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Parallax P2 Eval Board - Page 4 — Parallax Forums

Parallax P2 Eval Board

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  • cgraceycgracey Posts: 14,133
    Tubular wrote: »
    We use TPS7A49xx series. I went for a bit of a hunt, LP5907 looks reasonable, noise is an order of magnitude down vs NCP1114

    Input Voltage Range: 2.2 V to 5.5 V
    • Output Voltage Range: 1.2 V to 4.5 V
    • Stable With 1-µF Ceramic Input and Output
    Capacitors
    • No Noise Bypass Capacitor Required
    • Remote Output Capacitor Placement
    • Thermal-Overload and Short-Circuit Protection
    • –40°C to 125°C Operating Junction Temperature
    • Low Output Voltage Noise: < 6.5 µVRMS
    • PSRR: 82 dB at 1 kHz
    • Output Voltage Tolerance: ±2%
    • Very Low IQ (Enabled): 12 µA
    • Low Dropout: 120 mV (typical)

    Thanks, Tubular.

    That comes in the same footprint as what we've got planned, so we'll just change the BOM.
  • We're probably going to want to try other options too. Those 3 pin headers, together with ground posts, permit that.

  • dMajo wrote: »
    Chip,

    But I'll really like if you can add a few (let say four) MikroElektronica style click connectors (https://mikroe.com/click).
    I've noted that beside Microchip (which can be reasonable because they are partners) also other dev boards (fpga, arduino compatible, ...) start using this standard because of the numerous click-boards available.
    Perhaps your hdmi, vga, usb, ... daughter-boards can also use this standard. Both Parallax and MikroE can have benefits from this choice.

    +1

    I have suggested the same, some time ago. This is a great way of speeding-up product development. I already use these modules on another platform.

    Another would be a P1/P2 motherboard for the Tibbit Blocks. If this motherboard was designed with the same footprint as their own motherboard, we integrators can use their modules and enclosures (all available separately) to produce one-off devices that would resemble something that is mass-produced.

    Project Boxes

    Other parts for custom modules, etc.
  • Please, keep an eye at the fish, and another at the cat.

    Hyperrams and some of those 8-pin, fast quad spi, IOT, Pseudo (or whichever they are to be called) RAMs seems to live a little more confortable with 3.0 V power feed and signaling levels.

    The problem seems not to be exactly related to the speed of the memory cells themselves, but it has to do with the noise level they'll experiment internaly, at the interface registers exposed to the external world.

    Keeping some options available is an important factor in succeeding when trying to apply them.
  • P2 Eval Board looks really nice, I would love to get my hands on one!

    HydraHacker
  • W9GFOW9GFO Posts: 4,010
    edited 2018-11-03 03:23
    I also agree about the USB connectors, if they were rotated 45 degrees to face the back I think that would be ideal*. Having them stick out past the board edge like Phil said would be good too.

    Maybe those of us with lasers can collaborate (or compete) on an enclosure design.

    *Or don't and I'll try to prove Phil wrong about the impossibility of making an enclosure for it.
  • Soooo... Pricing and availability on these? I want one!!!
  • cgraceycgracey Posts: 14,133
    KaylaMarie wrote: »
    Soooo... Pricing and availability on these? I want one!!!

    Not sure, yet. It's two weeks away. Pricing is going to be $100-$200, probably. Maybe right in the middle.
  • KaylaMarie wrote: »
    Soooo... Pricing and availability on these? I want one!!!

    Welcome to the wonderful world of P2.
  • evanhevanh Posts: 15,126
    edited 2018-11-03 09:47
    [deleted]
  • cgraceycgracey Posts: 14,133
    It is almost done. The backside ground plane is going to be a great heat spreader.

    2018-11-03%2019_42_17-3D%20Preview.png

    2018-11-03%2019_41_03-3D%20Preview.png
  • !!!

    We need to begin add on boards soon.
  • evanhevanh Posts: 15,126
    cgracey wrote: »
    The backside ground plane is going to be a great heat spreader.

    Something for me to aim the paint stripper at. :D

  • cgraceycgracey Posts: 14,133
    evanh wrote: »
    cgracey wrote: »
    The backside ground plane is going to be a great heat spreader.

    Something for me to aim the paint stripper at. :D

    I think you could mount a giant Peltier and fan combo straight to the bottom of the board. It is quite featureless.
  • I look forward to getting my hands on the p2, however, I'm a little worried about the price $100-$200 seems high. Will there be more reasonable options available at later dates? My concern is related to the idea that I will not be buying indivdual chips, only completed boards. I have no interest in soldering chips to boards
  • W9GFOW9GFO Posts: 4,010
    cgracey wrote: »

    I think you could mount a giant Peltier and fan combo straight to the bottom of the board. It is quite featureless.

    Do you think a heat sink will be a common thing for people to be adding?

  • cgraceycgracey Posts: 14,133
    ti85 wrote: »
    I look forward to getting my hands on the p2, however, I'm a little worried about the price $100-$200 seems high. Will there be more reasonable options available at later dates? My concern is related to the idea that I will not be buying indivdual chips, only completed boards. I have no interest in soldering chips to boards

    We are paying $59 each for these prototype chips. Our final cost, once in production, will be less than a tenth of that. Even at $200 a board, we would lose money selling this initial batch.
  • cgraceycgracey Posts: 14,133
    edited 2018-11-03 23:29
    W9GFO wrote: »
    cgracey wrote: »

    I think you could mount a giant Peltier and fan combo straight to the bottom of the board. It is quite featureless.

    Do you think a heat sink will be a common thing for people to be adding?

    It should not be necessary, at all. Certainly, at 180MHz, which the P2 is designed to run at, no cooling is needed.
  • We are paying $59 each for these prototype chips. Our final cost, once in production, will be less than a tenth of that. Even at $200 a board, we would lose money selling this initial batch.

    I’m totally down with this price range. I couldn’t convince myself to buy a FGPA rig less because of cost but more because of my intense dislike of the dev environment for FPGA parts. “Real” hardware makes my real giddy though.
  • cgracey wrote: »
    W9GFO wrote: »
    cgracey wrote: »

    I think you could mount a giant Peltier and fan combo straight to the bottom of the board. It is quite featureless.

    Do you think a heat sink will be a common thing for people to be adding?

    It should not be necessary, at all. Certainly, at 180MHz, which the P2 is designed to run at, no cooling is needed.

    Those mounting holes on the diagonal, would they match up with common (60mm? 80mm?) fan holes? If not, could they be nudged inwards so that they do?

    For the overclockers...

  • Linear tech micro modules are nice, at least for lazy people. Something like the ltm4624..
  • cgraceycgracey Posts: 14,133
    Tubular wrote: »
    cgracey wrote: »
    W9GFO wrote: »
    cgracey wrote: »

    I think you could mount a giant Peltier and fan combo straight to the bottom of the board. It is quite featureless.

    Do you think a heat sink will be a common thing for people to be adding?

    It should not be necessary, at all. Certainly, at 180MHz, which the P2 is designed to run at, no cooling is needed.

    Those mounting holes on the diagonal, would they match up with common (60mm? 80mm?) fan holes? If not, could they be nudged inwards so that they do?

    For the overclockers...

    Good idea. I'll see about that.
  • octetta wrote: »
    We are paying $59 each for these prototype chips. Our final cost, once in production, will be less than a tenth of that. Even at $200 a board, we would lose money selling this initial batch.

    I’m totally down with this price range. I couldn’t convince myself to buy a FGPA rig less because of cost but more because of my intense dislike of the dev environment for FPGA parts. “Real” hardware makes my real giddy though.

    Yeah, Parallax is NOT based in China....

    What does it cost to take the missus out to dinner and how long does that last?

    Damn, I remember thinking I got a great deal on my first 20MB hard drive in 1985.....$600!!! :lol:

  • Cluso99Cluso99 Posts: 18,066
    edited 2018-11-04 02:12
    Nice board :smiley:

    IMHO mounting holes should be near the corners if possible. As they are, the board would rock although stick on buttons in the marked corners would work nicely.
    With some minor repositioning of components, here is a suggestion for holes marked red.

    BTW I like the idea of the holes matching fans for us overclockers :smile:

    2018-11-03%2019_42_17-3D%20modified.png
  • jmgjmg Posts: 15,140
    ti85 wrote: »
    I look forward to getting my hands on the p2, however, I'm a little worried about the price $100-$200 seems high. Will there be more reasonable options available at later dates? My concern is related to the idea that I will not be buying indivdual chips, only completed boards. I have no interest in soldering chips to boards

    I think there will be a more compact, and thus lower cost, module-use PCB released.
    More like P2D2 or FLiP (eg A 64 pin 0.9" FLiP-2 looks layout-feasible)
  • YanomaniYanomani Posts: 1,524
    edited 2018-11-04 02:35
    From the top view, it appears that diagonal directions are a bit congested, by the presence of many components and connectors at those regions.

    Perhaps something like those 40x40x20 mm (32 mm squared (45.255 mm diagonal) mounting holes spacing) can better fit, mounted at those holes that exists near the GND posts, or sure, as per Tubular's suggestion, slightly nudged inwards ones.

    https://noctua.at/en/nf-a4x20-5v-pwm/specification

    The linked model is spec'd at 5V, 0.1A and can be PWM'd too.

    Can both work as a necessary complement for overclockers, and, with appropriate power boosting, as a demonstration of P2' PWM capabilities.
  • jmgjmg Posts: 15,140
    cgracey wrote: »
    It is almost done. The backside ground plane is going to be a great heat spreader.

    Hard to see, but I think that adds GND and VCC options for an Oscillator module (good), but lacks the optional AC coupling cap needed for the higher spec (& lower cost) Clipped Sine Oscillators ?


    Regulators still seem to be older ones needing STKY diodes and a larger BOM & PCB area ?
    eg a TPS82130 (17V, 3A, integrated inductor) can slash the BOM and PCB area.
  • Chip...thank you for the response. I didn't realize the first run of chips were so expensive. Great to hear the next batches will decrease in cost. I'm just really looking forward to buying a lot of chip/boards.
  • jmgjmg Posts: 15,140
    edited 2018-11-05 22:34
    Cluso99 wrote: »
    BTW I like the idea of the holes matching fans for us overclockers :smile:
    Or even holes for heatsinks, like this one ?

    For this to mount-under, it would help to remove the solder resist on the bottom area.
  • RaymanRayman Posts: 13,805
    That's a nice looking heatsink. I wonder how effective it would be on top...
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