Author Topic: East-West degrees  (Read 2284 times)

Emmpunkt

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East-West degrees
« on: July 22, 2013, 02:30:23 PM »
Hallo,
Does the east and west degrees have to be equal?
I mean symetrical?
I have problems to get  my heliostat to work.
The beam on my target is slowly moving from left to right.
I am not at home, so I cant send my setup...

My machine:
2 gear boxes with wormgears 100:1
Stepper motors with 200 steps, set to microstep 3200 steps ( 200 steps does the same result)
My limits are at -30 and +120 degrees, something like that.
If I drive the heliostat as suntracker with the terminal, the inputed degrees and the moved degrees on the machine
are correct.
But if I use the suntrackermode or the heliostatmode, the machine is not holding the correct angles.

Where can I doublecheck my coordinates? getlatlon does not work.
Where can I doublecheck the calculated angles?

Thanks M.


Gabriel

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Re: East-West degrees
« Reply #1 on: July 22, 2013, 05:52:25 PM »
Hi Emmpunkt,

I'm not sure what your first question is asking? "Does the east and west degrees have to be equal?"
If you are referring to the maximum and minimum software limits, the answer is no, the angle values don't have to be equal.

If your machine is moving to the correct altitude and azimuth values when you manually input them, then I think we can narrow down the problem to just a few possibilities.

The first would be like you said, the latitude and longitude coordinates might be wrong. If the getlatlon site isn't working, you could try using a GPS if you have one.

I oftentimes use Google Earth to find latitude and longitude coordinates. If you go to Tools >> Options, you will even find an option to display the latitude and longitude values in decimal degrees under "Show Lat/Long". That way you don't have to convert them yourself. Then you can just travel to your house and read the displayed coordinates.

If you send me your address, I can double check it for you. For a location in Germany, you should have a latitude about +50 degrees and a longitude about +10 degrees. A common error is to accidentally use a negative value where you should have put a positive one.



Another possibility is that you have the time set incorrectly. Maybe go through the instructions again. http://www.cerebralmeltdown.com/setting-the-time-on-the-real-time-clock/



Double checking the calculated angles in another program can actually make things a lot more confusing because you can easily make a mistake when inputting your settings in that program as well. I do have this program PC based program here that you might be able to use. http://cerebralmeltdown.com/forum/index.php?topic=361.0
If you have a smart phone, you should be able to find applications for it that will display that altitude and azimuth of the sun. Since most smart phones have a built in GPS and should automatically have the correct time, it is less likely that you will accidently use the incorrect values.

A few more random thoughts...
You might try getting the sun tracking to work first. If that works, then heliostat mode should also work.
Have you tried resetting the Arduino after the beam has drifted to see if it ends up where it is supposed to be after the reset has finished?
Are you sure you have the machine aligned correctly? If you are reasonably certain you have everything else setup correctly, you can put the machine in sun tracking mode and then adjust the altitude and azimuth until it points at the sun.
Which Arduino are you using, the Uno or the Mega?

Those are my thoughts on the issue. Let us know how it goes.

Thanks!
Gabriel


Emmpunkt

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Re: East-West degrees
« Reply #2 on: July 23, 2013, 12:14:42 AM »
Hallo Gabriel,
sorry my english, it was late and i was using a Tablet-PC 8)
But i think it is better than Google Translations.....

Yes, that was meant with "Equal"

My problem with the coordinates is, that i donīt know which format is the right one.
On my GPS are 122 different formats for coordinates. Is WGS84 right?
I canīt find anything in your documentation.
I used 50.88015 ,7.55799 for it. This should be 50km east of Cologne.

I think the Time i have set is correct, but iīm not shure if i understand everthing right you wrote in " http://www.cerebralmeltdown.com/setting-the-time-on-the-real-time-clock/ "
I will attach a snapshot of a Team-Viewer session where you can see my Desktop- and the Arduino Time.
Timezone is +1 and we have Daylight saving time in Europe

The Arduino is a Mega.

I do aligning the machine with the Lipstickcontainer method. I made a Plastiktube for it, 20cm long, should be accurate enough.

Thank M.


Emmpunkt

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Re: East-West degrees
« Reply #3 on: July 23, 2013, 12:19:40 AM »
Sorry, forgot my Setup....
Code: [Select]
{   0  ,    2 ,       100 ,       1 ,     0  ,    0  ,   0  ,      0  , -27  ,      100 ,    -1    ,   0    ,  0    ,   0   ,    0 ,  -49.5,  -49.5,  -25,    145,   60 }

Gabriel

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Re: East-West degrees
« Reply #4 on: July 23, 2013, 06:10:19 PM »
I had no idea there were so many different GPS formats! Anyway, it sounds like the coordinates you are using are correct.

Double checking the time is easy.
First just download the Set_RTC_Time Arduino program located near the top of this page.
http://www.cerebralmeltdown.com/setting-the-time-on-the-real-time-clock/

Once it has been uploaded to the Arduino, open the serial monitor and make a note of the displayed GMT time. If the displayed time is the same as it is on this page http://wwp.greenwichmeantime.com/, then you have set the time on the RTC correctly. If not, well then that is most likely the cause of your problem.

By the way, in the TeamViewer session, did you click the "Activate Simulation Mode" button at the top right side? If you don't, then it pulls the values from the Arduino. What we instead want it to do is to display the values calculated by the computer.

Also, about how fast did the beam of light drift away from the target when you tried it?


Gabriel

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Re: East-West degrees
« Reply #5 on: July 23, 2013, 06:13:09 PM »
I forgot to mention it, but make sure you are looking at Standard Time near the top of this page http://wwp.greenwichmeantime.com/, not GMT +0:100

Emmpunkt

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Re: East-West degrees
« Reply #6 on: July 24, 2013, 01:28:01 AM »
Sorry, forgot to answer this:
Quote
Have you tried resetting the Arduino after the beam has drifted to see if it ends up where it is supposed to be after the reset has finished?
After a reset it is pointing to the same spot, changes nothing.

I will check the Time, but i think it is correct. The movements arte not large enough for a wrong time.
I found an App for my Phone that calculates the Sunposition, and it seems to be right. So i ordered a Laserpointer today to measure the angles (over a longer distance). Maybe my Wormdrives are not exactly 100:1 (Italian Product ;) )

Quote
Also, about how fast did the beam of light drift away from the target when you tried it?
The Distance to the Target is about 10m. It travels about 50cm in 5 hours. This is less than 1 degree in an hour.

Unfortunately the Sun is not shining today.
By the way, how can i disable the deleting of the Targets? (Reset to 0,0)
I dont want this, cause it happens accidently many times.

Gabriel

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Re: East-West degrees
« Reply #7 on: July 25, 2013, 05:58:56 PM »
50cm in 5 hours at 10m isn't necessarily great, but at the same time it isn't terrible. It does sound like it could be a mechanical issue.

I'm not sure it is possible to "accidently" reset the targets to (0,0). As long as you don't have the "Serial Monitor Control" switch turned on when you turn on Joystick control mode, it shouldn't ever happen.

What I think could be happening (if you don't have the potentiometer attached) is it is getting random reading from where the potentiometer is supposed to be and then switching between target groups because it keeps getting different readings.

You can fix this easily by going to the "Target Control" tab in the Arduino IDE and adding this line of code...

Code: [Select]
   targetsUsed = 1;

underneath this code.

Code: [Select]
   //CHANGES TARGET GROUP BASED ON POTENTIOMETER READING
   if (analogReading>0){targetsUsed = 1;}
   if (analogReading>200){targetsUsed = 2;}
   if (analogReading>400){targetsUsed = 3;}
   if (analogReading>600){targetsUsed = 4;}
   if (analogReading>800){targetsUsed = 5;}

I think that should fix it, but let me know if it doesn't.

Thanks,

stepper121

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Re: East-West degrees
« Reply #8 on: August 11, 2013, 05:25:25 AM »
Or you could just ground pin A2 this set the target to the first one as the analog pin will not change the.


Emmpunkt

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Re: East-West degrees
« Reply #9 on: August 13, 2013, 01:23:06 AM »
I dont think that it is a Target switching problem.
First i had a Poti on it, then i changed it to a 12 Position Switch.
Now there is a "FS20" Modul connected. (FS20=wireless Homeautomation by ELV).

Quote
As long as you don't have the "Serial Monitor Control" switch turned on when you turn on Joystick control mode, it shouldn't ever happen.

I think this is my fault!

By the way: Is it "Normal" that the arduino resets when i open the Serial Monitor?

M.

Gabriel

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Re: East-West degrees
« Reply #10 on: August 13, 2013, 07:10:10 AM »
Yeah it is normal for the Arduino to reset every time the Serial Monitor opens. It can be really annoying if you aren't expecting it. There is a way you can prevent this from happening.
http://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection
The downside though is that you won't be able to upload programs to the Arduino with the reset disabled.