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Parallax A-7 FPGA Boards - who's interested?

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  • I somehow read that the $200 offer for the A7 was backed, and now Parallax is offering A9's for $400. My previous posts refer to the $200 offer. If the price is $400, then I have to decline. I recognize that the boards are still given, but my pockets don't go as deep, unfortunately.
  • TubularTubular Posts: 4,702
    edited 2016-04-11 19:41
    The A7's will still be available, but in a few weeks time.

    They're being fixed (known minor pullupdown required, some ws2812 leds replaced) and 'latitude tested'.

  • cgraceycgracey Posts: 14,152
    edited 2016-04-11 14:51
    Tubular wrote: »
    The A7's will still be available, but in a few weeks time.

    They're being fixed (known minor pullup required, some ws2812 leds replaced) and 'latitude tested'.

    You mean pull-down, right?

    I think one of the pads adjacent to the A1 pin is actually ground. If you could get in there, it might be possible to slip an 04O2 resistor in. I don't think I could do that, but I suspect you might be able to.
  • RaymanRayman Posts: 14,641
    Are the new A9 boards ready to ship?
  • Yes, pulldown. Actually I think all 3 neighboring balls are gnd.

    The 0402 thing would probably work, if you could get and iron under there reliably.
  • jmgjmg Posts: 15,173
    samuell wrote: »
    Definitely I would be interested in having the FPGA loaded with the core for the P2, provided that we have a fully functional, 16 core equivalent. Is that the case? All 16 cores included?
    The A7 is able to fit only a subset of a complete P2 + Pins, otherwise there was no need to move to the A9
    There was a comment a while back on what fitted, but that could have changed with more recent builds.

  • cgraceycgracey Posts: 14,152
    Tubular wrote: »
    Yes, pulldown. Actually I think all 3 neighboring balls are gnd.

    The 0402 thing would probably work, if you could get and iron under there reliably.

    Do you have a hot-air pencil. Maybe some flux, an 0402, and some fine stream of hot air would do it. You'd need one of those fiber-optic cameras to see if it worked out.
  • jmgjmg Posts: 15,173
    cgracey wrote: »
    Do you have a hot-air pencil. Maybe some flux, an 0402, and some fine stream of hot air would do it. You'd need one of those fiber-optic cameras to see if it worked out.

    The risk of a short would seem high ?
    The external resistor has a convenient GND area to anchor one end to.
    May not be as invisible as 'buried 0402', but it is a lower risk path, & who cares about invisible ?

  • ErNaErNa Posts: 1,752
    edited 2016-04-12 06:59
    to repair smd I use old fashioned solder paste (lower melting point). I would try it this way: bring some solder past to the tips of the resistor to insert and have them dried, so the flux becomes solid. Place those prepared smd to the target place and reflow with an air gun. (not like this one: thinkgeek.com/product/60b6/
  • The thing about the wire is you can always pull it out, as required, or if its made good contact you can leave it in and work with the other end where everything's easier

    One idea I had today though, might be to use a 4 resistor resnet, soldering 1 end resistor in, but still being able to pull the slab out from the other end.

    Once the batch of A7 boards turn up I'll get a feel for the range of heights. My A7 was about 0.5mm above the PCB, but there might be a bit of variation. 0.5mm really limits what you can do




  • jmg wrote: »
    samuell wrote: »
    Definitely I would be interested in having the FPGA loaded with the core for the P2, provided that we have a fully functional, 16 core equivalent. Is that the case? All 16 cores included?
    The A7 is able to fit only a subset of a complete P2 + Pins, otherwise there was no need to move to the A9
    There was a comment a while back on what fitted, but that could have changed with more recent builds.
    Thanks, jmg! I'm not exactly interested in the sheer number of pins, nor if they are smart. I would be interested in the processing capability, which is hopefully far more than a P1. If I can fit 16 cores, or even if not but nevertheless they are significantly faster, I'm satisfied. I'm planning to use this for VGA applications and power processing. Hence my prime number calculation experiment.

    Kind regards, Samuel Lourenço
  • evanhevanh Posts: 15,915
    Tubular wrote: »
    We'll leave the test code installed and running on the A7's. The test code will either be running on top of a P1V, or a P2, depending on where Chip's images are at by then. That'll save using PX.EXE which might be an issue with other operating systems (but probably not)

    PX is ported - http://forums.parallax.com/discussion/162989/lazarus-port-of-px
  • Ok, great.

    Have you had a chance to run it with an A7 or A9, Evanh?

  • evanhevanh Posts: 15,915
    Yep, tested with Ozzies Button-LED demo on the A9. It's the only thing I've used the A9 for so far since I don't have Windoze to run PNut.
  • Were the A7 boards able to be fixed?

    Thanks
    Tom
  • Yes Tom, when the PLL resistor is applied to that A1 pin they come right.

    The WS2812 leds work nicely as a real-time test
  • RaymanRayman Posts: 14,641
    Congrats on fixing those. Is the plan to ship back to Parallax for sale?

    Looks like get 8 cogs and full 512kB of RAM w/A7 and latest build.
  • If I remember correctly, in April ten or so of us signed to purchase some flavor of FPGA board (see the beginning of this thread).
    Then it was discovered that they needed to go somewhere (in the southern hemisphere, perhaps) to have rework done (see the middle of this thread).
    Then the thread died (see near the end of this thread).
    I think twm was trying to find out if anything ever actually happened. I would like to know as well.
  • cgraceycgracey Posts: 14,152
    If I remember correctly, in April ten or so of us signed to purchase some flavor of FPGA board (see the beginning of this thread).
    Then it was discovered that they needed to go somewhere (in the southern hemisphere, perhaps) to have rework done (see the middle of this thread).
    Then the thread died (see near the end of this thread).
    I think twm was trying to find out if anything ever actually happened. I would like to know as well.

    That was Tubular that was going to (and did!) rework those boards whose PLL's didn't work. All done now. I think he's got 18 of them. If you are interested, one might be yours.
  • TubularTubular Posts: 4,702
    edited 2016-09-13 04:10
    "All done now" is a bit of an exaggeration. Right now we're at 10 14 operational.

    We had to change the earlier 0603 technique a bit, but I'm confident well get to at least 13, perhaps 17 operational. One board 'hiccups' and I don't hold much hope for it

  • Thanks Lachlan. I'll take one.
  • Ok, let me know when you have fixed Ken up, and I'll ship one from here. Email me your new address

    Its free DHL shipping, for Smorgasboard alumni...

  • Woah, cool, thanks! Just PMed Ken.

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