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P2 -- easy to prototype without dev board? — Parallax Forums

P2 -- easy to prototype without dev board?

cbmeekscbmeeks Posts: 634
in Propeller 2
One of the things I love about the P1 is that it is super easy to slap it in a breadboard and get it working with very little effort.

Regarding the P2, will it be just as easy? I know it's a SMD part. But, I have some "SMD to DIP" converter boards. I would like to just buy a couple P2 chips and build my own prototype board.
The official dev board looks nice but it's a little pricey for me at the moment. (i.e., I've bought some parts for an Apple II+ and I've blown my fun money...lol)

I guess I'm asking, what kind of minimum setup will it need to get it going?

Also, any idea when we can buy loose P2 chips?

Thanks!

Comments

  • David BetzDavid Betz Posts: 14,516
    Yes, it would be interesting to see a minimal P2 circuit like the simple one for the P1.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2019-10-23 12:47
    A bare P2D2 pcb should be suitable for what you want to do, but bear in mind that there are 64 I/O and no way you are going to get DIP footprint out of that. The P2D2 uses a 20x2 pin connector on each side although you could cheat and only plug in a single row on each side if need be. Depending upon where you live @Publison has some left-over bare pcbs too. I haven't worked out a price for my assembled P2D2s but they are definitely cheaper than the eval board.
  • cbmeekscbmeeks Posts: 634
    @"Peter Jakacki"

    Yes, a cheaper alternative would be great. Something that is very minimal and not geared towards a particular function.

    Concerning the DIP package...I actually have TQFP-100 to DIP boards! And yes, they are gigantic. lol

    What I would really like to do is design my own dev board. But to have a dev board ready ASAP would be nice too.

    Can you share some details on yours?
  • PublisonPublison Posts: 12,366
    edited 2019-10-23 13:34
    cbmeeks wrote: »
    @"Peter Jakacki"

    What I would really like to do is design my own dev board. But to have a dev board ready ASAP would be nice too.

    Can you share some details on yours?

    http://forums.parallax.com/discussion/168645/p2d2-an-open-hardware-reference-design-for-the-p2-cpu/p1

    22 pages of details. :)

    I can drop one in an envelope if you like.

  • jmgjmg Posts: 15,173
    cbmeeks wrote: »
    ... But to have a dev board ready ASAP would be nice too..
    As well as P2D2R2, I have a fork of that that skips the 40 pin headers to RaspPi pinout compatible, and some other moderate changes.
    This allows RaspPi boards to plug straight into the P2 Eval Board, and there are many LCD (i2c & SPI) Displays available that can then be used directly.

    Attached is the Pi-pinout changes (click for full width)

    Other tweaks are more choices on Oscillators, change linear regulator to Higher current/lower noise thermally spread & 4 layer for better cooling and lower noise.

    I've also ported an EFM8UB3 UART, that's waiting on Peter to confirm is ok on P2D2R2..
    Currently this handles a fast reset pulse, and allows testing at baud rates up to 12MBd (24M/N supported) - above 3MBd there are more stop bits

    Pi40Pinout_P2D2Pi.PNG
    1135 x 148 - 40K
  • RaymanRayman Posts: 14,646
    I think it may take some time to figure out what is the right stuff that most people are interested in a dev board.
    P2D2 is not bad. I'm wondering if HyperRam should come standard or not...
    Also, maybe a HDMI connector and perhaps at least holes for a VGA connector...
  • jmgjmg Posts: 15,173
    Rayman wrote: »
    I think it may take some time to figure out what is the right stuff that most people are interested in a dev board.
    P2D2 is not bad. I'm wondering if HyperRam should come standard or not...
    Also, maybe a HDMI connector and perhaps at least holes for a VGA connector...
    Larger things like HDMI and VGA are probably best going into the Larger P2 Eval ?
    I've seen VGA-USB cables (wires only, no electronics), but I'm not sure there is a standard there yet (and those may be fading) ?

    HyperRam is interesting, also possible are the QUADSPI So8 RAMs like the 4MBit/45MHz ISSI ones and the announced MRAMs to 16Mbit/108MHz
    That may want to wait until the bandwidths needed for the various Video Resolutions possible on P2 are shaken out a little.
    Peter has a stacker board with HyperRAM, that could be used for such tests.
  • evanhevanh Posts: 15,916
    The accessories boards are rather nice to work with. They cover most of those optionals already, including a HyperRAM+HyperFlash accessory. They could be used on other carrier boards too.
  • TubularTubular Posts: 4,702
    Its really great having the accessory boards already to go. It has certainly made testing and evaluation easier. I'd encourage anyone wanting to rapidly develop something to grab an accessory board pack before they sell out
  • David BetzDavid Betz Posts: 14,516
    Tubular wrote: »
    Its really great having the accessory boards already to go. It has certainly made testing and evaluation easier. I'd encourage anyone wanting to rapidly develop something to grab an accessory board pack before they sell out
    I did just that! I'm glad Ken warned us that they were running low.

  • frank freedmanfrank freedman Posts: 1,983
    Has anyone considered doing a board with PMOD interface(s) so that all the PMOD accessories already existing can be used as well?

  • Peter JakackiPeter Jakacki Posts: 10,193
    frank freedman wrote: »
    Has anyone considered doing a board with PMOD interface(s) so that all the PMOD accessories already existing can be used as well?

    As mentioned, my P2D2 dev motherboard will have a lot of this stuff built-in anyway but will also have compatible headers for these modules too. I will try to publish some details in the next few days.
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