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using BS2 to control 6V and 12V actuators — Parallax Forums

using BS2 to control 6V and 12V actuators

trookstrooks Posts: 228
in BASIC Stamp
I have designed and written all the software command and control code for a unique system using BS2 modules with XBees acting as RF UARTS.  At present I can run simulations that use only LEDs as indicators for actual solenoids/actuators.


I now need some kind of hint/pointer/clue as to how I can get from those 20ma LEDs being turned on and off to the actual control of heavy duty solenoids and actuators.  It is a long way from a 20 ma I/O pin to actuating a 14 ft/lb solenoid and my efforts to get there have only released much magic smoke.


Any and all help will be much appreciated.


I have searched as best I can and have found nothing in the thousands of threads to get me pointed in the right direction

Comments

  • tomcrawfordtomcrawford Posts: 1,129
    edited 2015-07-26 17:02
    Here is a pointer to a typical thread that discusses that:
    BASIC Stamp AND Solenoid
    Edit: I took a close look at the thread I referenced and found a couple of wrong things.
    1. "What's a Microcontroller", referenced by Mike Green, at least my copy (2.2), doesn't actually say anything about solenoids.2. The link given by Professor Chaos to the Nuts and Volts Column 6 doesn't work any more.
    But Loopy's MOSfet advice *is* right on.  The L293D from Parallax is good for up to 600mA and includes the diode on the output side.
    EndEdit
  • trookstrooks Posts: 228
    tomcrawford
    July 26 edited July 26 Posts: 0FlagVote Up0Vote Down Here is a pointer to a typical thread that discusses that:
    BASIC Stamp AND Solenoid
    Edit: I took a close look at the thread I referenced and found a couple of wrong things.
    1. "What's a Microcontroller", referenced by Mike Green, at least my copy (2.2), doesn't actually say anything about solenoids.2. The link given by Professor Chaos to the Nuts and Volts Column 6 doesn't work any more.
    But Loopy's MOSfet advice *is* right on.  The L293D from Parallax is good for up to 600mA and includes the diode on the output side.
    EndEdit

    Tom,
    Thanks so much.
    I may have been entering my search criteria wrong.  Using BS2 and Relay seems not to have been a good choice.


    As for #1.) - I have that book and did not find what I need in it.
               #2.) - Sometimes the Professors advise is a bit too far behind the times<Grin>
    I have always found Loopy's advice to be 'right on'.


    Using your search criteria led me to the real eye opener of an optically isolated MOSfet switch.  Back in the Dark Ages of medical electronic devices optical isolators were used in abundance.  It just never occurred to me to use one to control a switch.


    I am going to start replacing LEDs with Part# PVDZ172N from International Rectifier and/or the L293D from Parallax.


    Thanks Again,
    trooks






  • PropGuy2PropGuy2 Posts: 360
    I have used the Texas Instruments SN75468 High-Voltage, High-Current Darlington Transistor Arrays, as a driver chip with good success.  They have good specs for what you are going to be using them for, plus you can parallel the outputs to get more drive current.  As always, use good engineering practice when designing with power solenoids: back diodes and voltage isolation as needed.
     
  • trookstrooks Posts: 228
    PropGuy2,
    Thank You a whole bunch for the tip and some specifics about the TI driver chip. 
    It's a good thing I always drag my feet when it comes to spending money or I would have already ordered stuff<G>.
    I keep telling my mechanical engineer partner to build in a few levers or even a pulley or two where speed is not critical and we could have less of those hulking actuators<VBG>.  He is doing as bit better.  At least we got those scavenged Caterpillar 18V actuators out of our prototype.




  • DavidlovesobotsDavidlovesobots Posts: 1
    Hello, I am trying to learn more about how to plot x and y with stepper motors, specifically the algorithm that tells the motors where to go, I need basic examples of the code on PBASIC, can someone point me in the right direction. thnx
  • Duane DegnDuane Degn Posts: 10,588
    Davidlovesobots,

    You'd probably be better off starting a new thread rather than adding your question to this one.

    Since your question here is nearly the same as the one in your PM, I'll respond here.

    I'm pretty sure there are some examples of PBASIC code to control stepper motors around but I don't know where they are.

    I personally use the Propeller. While I've done a lot of work controlling stepper motors with the Propeller, my code is presently an absolute mess. I'm too busy with other projects right now to clean it up. What I have worked on is available from my GitHub:

    https://github.com/ddegn/CncController

    The code is in Spin and PASM. A lot of the code has to do with operating the OLED display I'm using in the project.

    There should be code to control steppers in a linear motion and code to control steppers in circular motion but it would take me a while to figure out which program does what.

    While I don't think the Basic Stamp is an optimal controller for stepper motors, I'm pretty sure there are examples of using the Basic Stamp to control multiple motors. At the top of the first post in my index (see my signature) is a link to Rich's forum search page. The is what I use to search the forums. It might help you find an example of PBASIC code to control multiple stepper motors.
  • DigitalBobDigitalBob Posts: 1,513
    If your looking for just straight on/off control may I suggest relays from MPJA. They have an 8 channel relay for $13 and it is opto isolated so it will work well with your Led simulation. You have to look under. Ardurino and then compatible sensors
  • 72sonett72sonett Posts: 82
    trooks wrote: »
    ...I now need some kind of hint/pointer/clue as to how I can get from those 20ma LEDs being turned on and off to the actual control of heavy duty solenoids and actuators.
    Instead of an LED use an NPN transistor (open collector) to drive a relay, with the relay you can switch the actuator at 220 VAC if need be, or use a ready made relay module for less than US$3.00, e.g.
    3550.JPG

  • 72sonett72sonett Posts: 82
    Or use Parallax' own relay board:
    https://www.parallax.com/product/27115

    27115.png?itok=boF3QYDg
  • PublisonPublison Posts: 12,366
    72sonett wrote: »
    Or use Parallax' own relay board:
    https://www.parallax.com/product/27115

    27115.png?itok=boF3QYDg

    Now that's the spirit, plug Parallax products!


  • Steph LindsaySteph Lindsay Posts: 767
    ....and here is some BASIC Stamp example code for it:

    https://www.parallax.com/downloads/single-relay-board-basic-stamp-code

    We also have a version that interfaces to eight relays at once:

    https://www.parallax.com/product/27113
  • trookstrooks Posts: 228
    I am grateful to all that have contributed to this thread.

    The postings about plugging Parallax products caused me to go back and review for new things Parallax is offering since I last did a complete review and there it was.

    I now have an order in for a supply of solid state relays from Parallax. I will be using them to drive the off-board relays out in the mechanical stuff.

    The pessimistic optimist or the optimistic pessimist in me is going to leave the thread open until I get them and solder them in and run my testing and testing and a bit more testing.

    Once we have the product built and a name copyrighted and a demo video or two goes viral Y'all will understand the need for sooo much testing.
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