Author Topic: KenPro antenna rotor  (Read 1469 times)

FM5AB

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KenPro antenna rotor
« on: August 19, 2014, 03:05:33 PM »
I have an Kenpro rotor that i have use for ham radio satellite tracking It will be great for me to use it with sun tracking heliosat ardino program for tracking the sun.

The position of the rotor (elev and az) is give by a dc voltages 0 to 3.6 v (easy to use with ardino)

For the comand to the rotor In have 4 lines to put to the grownd for activate the motors (up downd right and left) (ok for ardino)

So, I have to read the clock
to compute Az and elevation
convert Az and elev to a number between 0 an 3.6
compare this number to the value given but the rotor (actual position 0 to 3.6v)
and give the orders (pin low) for turning in the good direction !

I am new in Ardino and I am not sure to make the soft successively without help !

Sorry for my bad English !!!




Gabriel

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Re: KenPro antenna rotor
« Reply #1 on: August 22, 2014, 06:50:48 PM »
Hello FM5AB and welcome to the forums!

It sounds like that Kenpro rotor will make the mechanical side of things a lot easier. If it works out, maybe other people can follow your example.

"So, I have to read the clock"
to compute Az and elevation"
Both of these are already done in the Sun Harvester program, so you shouldn't have to do anything there, unless you are using a different clock than I do.

"convert Az and elev to a number between 0 an 3.6"
I think this arduino function should help with that. http://arduino.cc/en/reference/map
Az min would be -180 and Az max would be 180
Alt min would be -90 and Alt max would be 90

"compare this number to the value given but the rotor (actual position 0 to 3.6v)
and give the orders (pin low) for turning in the good direction!"
This probably won't be too bad. I would probably write a test program without the sun tracking stuff just to work out the bugs. If you put everything in a function, you can then easily just paste your code into the existing sun harvester program. I can show you where to do this once you get to this point.



FM5AB

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Re: KenPro antenna rotor
« Reply #2 on: August 23, 2014, 12:50:22 PM »
Tkanks for your reply Gabriel, finaly, it is not so difficult to make the soft for Ardino Board, it is quite done.
i am waiting for the hardware from ur boutique !

I have olso the possibility to change the DC motor for a stepper, it seem possible by this way to use your soft.

For starting the Kenpro I have to put the pins at earth, this take only 2.2 mA but the problem is that I have 15 V on the kenpro pins certainly dangerous for the output pins of the Ardino.
May be I have to add a transistor between Ardino and Kenpro ?



jean-Pierre FM5AB

Gabriel

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Re: KenPro antenna rotor
« Reply #3 on: August 29, 2014, 07:11:28 PM »
Hi Jean,

Sorry about the lateness of this reply. I read your post, but kept forgetting to reply. I have actually been super involved with designing and redesigning 5 different circuit boards. Also, I completely redone the heliostat design I have been working on.

Thanks for your order! I think it is already in France, so hopefully it won't be too much longer before it gets to you. 

If you can swap the DC motors for stepper motors, it might make things a lot easier. As long as they are powerful enough, they should do fine. Just make sure you don't use more than a 12v power supply. Otherwise the motor will probably get too hot.

I suppose a transistor would work. They also have something called a Logic Level Converter too. https://learn.sparkfun.com/tutorials/using-the-logic-level-converter
The one at the link doesn't go up to 15V, but maybe they do make such a thing?

FM5AB

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Re: KenPro antenna rotor
« Reply #4 on: December 18, 2014, 07:12:03 AM »
Hi Gabriel,

Finaly I have put your stepper motor in place of the dc ones inside my kenpro antenna rotor.

All is ok but I have to increase by  x 8  the reduction factor (normaly 2706)

Step is 200

Have you an explanation ?

Thanks for your help

Jean Pierre FM5AB


Gabriel

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Re: KenPro antenna rotor
« Reply #5 on: December 18, 2014, 07:42:06 AM »
Hi Jean,

It sounds like your driver board is set to 1/8 stepping, which is fine. Most driver board have different "step settings" (not the right term, but I can't think of the correct one right now) which increase the precision of the stepper motor. So instead of having 200 steps per revolution, it now has 1600.

Hope that helps,
Gabriel

FM5AB

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Re: KenPro antenna rotor
« Reply #6 on: December 20, 2014, 04:49:05 AM »
Thanks for your relpy Gabriel , the problem is that I am using your Sun Harvester Driver Board V1 [193], I have check that if I put a gear reduction of 1 the motor (buy from you) dont make a complet turn for 360 of input....
not a big problem, but i don't understand !

JP FM5AB