Arduino Solar Tracker

What is does:
It searches for the brightest light source like the sun.

Step 1 How it works

How it works:
I'd made a sensor of 4 LDRs with sheets between them

The withe stips are the LDRs 

 

When the stick on top is righted to the sun or the brightest point 
the four LDRs get the same amount of light on them.

Example1 when the light is left on top:
right-top, right-down, left-down are in the shadow
and left-top get the most light

Example2 when the light is on top
left and right down are in the shadow and top is in the light


 

Comments

[ashrafzulkifli]

dear Geo Bruce ,
yes i am using arduino duemilanova.
but when i uploading the code, its shows problem to uploading to board .
what is my problems actually ?
need some help here !!!!
pleasee..

Binary sketch size: 3794 bytes (of a 30720 byte maximum)
avrdude: stk500_getsync(): not in sync: resp=0x30
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

[geo bruce]

maybe this can help?
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230381702/all

[HardcastleMcKormick]

Hey Bruce,

I have a continuous rotation Servo Motor Springrc SM-S4303R, and a Servo - Medium Full Rotation (SM-S3317S) (I think springRC) that I'm trying to get working for this same project (a friend is using the S4303R for a different project). I've done a bit of research and it looks like I'll have to add a PWM Input change like you did with Poesis. Would you know exactly what sort of change I'd have to add to the PWM Input to make them move properly? The specs for the S4303R say that 1.5uS is the neutral value for the PWM, so I tried (I'm experimenting with the S4303R while my S3317S comes in the mail) using this same PWM values you suggested to Poesis, but to no avail, and I can't seem to find the PWM values for the S3317S. Help! It's urgent!

[geo bruce]

maybe the comments of:
- AHiggins
- RobertC.
- Member #148301: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1278145608
might help
http://www.sparkfun.com/products/10189

[calsyd123]

Hey Bruce:
I am building the same thing. Would you mind telling me what Arduino version you used for this projects?

[geo bruce]

You can use any arduino board
but i'm using an arduino duemilanove

[ashrafzulkifli]

i need some help here !
i got problem to uploading your souce code into my i/o board .
urgently needs help !! pleaseeee .

[jzpearson]

Great project! Has anyone taken the next steps of mounting it onto something like a 100w pv panel or a solar oven? I bet there would be a lot of people (myself included) that would love to see that project detailed on instructables...

[Poesis]

Hey what's up?! I'm built your project but I'm having trouble with it because it is not pointing to the brightest point. I used everything you specified including the code. The only thing that is different is the type of servo I'm using and the photocell also may be different. Can you please help me?
3-Wire Servo -(http://www.vexrobotics.com/276-2162.html)

[geo bruce]

the servo can only turn 100 degrees instead of 180 degrees I don't think that's a big deal

but the datasheet says:
""PWM Input:1ms - 2ms will give full reverse to full forward, 1.5ms is neutral""
and the servo library default is min 544µS, max 2400µS

so u have to change:
- horizontal.attach(9);
- vertical.attach(10);
to
horizontal.attach(9, 1000, 2000);
vertical.attach(10, 1000, 2000);

try it!

[Poesis]

you are genius!!!! thanks it works alot better now...now how would I have to change the circuit for photocells if you don't mind me asking...

[Poesis]

Yea i know about voltage divider....how about the LDRs can i use a photocell because they are sort of the same thing...

[geo bruce]

Yes, you can.
You just have to change the circuit a little bit

[EffinSwagger]

What are the values for the 'speed' and 'tolerance' potentiometers connected to the arduino? We connected our arduino to the horizontal output of a ECX1070 Electronic Speed Controller, and the vertical output to a Tekin FXR Pro Speed Controller. We got it to run in the correct directions with respect to the photovoltaics along with moving the horizontal gear motor and virticle linear actuator in the correct direction; however it will begin to do its own thing after a few seconds. We believe the output signal going from the arduino to the ESC's are communication in different languages (voltage change out of the arduino vs frequency change to control the ESC's) not being the same.

[geo bruce]

What are the values for the 'speed' and 'tolerance' potentiometers connected to the arduino?
>>They doesn't matter 10K ohm is ok

(voltage change out of the arduino vs frequency change to control the ESC's)
>>The arduino doesn't give a voltage change to control a SERVO

can you give some details of your project and will you send me your code?

thnx

[Poesis]

This is a great project. Alot of great projects can be added to this,FANTASTIC!!! Are those 1k resistors? What about the pots what are their values?

[geo bruce]

Yes it are 1k Ohm resistors
and the value of the potentiometer doesn't matter
because it's just used as an *voltage divider

* http://en.wikipedia.org/wiki/Voltage_divider

[Adam_D]

Nice :) I'm in the UK and our weather is not great...what does your tracker do when the sun is obscured by clouds?

[geo bruce]

It is actually looking for the brightest points, so when the sun is obscured it search an other one.
It only adjust its position if there is an brighter source of light

[trobinson12]

What would be cool is if you were able to use bigger servos and mount solar panels to it, and use that to power it, so It would constantly get power as long as sun hit the panels, and what better then panels that track the sun. Make it big enough and you could power something all day long.

[frankcalzia]

I have built this circuit three times. The horizontal motor moves slightly, the vertical, none at all. Values from the sensors average around 500. "dvert" = 86, "dhoriz" = -25, "dtime" = 50, "tol" = 150. Any idea what I am doing wrong? This is the perfect solution if only I can solve the problem.

[geo bruce]

yeah i see the problem
you said:
" "dvert" = 86, "dhoriz" = -25,"
it only changes the position if one of the values is bigger than the
tol = 150
if you make tol smaller it should be more sensitive

[ATTILAtheHUNgry]

Super awesome. Just use a sensor like this to auto-align solar powered objects like solar ovens and the like. You get my vote.

[geo bruce]

THNX

[drozzle]

Very cool, one of the few space related projects in the space challenge :D

[geo bruce]

^^ =D

[philic]

Great idea and exactly the type of thing I have been searching for. Is there any reason this couldn't be done with 3 sensors arranged in a 3rds formation as opposed to the 4 in quarters like you have done? I just trying to think how to reduce the BOM. Cheers.

[geo bruce]

Yeah it must be possible,
I should go for A

[shahzade]

Dude!!
I'm impressed by the design of the sensor. Did you come up with that by yourself or did u see that somewhere else before?

Great project, definitely on my todo list!
THX Shah

[geo bruce]

I saw a long time ago on tv a lightsensor with 4 LDR's but I improved the idea

thnx

[rocketman221]

Cool. It just needs some bigger servos so it can move a solar panel around.

[1tri2god]

this is awesome! What kind of LDR's did you use (so I can look 'em up and buy them)?

[geo bruce]

It doesn't matter what LDR's you use
the ldr I used:
dark > 400kohm
light 100ohm - 20kohm

and I'd set it in series with an 1K resistor

[1tri2god]

thanks!

[geo bruce]

you're welcome!

[piratus]

that s cool !! but where can i find micro serve ?§ thanks

[geo bruce]

you can find them really cheap on ebay

look here:
http://shop.ebay.com/i.html?_nkw=4+x+servo+9g&_sacat=0&_sop=15&_odkw=4+x+servo&_osacat=0&_trksid=p3286.c0.m270.l1313

4 x servo = 10$ shipping included
http://cgi.ebay.com/4-X-Micro-9g-Mini-Servo-Futaba-Hitec-HS-55-GWS-walkera-/160601107472?pt=Radio_Control_Parts_Accessories&hash=item2564926c10#ht_2542wt_1139

or you can find them on dx
http://s.dealextreme.com/search/servo

no problem

[rimar2000]

This is a VIP: Very Important Project.

I was working in an equatorially mounted solar cooker. All is right, except it lacks a solar tracker!

[Kiteman]

This is really very cool - an über-headbot.

We really need more details on how you mounted the actual mechanical parts, though.

[geo bruce]

I'd just created a new step with a lot of pic's with the construction
(just hot glue)