hello every one
I designed a solar tracking system using DC linear actuator
but I don't know how to move the solar panel to a known angle
How to move actuators to the desired angle
Hi, @ahmed_osama
Welcome to the forum.
Please read the post at the start of any forum , entitled "How to use this Forum".
Why do you need a GPS, you can simply use some LDRs and get it to track the sun real time.
Is it a single axis tracker?
If so you will only need two LDRs or light sensors and a controller, plus some sort of driver circuit to go between the controller and the actuator.
Can you please tell us your electronics, programming, arduino, hardware experience?
Thanks.. Tom... 
does it change location?
The above is irrelevant. You don't need a GPS, irrespective of whether you move or not. Using a GPS is just trying to make things harder than they should be.
Very simple trigonometry. Post a diagram with measurements, showing how the solar panel and actuator are arranged.
Hi,
You don't have to know the angle with a light sensing tracker.
Google..
arduino solar pv tracker
There are single and dual axis trackers for you to research.
Can you please tell us your electronics, programming, arduino, hardware experience?
Tom...
Does your linear actuator have position feedback? You can't point to a known angle unless you can figure out the current angle.
yes have feedback
So you know how long the actuator is, and how far the mounting points are from the hinge. That gives you the length of three sides of a triangle. Use those lengths to calculate the current hinge angle. If the "known angle" is larger than the current angle, make the actuator longer. If the "known angle" is smaller than the current angle, make the actuator shorter.
I need arduino code to know how long the actuator
You need to know the minimum length of the actuator, and the maximum length of the actuator. The difference between these two measurements is known as the stroke.
You can get these measurements from the datasheet of the linear actuator, or you can do an experiment and measure the dimensions yourself using a tape measure or other suitable measuring equipment
The length at any time is going to be the minimum length plus some fraction of the stroke. You will get that fraction from the feedback mechanism of the actuator.
We need more information from you.
All you have told us so far is that you have a DC linear actuator, and that it has feedback of some sort.
this is the data sheet of motor
I use the regular model
because i need latitude and longitude to know the position of sun
Does the solar panel change locations or move about ?
Does your installation move, or will there be lots of them? I can't think of another reason to use GPS. For a static installation you can just hardcode the Lat Lon information.
Furthermore, GPS won't tell you which way the system is pointing, so lat lon isn't helpful without more data.
Which of the three feedback systems does your actuator have?!?
Reed Switch: 48 pulses per inch
Optical Interrupter: 125 pulses per inch
Variable Resistor: 10k Ohms
Note: The first two are RELATIVE position sensors. You will have to drive the actuator to one limit or the other to get absolute position. The variable resistor style is probably an absolute position.
No, it's just a sales brochure. It says the motor is a nominal 36 Volts but doesn't specify stall current. What is the model number of the actuator? Can you provide clear pictures of all of the data labels on the actuator?
Hi,
If you use two LDR to track the position of the sun by finding the brightest bit of sky, you do not need to know where you are on the earth.
In fact on a dull cloudy day the LDR system will still find the brightest part of the sky.
A sundial type protrusion on the PV platform will help you get the angle for your longitude.
Simple...
Tom....
reed switch 48 pulses / inch