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Another Fine Product Discontinued? — Parallax Forums

Another Fine Product Discontinued?

PublisonPublison Posts: 12,366
edited 2013-12-02 11:38 in General Discussion
The Propeller Servo Controller, (at least the current one), is in it's final build. Only 5 left. I hope there is another in the works. They are handy little boards.

http://www.parallax.com/product/28830

I'm speculating that they will come out with a new one with different translator chips.

Comments

  • Martin_HMartin_H Posts: 4,051
    edited 2013-11-27 06:46
    Publison wrote: »
    I'm speculating that they will come out with a new one with different translator chips.

    I should hope so. The propeller as a servo controller with USB and TTL input with an external power jack is basically a killer app for the propeller chip.
  • ercoerco Posts: 20,256
    edited 2013-11-27 07:16
    Always sorry to hear EOL news. Meanwhile, Pololu's Maestro line of SC's is a nice alternative, and 40% off all weekend.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-11-27 07:32
    I suppose the PSC was nice since it had the servo headers on the board, but really just about any Propeller board could be used as a servo controller.

    If Parallax makes a new version I hope they make it so you can use 28 servos instead of just 16.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-11-27 07:54
    @Duane Degu
    If you buy two, you can cover 32 servos.. 4 more than your 28. I suspect that after 16 servos from one board, the demand for a single board solution drops way way down.

    I have a little controller for 8 servos, and I've never used all 8.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-11-27 08:42
    Loopy Byteloose wrote: »
    @Duane Degu
    If you buy two, you can cover 32 servos.. 4 more than your 28. I suspect that after 16 servos from one board, the demand for a single board solution drops way way down.

    I have a little controller for 8 servos, and I've never used all 8.

    Actually just about any Propeller board could drive 32 servos, but you need some way of keeping P28 - P31 free while it boots up. No need for two boards.

    And of course people will need more than 16 servo. It takes 18 to make a pile of Popsicle sticks walk (well, almost walk).

    Fortunately Paul K took pity on me after seeing my failed hexapod and sent me one of his kits.

    I often use all 32 I/O pins on the Prop and I think it's too bad the PSC didn't have the other I/O pins accessible.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2013-11-27 08:52
    'Tis a shame, but maybe they're coming out with a new and improved replacement, or maybe considering an add-on board for the QuickStart or something that has the servo connectors and power tap.

    On the number of servos: 18 is a better minimum than 16. With 16 you can't drive a 3 DOF hexapod, for example, and adding another PSC for just two servos seems wasteful. Each added servo increases the cost a bit, so there needs to be some practical number that works for 95%+ projects while keeping down costs. I'd probably opt for a board that supports 24, breaking out the power for the servo terminals in at least two sets, and offering a jumper to select the power source for those sets. That brings it in line with Pololu's top-end servo controller, which is a very handy board.

    That said, servo controllers are something of an odd duck with limited appeal unless there's firmware or examples for making it easier for people to program all those servos. Lynxmotion's approach was to include several types of gaits for their legged robots, even providing inverse kinematics software to simplify the task. It sold robot kits for sure. The majority of people would find it difficult to properly code various walking styles for multi-legged robots, snakes, and other unusual projects.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2013-11-27 09:53
    When I wrote Servo32 it was initially named because you had access to all 32 of the I/O's and you could assign a servo to any one of them. The fact that you could control ALL 32 servo's at once was a bonus which later became a challenge just to see how many servo's a Propeller could potentially drive all at once. The driver was modified into a version that could drive 48 servo's using 1 COG with some external logic ICs. That idea worked but was not pin limited by the number of available I/O's. Using the same driver X3 (still requiring 1 COG) a single Propeller could comfortably drive 144 servos.

    Reference:
    http://forums.parallax.com/showthread.php/84187-Will-the-servos-Parallax-sells-work-from-a-pulse-directly-from-the-Propeller?p=583652&viewfull=1#post583652
  • PublisonPublison Posts: 12,366
    edited 2013-11-27 09:57
    Beau Schwabe (Parallax) wrote: »
    When I wrote Servo32 it was initially named because you had access to all 32 of the I/O's and you could assign a servo to any one of them. The fact that you could control ALL 32 servo's at once was a bonus which later became a challenge just to see how many servo's a Propeller could potentially drive all at once. The driver was modified into a version that could drive 48 servo's using 1 COG with some external logic ICs. That idea worked but was not pin limited by the number of available I/O's. Using the same driver X3 (still requiring 1 COG) a single Propeller could comfortably drive 144 servos.

    Reference:
    http://forums.parallax.com/showthread.php/84187-Will-the-servos-Parallax-sells-work-from-a-pulse-directly-from-the-Propeller?p=583652&viewfull=1#post583652

    I loved that thread and object! But I could not bring myself to purchase 144 servos to see it work. :) (Or the power Supply).

    :)
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2013-11-27 12:09
    There's no telling what the future holds for a new PSC module. :innocent: We designed that unit during a time when digital servos were starting to become really popular and introduced some issues with the level translation. All in all there were several reasons for discontinuing the product at this time. If we ever release a comparable product we'll of course want to make sure it can handle all common servos and not just those we carry. The fact is there are a lot of options out there and as some have brought up, not everyone has a need to control 16 or 32 servos, but it is fairly easy to add servo headers to several of our Propeller-based boards and add that capability.
  • Ken GraceyKen Gracey Posts: 7,392
    edited 2013-11-27 12:13
    This particular product was being made in China for Parallax. The minimum order quantity (1K units) would last us a year, so it didn't make any sense to continue to place such orders. We looked at making it here in Rocklin, but the costs would've gone up so much that you would not have bought it anymore. We have to pick and choose where our dollars go, and when we have to make decisions where we consider products like this one against Propeller 2 design costs and foundry runs we won't make any short-term decisions that put cash in inventory.

    We can post all the files here if anybody wants to pick up the manufacturing of this product. You can have them, free of restrictions!
  • ercoerco Posts: 20,256
    edited 2013-11-27 12:49
    @Ken: If there was sufficient demand, could Ari & SimplyTronics save the day again, as he did with the ServoPal? http://forums.parallax.com/showthread.php/144135-ServoPal-Discontinued?p=1149100&viewfull=1#post1149100

    Or should I hoard the last 5 units ( I don't even have one!), squirrel them away for 20 years, then send you one for your archives, as was the case with the Stamp Activity Board? :)

    Who am I kidding? I'll be dead long before another 20 years goes by. These girls of mine (or their boyfriends) will run me ragged and kill me off long before then.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2013-11-27 14:04
    How about a thru-hole breakout board for the QS, with taps for at least 18 headers, and room for the level shifters and screw terminals for power? Let us solder the thing, like how many Arduino shields are sold (yes, I know there's some added support issues with self-soldering). There's no absolute need for a separate servo controller board, all things considered. Now you're just talking about unpopulated panelized boards, and a kit of parts, yes?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2013-12-02 11:38
    Gordon,

    That sounds like a good idea but we'd probably run into the same issues of having to order 1000 or cost issues here. It sounds like something that an open-source community could easily do and you could even have a pool for the boards to be ordered. :nerd:
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