P2 Evaluation Board

I am wondering when a P2 evaluation board will be available for developers to test with. This question has been asked by two other people, but I haven't seen a response to it. Personally, I'm looking forward to trying out the P2, and run my validation tests on it. I also have several programs that I've run on the P1 that I like to try on the P2, and I have some P2-specific programs that I've written. Many people have posted that they have applications that they would like to run on the P2.

The more people that test the P2, the greater the chances of catching potential issues that it may have. It seems like Peter's P2D2 would serve the purpose of evaluating the P2. Does Parallax have an estimate of when the populated boards will be available?
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  • jmgjmg Posts: 12,618
    Dave Hein wrote: »
    I am wondering when a P2 evaluation board will be available for developers to test with. This question has been asked by two other people, but I haven't seen a response to it....

    The more people that test the P2, the greater the chances of catching potential issues that it may have.
    Of course.
    Dave Hein wrote: »
    It seems like Peter's P2D2 would serve the purpose of evaluating the P2. Does Parallax have an estimate of when the populated boards will be available?

    The P2D2 is a good, compact, modest power, P2 test vehicle. I think all hand-packaged P2s (that survived) are now on P2D2 boards & Parallax ran a P&P on the P2D2F rev, so they could readily run more of those, when the full package parts arrive, if they decide to.]
    Maybe Chip can send you one if they have any spares ?

    Peter was also doing a motherboard carrier for P2D2.

    Chip has also mentioned Parallax will do a more fully featured P2 board, but details are scant thus far.



  • cgraceycgracey Posts: 10,540
    edited October 9 Vote Up1Vote Down
    I suppose we probably have five chips left at Parallax, out of the original ten. A few more could go onto Peter's P2D2 boards. All current testers are using this board.

    Meanwhile, we are designing a very robust board for testing the P2 on. It has variable 3A switch-mode power supplies, as well as selectable 3.3 volt quiet regulators for each set of 8 I/O pins. It has a huge heat spreader on the bottom. This board will let us really determine the limits of the chip. I think this layout is probably a week from being done, hopefully less. We will need this board to do a lot of the data sheet work. We will make this available as a standard product. I will post images when we have something to show.
  • I'm happily still hammering on an FPGA.
    Money is a placeholder for cooperation
  • Yes, I have been doing some too.

    Happy to wait for the Parallax board. Right now, demands on my time are high enough that I do not make sense as a very early tester.

    Do not taunt Happy Fun Ball! @opengeekorg ---> Be Excellent To One Another SKYPE = acuity_doug
    Parallax colors simplified: https://forums.parallax.com/discussion/123709/commented-graphics-demo-spin<br>
  • jmgjmg Posts: 12,618
    cgracey wrote: »
    Meanwhile, we are designing a very robust board for testing the P2 on. It has variable 3A switch-mode power supplies, as well as selectable 3.3 volt quiet regulators for each set of 8 I/O pins. It has a huge heat spreader on the bottom. This board will let us really determine the limits of the chip. I think this layout is probably a week from being done, hopefully less. We will need this board to do a lot of the data sheet work. We will make this available as a standard product. I will post images when we have something to show.

    Sounds quite comprehensive, and good for data sheet work - but a regulator for every 8io's might spook some potential customers, who could think that level of regulator-sea is required to use P2 ?

    What variable regulators have you selected ?
    What is your Vin range target ?

  • Chip, thanks for the update. Sounds like a good plan. I believe there are 100 more chips coming soon. Do you know when you will get those?
  • The quiet 3.3V regulators are just for providing highly filtered power to groups of eight pins, so that analog signalling will be optimal. You can set the jumpers so that all the pins work off the main VIO supply, in case you don't want any of that special quiet analog stuff.
  • Sounds great!
    Maybe a Reset button,SD & flash,leds,switches/buttons VGA and RCA connectors like P123 :)
    Melbourne, Australia
  • cgraceycgracey Posts: 10,540
    edited October 9 Vote Up0Vote Down
    Yes, a reset button and a GND post. Each 8 I/O's will have their own 2x6 male header. If you need more than 8 I/O's, your add-on board can straddle two headers.
  • I would be happy to pay extra for a set of RCA's and VGA.

    Or... maybe that's one of the first add-on boards.

    Do not taunt Happy Fun Ball! @opengeekorg ---> Be Excellent To One Another SKYPE = acuity_doug
    Parallax colors simplified: https://forums.parallax.com/discussion/123709/commented-graphics-demo-spin<br>
  • cgraceycgracey Posts: 10,540
    edited October 9 Vote Up0Vote Down
    Yes, add-on boards can supply all those connectors.

    There are a lot of analog apps that we haven't thought of yet, so it is impossible to put everything useful onto one board. We don't know what we don't know.
  • Peter JakackiPeter Jakacki Posts: 7,868
    edited October 9 Vote Up0Vote Down
    My dev board will be designed to have the P2D2 plugged in and I guess I could provide additional power from the dev board itself. Here in the meantime is a proto dev board I'm putting together that has headers on either side of the P2D2 so that I can stack matrix boards or PCBs to easily access all the I/O. Otherwise I have pin headers for VGA and serial and I2C etc. I will also experiment with USB hosting but even this hand wired proto board is still very versatile. I like to have simple adapter cables for bulky connectors such as VGA and a dual row 8-pin R/A pin header keeps it simple. There's even room on the left side of this board for a variety of various Puppy modules that I have used in the past. That's one of my W5500 Ethernet modules up in the top right.

    This board is not meant to be anything like the final dev pcb though, just to get something in the meantime and help me think about what might be useful.

    @Bump - inserting images results in multiple copies of the link being inserted. I always have to clean it up back to one.
    30254602447_1574f52b15_z.jpg
    640 x 374 - 102K

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
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  • TubularTubular Posts: 3,295
    edited October 9 Vote Up0Vote Down
    So if you're going with 2x6 male headers, isn't that very close to Digilent pmod, which are female on the host board?

    There are lots of pmod boards already out there. The pmod boards have male 2x6 (8gpio) or 1x6 (4gpio) headers on them

    Several of our FPGA boards have pmod headers on them
  • cgracey wrote: »
    Yes, add-on boards can supply all those connectors.

    There are a lot of analog apps that we haven't thought of yet, so it is impossible to put everything useful onto one board. We don't know what we don't know.

    I'm good with that. Nice thing is we can just make 'em and share. Count me in.
    Do not taunt Happy Fun Ball! @opengeekorg ---> Be Excellent To One Another SKYPE = acuity_doug
    Parallax colors simplified: https://forums.parallax.com/discussion/123709/commented-graphics-demo-spin<br>
  • Tubular wrote: »
    So if you're going with 2x6 male headers, isn't that very close to Digilent pmod, which are female on the host board?

    There are lots of pmod boards already out there. The pmod boards have male 2x6 (8gpio) or 1x6 (4gpio) headers on them

    Several of our FPGA boards have pmod headers on them

    It seems there are a lot of pinout variations on those Digilent boards.

    I just want to do something like this:

    Pins
    1 2
    3 4
    5 6
    7 8
    9 10
    11 12

    1 and 2 = GND
    3..10 = P0..P7
    11 = VIO
    12 = 5V (USB)
  • And do that in groups? Or, just for a subset of I/O's?
    Do not taunt Happy Fun Ball! @opengeekorg ---> Be Excellent To One Another SKYPE = acuity_doug
    Parallax colors simplified: https://forums.parallax.com/discussion/123709/commented-graphics-demo-spin<br>
  • My dev board will be designed to have the P2D2 plugged in and I guess I could provide additional power from the dev board itself. Here in the meantime is a proto dev board I'm putting together that has headers on either side of the P2D2 so that I can stack matrix boards or PCBs to easily access all the I/O. Otherwise I have pin headers for VGA and serial and I2C etc. I will also experiment with USB hosting but even this hand wired proto board is still very versatile. I like to have simple adapter cables for bulky connectors such as VGA and a dual row 8-pin R/A pin header keeps it simple. There's even room on the left side of this board for a variety of various Puppy modules that I have used in the past. That's one of my W5500 Ethernet modules up in the top right.

    This board is not meant to be anything like the final dev pcb though, just to get something in the meantime and help me think about what might be useful.

    @Bump - inserting images results in multiple copies of the link being inserted. I always have to clean it up back to one.
    30254602447_1574f52b15_z.jpg

    Looks good, Peter.

    We figured on putting an extra micro USB jack on the base board for high-current 5V. Those DP/DM pins can route to P56/P57.
  • potatohead wrote: »
    And do that in groups? Or, just for a subset of I/O's?

    For each 8 pins.
  • jmgjmg Posts: 12,618
    cgracey wrote: »
    It has variable 3A switch-mode power supplies...

    Are those i2c programmable, or resistor-set variable ?
    Given the wide Power/operating P2 range, I've been looking into i2c regulators.

  • jmg wrote: »
    cgracey wrote: »
    It has variable 3A switch-mode power supplies...

    Are those i2c programmable, or resistor-set variable ?
    Given the wide Power/operating P2 range, I've been looking into i2c regulators.

    They will be settable with a screwdriver pot.
  • Each 8 pins works! That's going to allow for a lot of creative options.

    Looking forward to it. :D
    Do not taunt Happy Fun Ball! @opengeekorg ---> Be Excellent To One Another SKYPE = acuity_doug
    Parallax colors simplified: https://forums.parallax.com/discussion/123709/commented-graphics-demo-spin<br>
  • Anybody tested if the I/O can work in digital mode at 1.8V?
    That would be convenient in certain cases...
    Prop Info and Apps: http://www.rayslogic.com/
  • evanhevanh Posts: 5,912
    edited October 9 Vote Up0Vote Down
    Rayman wrote: »
    Anybody tested if the I/O can work in digital mode at 1.8V?
    That would be convenient in certain cases...

    Chip has said in the past that they're tuned just for 3.3 volt only.

    Ignoring analogue, digital inputs should be fine but output drive strengths will be reduced at 1.8 volts. They may still be useable. I have no experience myself.

    Expect big slew times that may require reduced bit rates and longer handshakes.

    EDIT: That was said some months back. Today I note Chip has already been experimenting with lower VIO on the real silicon - https://forums.parallax.com/discussion/comment/1448241/#Comment_1448241 And that is using analogue too!

    Money is a placeholder for cooperation
  • jmgjmg Posts: 12,618
    cgracey wrote: »
    jmg wrote: »
    cgracey wrote: »
    It has variable 3A switch-mode power supplies...

    Are those i2c programmable, or resistor-set variable ?
    Given the wide Power/operating P2 range, I've been looking into i2c regulators.

    They will be settable with a screwdriver pot.

    Hmm..
    Before you finalize the Board design, I'd suggest you talk to the OnSemi product manager for Regulators & Digital Potentiometers (POTs)

    There is obvious appeal to using OnSemi PSU parts, but their lineup is a confusing mish-mash of old part codes, old part codes in new package, and multiple part codes and poorly documented parts... (sigh) - you want to avoid dead-end parts, & choose a good spec, long life product.

    Examples :
    I find a CAT5140ZI-50-GT3, digital POT & EEPROM, good price in 50k, but more in 100k, and no i2c address pin ?
    Not much sign of life in the whole OnSemi POT series... Microchip do have dual-NV-pots that could adjust 1v8, 3v3 rails.

    - a digital pot is one means to allow run-time control of Vcc/MHz envelope & works with any ADJ Linear and SMPS regulators.
    The other approach, is to use an i2c SMPS regulator.

    They do have i2c SMPS parts, in quite good prices, tho in BGA packages, and show one package variant (NCV6356) in a nicer DFN14 3.0 x 4.0 mm, but only in a 2x price Automotive qualifier. There is a non-automotive part code NCP6356 visible on the net, but suggests not the same package ?!
    Usually, you can design in the higher price and switch to the other in production, less clear here if that is possible ? (aarrgh!)

    In non i2c parts, they have something like NCP3170A/B OnSemi 4.5~18V 3A PGood 2500 $0.3333, but only in non-thermal SO8, & that needs compensation parts. So it comes in 'best' ranking somewhat behind the
    AOZ2261QI-15 8A 2.7V~ 28V, 22-QFN (4x4) 26 mΩ / 12 mΩ typ at 12V Digikey stk 1448 49c/3k


    OnSemi mention factory settings, so they may have just the right parts a right-part-code away ?
  • jmg wrote: »
    cgracey wrote: »
    jmg wrote: »
    cgracey wrote: »
    It has variable 3A switch-mode power supplies...

    Are those i2c programmable, or resistor-set variable ?
    Given the wide Power/operating P2 range, I've been looking into i2c regulators.

    They will be settable with a screwdriver pot.

    Hmm..
    Before you finalize the Board design, I'd suggest you talk to the OnSemi product manager for Regulators & Digital Potentiometers (POTs)
    ...

    Digital pots would be complicated, wouldn't they? I need something that I can just turn with a screwdriver and check on a digital multimeter.
  • jmgjmg Posts: 12,618
    cgracey wrote: »
    Digital pots would be complicated, wouldn't they? I need something that I can just turn with a screwdriver and check on a digital multimeter.
    Have you wired the pots in 'H' config, so wiper noise / wiper open cannot give illegal Vout ?

    Yes, digital is slightly more to set up.

    The CAT5140ZI-50-GT3 comes in a MSOP8, so you can easily layout for both manual & digital.
    One fish-hook, is the 5140 has no address pin, but I think reverse SCL/SDA trick can work ok on 2 parts.

    The appeal here, is the P2 can then adjust its own Vcc's, to suit what MHz it is expecting to use.

  • jmg wrote: »
    cgracey wrote: »
    Digital pots would be complicated, wouldn't they? I need something that I can just turn with a screwdriver and check on a digital multimeter.
    Have you wired the pots in 'H' config, so wiper noise / wiper open cannot give illegal Vout ?

    Yes, digital is slightly more to set up.

    The CAT5140ZI-50-GT3 comes in a MSOP8, so you can easily layout for both manual & digital.
    One fish-hook, is the 5140 has no address pin, but I think reverse SCL/SDA trick can work ok on 2 parts.

    The appeal here, is the P2 can then adjust its own Vcc's, to suit what MHz it is expecting to use.

    But if you adjust too far downward, or get the supplies into too great a disparity, the P2 will not be able to communicate, anymore, and all will be lost.
  • jmgjmg Posts: 12,618
    edited October 9 Vote Up0Vote Down
    cgracey wrote: »
    But if you adjust too far downward, or get the supplies into too great a disparity, the P2 will not be able to communicate, anymore, and all will be lost.

    The i2c SMPS parts have defined limits, and an i2c Pot can set the limits on the 'H' wiring. (3 resistors + pot) - same as your trim pot will be (hopefully) legal (safe) at both ends.

    Disparity is trickier, and the user would have to know what 'too great' was there.

    That suggests there is a Vcore/Vio polygon for valid SOA - do you know what the corners of that polygon are yet ?
    If that's a big issue, in the analog domain, some modest crosstalk could be deliberately added, with cross coupling components.
    that means MAX Vio setting pulls up MIN Vcore, but MIN-MIN is allowed.
  • TubularTubular Posts: 3,295
    edited October 9 Vote Up0Vote Down
    if you use a regulator with a voltage divider (2 resistors) around a feedback node, as is very standard, you can also connect that node to a P2 output pin via a midrange resistor. When that P2 output is floating, it doesn't affect the node, and you get nominal (eg 1.8v? 1.85v? ) regulator output.

    You set the midrange resistor value such that, if the P2 hard outputs 0v or 3v3, the maximum tug still keeps the regulator output as per the datasheet range, eg 1.65 to 2.0 volts. Hardcore types can reduce that resistor for more range if they really like

    Normally this approach can introduce a bit of noise at the feedback node, but in P2's case you can output with a stiff analog 75 ohm DAC. Possibly even dither. It would work a treat and costs a pin and a resistor, provided you have a voltage dividing regulator arrangement.

  • jmgjmg Posts: 12,618
    Tubular wrote: »
    ...
    You set the midrange resistor value such that, if it hard outputs 0v or 3v3, it only tugs that node such that the output can only be in the datasheet range, eg 1.65 to 2.0 volts. Hardcore types can reduce that resistor for more range if they like
    A P2 DAC would work, but I was trying to avoid fully consuming P2 pins for voltage config. i2c is usable for other connected parts.
    Chip has indicated ~1.1V is a min and 2.0 is the MAX spec, for the core.


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