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16  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 16, 2014, 11:06:06 pm
Code:
The zenith and azimuth columns for the rows you highlighted look credible for a position in the southern hemisphere that was within about eight degrees of the equator, with dawn slightly before 06:00 and dusk slightly before 19:00. You could verify them yourself just by checking whether each pair of figures accurately reflects the position of the sun at that time.

is there any software to check it so i can verify answer.
17  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 15, 2014, 11:39:00 pm
Now all points are cleared. How to check Whether postion i calculated is pointing toward the sun.Here iam attaching output xls i got from nrel .

If i am wrong let me know.
18  Using Arduino / General Electronics / Power Isolation Circuit Arduino on: July 15, 2014, 07:22:38 am
Dear all,

I am trying to build power isolation circuit between USB and Power supply.

Like in ardunio UNO  they used lp2985-33DBVr are connected.
I am using 7812 & 7805  7805 to  turn on MC  and 7812 for sensor input.
I need isolation between USB power supply & 7805 When it powered through USB. Is there any link where i can copy the schematic.
19  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 15, 2014, 06:59:52 am
if i am not wrong . I cant also express what i have understood due improper sentence

Please answer with yes or no. If not why??
These points are expected or not
1) zenith and azimuth gives sun direction right ya wrong??
2) altitude give sun elevation angle right ya wrong??
3)for dual axis tracker i need to consider azimuth along x dir that circular and altitude angle y direction for vertical motion.
The respective angle for day is attached in below . it relevant to one day. ?? Please let me know whether i calculated right or wrong.
formula taken from herehttp://www.susdesign.com/popups/sunangle/altitude.php


Quote
You need to know your current position and the current time. You need to calculate the direction of the sun at that position and time, for example as an azimuth angle and zenith/elevation angle. You need to position your actuators to point your device in that direction. You need to repeat this periodically so that the device tracks the sun as it moves. I'm sorry if it sounds patronising to explain something so basic after you've spent this much time working on a solar tracker, but from the way you keep asking about it I'm not at all sure you have grasped the concept.

current time : is calculate from RTC
current position?: still not confirmed
i considered azimuth and altitude angles to determine position.
since actuator as no feedback , i am using inclinometer to adjust angle from reference 0~360 degree  and 0~90 degree.

20  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 15, 2014, 05:54:25 am
My question Here is Which are the angle need to consider & why.
How could track sun based on These angle.

As links attached above says i.e zenith & azimuth angle use to measure direction of sun & altitude to postion.Which are angle need to consider & why???

In all arduino based tracker they used LDR and moving along zenith and azimuth . Since i am using inclinometer  , how considered angle
21  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 15, 2014, 01:33:20 am
after all.

http://www.susdesign.com/popups/sunangle/altitude.php

I understood that altitude/ elevation gives exact position of the sun. Which i converted to my inclinometer angle
The altitude angle is calculated as follows:

Altitude =asin( [cos (L) * cos (D) * cos (H)] + [sin (L) * sin (D)])
Converted angle is

sun_pos=90-altitude; in degree.


where:

Al = Solar altitude angle

L = Latitude (negative for Southern Hemisphere)

D = Declination (negative for Southern Hemisphere)

H = Hour angle

If i am correct these relation works. let me know if i am wrong here,

2) Now we know zenith, azimuth which represent direction of sun & altitude represent sun position .

My question
1) which are angle need to be consider for the sun position for dual axis tracker
2) When to actuate the motor/actuator???
3)@ which situation limit switch are triggered  for dual axis tracker.

Here i have also attached output file.



22  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 14, 2014, 11:41:05 pm
My location is INDIA ,
12.9667° N, 77.5667° E
Code:
You don't "find" the position of the sun from that - it is the position of the sun, expressed as azimuth and zenith angles. It is the answer to the question of which direction do you need to point your solar collector, or whatever it is that you want to track the sun.
I cant understand this statement
Below link gives elevation angle.
http://en.wikipedia.org/wiki/Solar_zenith_angle
http://www.pveducation.org/pvcdrom/properties-of-sunlight/elevation-angle
http://www.susdesign.com/popups/sunangle/altitude.php

Actually i am getting output from Nrel C code.

Julian Day:    2452930.312847
//L:             2.401826e+01   earth heliocentric longitude [degrees]
//B:             -1.011219e-04 degrees earth heliocentric latitude [degrees]
//R:             0.996542 AU earth radius vector [Astronomical Units, AU]
//H:             11.105902 degrees observer hour angle
//Delta Psi:     -3.998404e-03 degrees
//Delta Epsilon: 1.666568e-03 degrees
//Epsilon:       23.440465 degrees
//Zenith:        50.111622 degrees
//Azimuth:       194.340241 degrees
//Incidence:     25.187000 degrees
//Sunrise:       06:12:43 Local Time
//Sunset:        17:20:19 Local Time
23  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 14, 2014, 07:07:50 am
If that case ,
how can determine the sun position. In below code
http://kokoraskostas.blogspot.gr/p/include-timer.html
why he adjusting  tracker position to zenith and azimuth angle. Can you elobrate so i can understand proper manner .

is there any relation that gives sun postion depend on zenith and azimuth,

If i am wrong, Once we know Direction of sun how can we find sun position.


Quote
I suspect you have misunderstood what azimuth and zenith angles are. They give you a direction relative to your location. If you calculate them for the position of the sun, they give you the direction to the sun. Having calculated them for the sun's position you don't "determine sun position" from them - they are the answer, expressed as an azimuth and zenith angle.
24  Using Arduino / Project Guidance / Re: Dual axis tracker design on: July 14, 2014, 06:43:59 am
Now currently i came to stage where i found zenith and azimuth angle. I calculated those angle and compare with calculated upto  50 years from now, based on above links. i got offset 0.1 degree~0.5 degree some time.

My problem is i dont know how to use this angle to determine sun position.
check this animation
http://astro.unl.edu/classaction/animations/coordsmotion/altazimuth.html
I am confused with how this angle being taken in calculation. because various people different angle for calculation.

SO my question is how could i take these angle adjust my tracker position???
25  Using Arduino / Project Guidance / Dual axis tracker design on: July 14, 2014, 05:34:30 am
Dear all,
I am trying to design dual axis tracker using arduino due/mega. Here i am attaching  output table got from arduino mega for  
http://www.pveducation.org/pvcdrom/properties-of-sunlight/elevation-angle
http://www.pveducation.org/pvcdrom/properties-of-sunlight/declination-angle
http://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-time

 above formula i used to get Mc zenith and Mc azimuth on  arduino megA controller.

The zenith and azimuth i got from below calculator
http://www.nrel.gov/midc/solpos/spa.html



For dual axis tracker i am using  
2 linear actuator(24v,3A,400~600mm stroke length & 10000N load capacity) for N-S & E-W angle tracking.
Inclinometer1 (0~90deg,0~5v analog) for N-S direction
Inclinometer2 (0~360deg,0~5v analog) for E-W direction
2 limit switches /reed switches for stopping motor when desired position reached.

Now my question here
1) how to use zenith and azimuth angle in dual axis tracker??
2) if i use zenith and azimuth angle as for example in table attached around 12:30 it goes to 330 degree is it right or wrong.
3)Any change in the equation to be made to determine sun position.
4) if any help me with pseudo code like how can make it work will be appreciable.

Code:
Move_azimuth()
{
if((Azimuth_calc-Azimuth_inc)>=1.0 ))
  {
     Motor_action=REV;
     }else
     {
          Motor_Action=FW;
      }
     
 if(Limit_Switch==1&& Azimuth_calc==360)
 {
  Motor_action=Stop;
 }             
             
}

Move_zenith()
{
if((zenith_calc-zenith_inc)>=1.0 ))
  {
     Motor_action=REV;
     }else
     {
          Motor_Action=FW;
      }
     
 if(Limit_Switch==1&& zenith_calc==360)
 {
  Motor_action=Stop;
 }             
             
}


26  Using Arduino / General Electronics / Re: SCHEMATIC ANALYSIS on: July 14, 2014, 03:21:14 am
Any one share there what changes need to make here
27  Using Arduino / Microcontrollers / Selection of arduino board on: July 14, 2014, 12:10:34 am
Dear all,

I am looking for 32 bit controller in arduino platform. I found arduino Due only one model in 32 bit controller. Is my program / project involve double precision floating  point calculation Which micro controller suit.
Is there any other controller in cheaper price which do double precision floating point calculation,
The arduino mega / due uses more no of pins than actual application so i need controller with min IOs , 10 analog ios, do double precision floating point calculation.

Please suggest me relevant model available, if yes share link to purchase
28  Using Arduino / General Electronics / SCHEMATIC ANALYSIS on: July 11, 2014, 01:37:30 am
Dear all,

previously i used interface board to communicate all pins of arduino. Here i am attaching two image actual/ mc . actual represent interface board that takes all pins from arduino boards and get connected to arduino pins. Now, i am replacing interface / arduino board with my board where i am using all schematic involved on UNO board.

I need help to review the schematic MC image. Let me know what are additional parameter , values of passive/active parameter to be changed to work successfully.

Here i have doubt in power isolation. here i have not used isolation between main power and USB. can you let me how can do that. if any circuit please share image of it.
 all my sensor requires 12 v inputs and output are 0~5v analog.
i used 5 v regulator for LCD /keypad since when i tried with only arduino board i found power is not efficient to drive LCD.
29  Using Arduino / Programming Questions / Re: DS1302_clock_burst_write function problem on: July 09, 2014, 11:10:41 pm
Check below code. This code has worked out for me. I have attached library for your reference with example codes
30  Using Arduino / Programming Questions / Re: DS1302_clock_burst_write function problem on: July 09, 2014, 07:42:24 am
Can you share output & complete code that your trying, Previously i tired with ds1302 it worked fine
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