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michaelmorris

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Posts posted by michaelmorris

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    1 hour ago, SkyBound said:

    I had the same issue and built a switch box like you describe, it worked well, so don't see any issues there...obviously a more complicated way would be to have it switch via software.... ? Not something I could do...

    Thanks. I can see no need at present for a switching via software.  Eventually, I hope to convert all the focusers to stepper motor-based systems as part of a more automated set up.  Because I plan to have a dual imaging rig, at that stage software-based switching would be desirable, but that is probably a year or two down the line.

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    The hand box for the focuser is now starting to take shape and I'm now looking at the final configuration of the housing for the Arduino, power supply and motor driver board.

    The plan it to use the focus controller to operate either the the Meade Zero-image shift  focuser on the back of the C9.25 or the Skywatcher Accufocuser on the refractor.   The Meade focuser uses a mini jack whilst the Skywatcher uses an RJ11 plug.  But how to wire this up?  I presume the simplest way would be to simply wire the sockets for both focusers into the same pair of terminals.

    However, this creates a problem. I would like to be able to leave both focusers plugged in all the time. But, if I do this, sending a signal will surely operate both focusers simultaneously.  So what I really need is a simple selector switch that diverts the signal to one of the two sockets. Does his sound logical?

    If this is a viable solution, is this the sort of switch I should be getting?

    http://www.maplin.co.uk/p/10a-toggle-switch-spdt-b-jk28f

    Thanks

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris
    incorrect picture

    I've been mucking about with 'Fritzing' electrical design software ( http://fritzing.org/home/ ) to try to get my head around how I'm going to wire this all up.  

    I've by no means mastered the software (I can find half the components I need), but I've put in some proxies and notes where I can't find what I'm after.  Once the final components have arrived, my mate Dave has 'volunteered' to help with soldering it all up. :)

     

    final dc motor layout.jpg

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted

    On 20/01/2017 at 20:12, michaelmorris said:

    I've got some pots, but accidentally ordered ones with switches (Doh!). I assume I just ignore the two pins at the back of the pot and just use the front three.  Is this correct?

    Playing with the system, they don't seem to make a vast difference to the motor speed, it varies between almost stationary and slow.  The movement of the focuser motor is a bit jerky with the pots connected.   Would getting pots without a switch give a me greater number of degrees of rotation and would this give a greater range of speeds?

    Okay, wiring fault spotted.  All now working as I would hope.

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    On 18/01/2017 at 17:48, brown_rb said:

    Yes 10k pots, any will do.

    http://www.ebay.com/itm/2Pcs-10K-OHM-Linear-Taper-Rotary-Potentiometer-B10K-Pot-Knob-XH2-54-Wire-Cable-/191941882370

     

    I've got some pots, but accidentally ordered ones with switches (Doh!). I assume I just ignore the two pins at the back of the pot and just use the front three.  Is this correct?

    Playing with the system, they don't seem to make a vast difference to the motor speed, it varies between almost stationary and slow.  The movement of the focuser motor is a bit jerky with the pots connected.   Would getting pots without a switch give a me greater number of degrees of rotation and would this give a greater range of speeds?

    Thanks

     

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    I'm now investigating the best way for me to physically mount all this electronics hardware.

    For me, I think the best set up might be to put the Arduino and driver board in one box attached to the mount head.  This would include connections for 12v power, USB and the control/power cables going to focuser motors.  Connected to this would be a separate small box used as a hand controller.  This would include potentiometers and momentary switches, along with related resistors.  Hopefully, this hand controller could be re-used when I eventually upgrade to stepper motors and a stepper motor control board (using MyFocuserPro2).  Does this sound sensible?

    If the above is a feasible idea, I would need at least five wires between the hand controller and the Arduino in the main box (5v, ground and three signal cables).  I assume this could be best achieved by using a single multicore cable between the hand controller and the main box.  I would propose using a DE9 (RS232-type) connector to attach the hand controller to the main box.  Is this the best option?  If yes, can anyone recommend the most suitable multi-core cable for this connection lead?

    Thanks

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted

    The resistors arrived yesterday.  I followed Robert's excellent and clear step by step (i.e. idiot proof) instructions and wired it all up using patch cables and a breadboard.  And for the moment of truth ...

    It works!!!!!! :hello2::icon_biggrin::hello2::icon_biggrin:

     

    Thanks Robert, you are a true hero! :headbang:

    Next to arrive is the 12v to 9v thingy, then put it all in a box.

     

    • Like 1

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted

    7 minutes ago, SonnyE said:

    Michael and RB,

    Here is a link to some basic symbols you are encountering as you slowly sink into the mire of electronics. :wink:

    http://www.electronic-symbols.com/electronic-electrical-symbols/basic-electrical-electronic-symbols.htm

    I'm on my way to an electronic focuser as we speak. Parts on order as of today. I just needed a few confirmations from a friend who is using complete remote on his set-up in frozen North Dakota, U.S.A. One thing I changed about my plans is to go with a direct drive to my fine focus adjuster on my two-speed Crayford. I was concerned about the side loading a belt drive might impart to the tiny shaft (2.7 mm). Matthew (N.D.) has his direct coupled to his fine adjust shaft and assured me the tiny Unidirectional gear motors have plenty of torque to do the adjusting. So the side loading became a non-issue.

    The motors I ordered are the 28byj 48, 5 volt, with Uln2003 Driver Board for Arduino. Same format as my friend has on his focuser.

    Onward! Into the fog! :wacko:

    Thanks for the link. I wish you well with your project.

    • Like 1

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted

    2 minutes ago, brown_rb said:

    They wire to A0 as shown in circuit diagram :-)

    PushButtons_schem.jpg

    Thanks Rob

    I get parts of the diagram, but other bits are a bit of mystery to me.

    There are 3 x 1.2Kohm resistors and a 1Mohm resistor in the circuit and one end of the circuitis  attached to the 0 (Marked RXC) terminal on the Arduino. Is this correct? 

    Do the other ends of the circuit attach to the 5v and one of the GND terminals on the Power section of the Arduino?

    Also, what is the triangle of three lines of diminishing size symbolise?

    Sorry for the numpty questions, but I'm more or less a complete newbie at his.

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    The push buttons have now arrived so that I can operate the focuser when I'm next to the scope.  I've read through the myDCFocuser documents and I can't for the life of me work out where to wire them in. Help!

    Please bear in mind that I am to electronics what Jack Nicholas was to Greco-Roman wrestling!

    • Like 1

    Arduino focus control for DC AND stepper motors?

    in DIY Astronomer

    Posted · Edited by michaelmorris

    Okay, I've now ordered what I think is everything I need to make a basic test bench version of the myDCfocuser.

    • Arduino Uno
    • L9110S DC motor board
    • assorted jump cables
    • breadboard
    • 4p4c socket (to connect to the Accufocuser motor)
    • 9v battery connector (to power the Accufocuser motor)

    Have I missed anything? (or probably more accurately - What have I missed?)

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