keep thinking i should go to Protel 98. Then i think about my footprints and potential issues, and i just pull out the old laptop again ;)

    The Pi connections are a dog’s breakfast :( Seems they took a leaf from Arduino with it’s terrible connections. Why oh why do people design crappy connections instead of straight forward connections/connectors??? So thanks that the P2D2 has such nice sequential connections :smile:
    My Prop boards: P8XBlade2, RamBlade, CpuBlade, TriBlade
    Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
    Website: www.clusos.com
    Prop Tools (Index) , Emulators (Index) , ZiCog (Z80)
  • Peter JakackiPeter Jakacki Posts: 8,348
    edited 2019-05-07 - 05:51:08
    Well it got a bit late to press the send button yesterday so I am doing that this morning after a few more trims. The gerbers look good and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
    I don't need too many pcbs for the moment but it would be good to have extras for when the production chip comes out. The build time for 30 or less boards is 24 hours so I might go for 30 and DHL for ~$25 if I add the stencil for $6.

    I've just sent it off as default green mask of the moment, I can always do another run.

    P2D2R2-190506.png
    2793 x 1951 - 2M
    2793 x 1951 - 2M

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • jmgjmg Posts: 13,549
    ...and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
    ..
    We have used Black for boards that have thermal challenges, but it is not so easy to visually inspect, so for early samples Green is fine.
    Did you order 2Oz copper ?

  • Just default cheap and standard 1oz. But what's an ounce here or there between friends? 😁

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • Well done Peter. Looking forward to it. Midway through an adapter board to suit it.
  • Awesome, it's underway! :smile:
  • Excellent news Peter :smiley:
    My Prop boards: P8XBlade2, RamBlade, CpuBlade, TriBlade
    Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
    Website: www.clusos.com
    Prop Tools (Index) , Emulators (Index) , ZiCog (Z80)
  • Great news. You guys worked really hard on this one! On the side - I *might* be willing to donate my one and only P2 Dev Board - *IF* you think you can safely unsolder it and put it on this P2D2 board. I have seen it done, but you need the right hot-air desoldering equipment, and even then it is somewhat risky. Just a thought.
  • jmg wrote: »
    ...and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
    ..
    We have used Black for boards that have thermal challenges, but it is not so easy to visually inspect, so for early samples Green is fine.
    Did you order 2Oz copper ?

    The colour won't make a difference thermally, all soldermask is emissive in the far IR (a board with bare
    copper would be much less efficient at radiating heat than anything with soldermask). Soldermask is also
    important for receiving heat radiation in a reflow oven. Pretty much any organic material is highly emissive,
    any bare metal is not (which is why heatsinks and power resistors are anodized - the anodizing visible light
    colour is actually irrelevant)

    Personally I find dark green soldermask boring and dull, which may just be a novelty-seeking thing.
  • Got an email about 3 hours ago to let me know that the boards and stencil have been shipped. So it looks like I will get it this Friday even though I only sent the artwork off lunch time yesterday. Unbelievable!
    Now I just have to order the parts but they should be here Monday.

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • Peter, could you publish a new BOM for the latest layout? The last one I have is a few months old.
    Infernal Machine
  • Publison wrote: »
    Peter, could you publish a new BOM for the latest layout? The last one I have is a few months old.

    I will order the parts today so I am in the process of converting the raw bom across along with Mouser part numbers etc and I will post that as soon as I'm done.

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • SuracSurac Posts: 2
    edited 2019-05-12 - 09:35:10

    - is it possible to buy the P2D2 board anywhere?
    - where can i buy a P2 chip?

    thanks for your time
  • Peter JakackiPeter Jakacki Posts: 8,348
    edited 2019-05-13 - 02:20:23
    My parts order to Mouser was sent a little late so now I have to wait until Mouser processes and ships the order. I'm hoping that despite the fact that it will be Tuesday here when that happens that I can still get the parts this week. Since I have a stencil I will immediately make up one pcb and check it quickly so that I can run off at least 10 pcbs although I think I have about 15 P2ES chips on hand.

    I will post the BOM shortly and from there I can calculate a price. For anyone who wants/needs one there are some that have been waiting a while so they are at the top of the list. But hold off holding your breath until I complete my checks and make sure I have a working product first. But feel free to place a tentative order for one by posting here and the price will still be reasonable even though I badly need to cover my costs (except for Chip if he wants one) :)
    2766 x 1762 - 985K
    2701 x 1724 - 824K

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • Definitely send one to Chip :smiley:
    My Prop boards: P8XBlade2, RamBlade, CpuBlade, TriBlade
    Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
    Website: www.clusos.com
    Prop Tools (Index) , Emulators (Index) , ZiCog (Z80)
  • Peter, glad you got your boards back. At first glance it seems okay and that silk numbering around pins is more readable now too, though the photos are not in perfect focus so it's a bit hard to tell. Are you still satisfied with the quality? Any PCB production issues that are noticeable?

    Can't wait to hear how it goes once you build up your first one and get it working, then get a hold of one myself with any luck!

    Cheers,
    Roger.
  • Peter JakackiPeter Jakacki Posts: 8,348
    edited 2019-05-13 - 15:04:58
    @rogloh
    Hmmm, I didn't have much time so I just used one of the photos from my phone which normally are ok but I must have held it a bit close this time and the edges blur. Here's another shot I just did under less than ideal lighting.

    The pcb production looks to be very consistent and high quality. Don't worry, I've got one of the first ones earmarked for you, I know you've been waiting a while :)

    p2d2r2-1.JPG
    3796 x 2613 - 1M

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • Nice photo. There's a lot of versatility packed in there now with USB and the various clocking options. Looks great!
  • How many of these will be available? Have they all been spoken for?
  • I believe that Chip wanted to order about 1000 or 1500 units (corrections anyone?!).
    If those numbers are off, he definitely wanted to order a lot more than the first engineering sample since this should be the final product anyway.

    J
  • @cgracey

    https://forums.parallax.com/discussion/170139/p2-final-release-date#latest
    We will have 2,400 production chips in late August. Hopefully, there won't be any problems with them.
    
  • Peter JakackiPeter Jakacki Posts: 8,348
    edited 2019-05-15 - 00:36:01
    David Betz wrote: »
    How many of these will be available? Have they all been spoken for?

    I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.

    Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.


    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • We need a couple down here. Is there a subscription service?
  • David Betz wrote: »
    How many of these will be available? Have they all been spoken for?

    I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.

    Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.

    Thanks. Once all of the people who missed out on the Parallax boards get theirs I will put in a request. I haven't had much time for P1 or P2 lately but I hope to get back to it soon.
  • David Betz wrote: »
    David Betz wrote: »
    How many of these will be available? Have they all been spoken for?

    I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.

    Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.

    Thanks. Once all of the people who missed out on the Parallax boards get theirs I will put in a request. I haven't had much time for P1 or P2 lately but I hope to get back to it soon.

    Me too please Peter,
    But I think it is better if the "professionals" get theirs first,
    Since I'm really a newbie to Spin....

    I come and browse the forums and read a lot of the threads,
    and it just gets me excited and ideas start whirling around in my one watt
    :D :D :D
    Sadly my soldering skills are as good as my swimming...
    I swim like a brick lol :D :D

    I don't mind paying for parts, shipping and your time too if it helps :)

    Thanks
  • I popped down the coast and got my friend who has some fresh solder paste for the stencil to make up a pcb for me. Here is the intermediate result, I have to do some power up checks nice and slow and talk to the P2 via the 5-pin connector for the moment until I work out how to put USB serial code into the EFM8 chip. Obviously I seem to have the wrong reset switch on there and an led is missing but that doesn't matter at the moment. If all goes well I will have a quantity of boards ready next week.

    3448 x 2424 - 1M

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    --->CLICK THE LOGO for more links<---
    P2 +++++ TAQOZ INTRO & LINKS +++++ P2 SHORTFORM DATASHEET
    P1 +++++ Latest binary V5.4 includes EASYFILE +++++ Tachyon Forth News Blog
    Brisbane, Australia
  • Very good and I was wondering if your parts had arrived by now. Now the fun part can start - take your time, no rush. I hope it all works out nicely.
Sign In or Register to comment.