Results 1 to 7 of 7

Thread: Help me track the sun. I'm not sure what I'm doing wrong.

  1. #1
    Variable Bitrate
    Join Date
    Aug 2006
    Location
    Central PA
    Posts
    246

    Help me track the sun. I'm not sure what I'm doing wrong.

    My project involves 3 photosensors that I'm trying to use to track the sun. I have multiple issues. First I'll explain how things are setup. I've attached my config file. It will need changed from .txt to .xml. Please have a look. This is a version 3 brain.

    This picture will help the most. See attachment. The three sensor tubes are made of copper, corked on the bottom to keep critters from entering, and have 3 small holes drilled in the top to allow the light in. They are between 6-7" long, and have the sensor coming in the side with the sensor part facing directly up. I get around a value of 10 when in direct sunlight. I've tried numerous positions for these sensors. The image is that shows where they are currently at is just where I left them for the day. I'm pretty sure I need to start from scratch here.

    Issue #1. The sensors are not consistent. I can open the program and the middle sensor will read a value of 8 and then close and open the program a few times and have it show a value of 5. It really screws up my tracking abilities and I'm not sure what is causing this. This is with a clear sky and no random clouds.

    Issue #2. The program simply won't update the values sometimes. If my digital outputs are on, sometimes the program simply will not change the value of my analog inputs resulting in the dish just keeping on moving. It doesn't always do this, but it does it enough to be a real problem.

    Issue #3. (The biggie) I can get the dish to move toward whichever sensor has the highest value, but I can't get it to stop consistently when it's directly facing the sun. The best I got right now is that it will move toward the highest sensor and then where the two sensors are even it will just move back and forth. This is the biggest issue as I'm dead in the water if I can't get it to stop moving when it actually is focused on the sun. I tried to add some logic in to keep it from moving when it gets to the center, but it doesn't work well.

    Any advice would be greatly appreciated.
    Attached Images Attached Images  
    Attached Files Attached Files

  2. #2
    Variable Bitrate
    Join Date
    May 2010
    Location
    Australia
    Posts
    378
    I don't know anything about the fusion brain but your project interests me.
    Is there a reason why you are not using the time of day and a "map" of the suns path across the sky to precisely position the dish at all times? Then this way it doesn't matter how cloudy it is it would always be pointing at the sun and you wouldn't get jerky movements etc..
    I know that most GPS's can tell you when the sun sets and rises so finding the suns path shouldn't be too difficult?

    Sorry if that is too far off track.

  3. #3
    Variable Bitrate
    Join Date
    Aug 2006
    Location
    Central PA
    Posts
    246
    That may be possible, but it'd probably be harder to implement than what I'm doing. Tracking the sun directly also helps me make sure I get the most of the sun no matter if its winter or summer. It'll also be easy for me to add a second axis in the near future not to mention the brain will let me add all kinds of safety features when I get the tracking working properly. Clouds may be an issue at some point, but for random passing clouds I don't think I'll have too much trouble. If it's completely cloudy, my system won't be very useful anyway . I added a link to my signature that has more info on the project.

    Tomorrow I plan on taking the sensors out of their enclosures and just mount them to a flat board and make sure they all read the same. I also believe I've figured out a way to solve the not stopping / jerking issue. I'm doing middle sensor - left sensor is > 2 AND middle sensor - right sensor > 2 means we're pointing at the sun. I'm going to try middle sensor - left sensor is greater than 0 and less than 1 AND middle sensor - right sensor is greater than 0 and less than 1. Or something like that..

    Edit: Actually if the middle sensor is the highest that would accomplish what I want. As long as I can figure out why my sensors aren't consistent this should work actually.
    Last edited by scotty562; 06-18-2011 at 11:31 PM.

  4. #4
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    The photosensors are extremely directional. If they are tilted a bit in the tube, then they will read differently even if pointed at the same thing. For something like this and using the V3 (4 years old now...) then you will need to sample a ground inbetween. So jumper between ground and the input between sensor A and sensor B, as well as ground between sensor B and sensor C.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  5. #5
    Variable Bitrate
    Join Date
    Aug 2006
    Location
    Central PA
    Posts
    246
    Quote Originally Posted by 2k1Toaster View Post
    The photosensors are extremely directional. If they are tilted a bit in the tube, then they will read differently even if pointed at the same thing. For something like this and using the V3 (4 years old now...) then you will need to sample a ground inbetween. So jumper between ground and the input between sensor A and sensor B, as well as ground between sensor B and sensor C.
    I must not quite understand. How do I put a jumper in between input of ground and the input between sensor A and sensor B when the pins are all covered up by the sensors?

    Edit:
    I think I got it. So right now I have my sensors at 0, 1, and 2. You're saying I should have them at 0, 2, and 4? and I should put a jumper between the ground and input of port 1 and 3?

    Edit2:
    Zeroing out 1 and 3 seems to have helped quite a bit. Would it be worth it to zero the rest of the unused ports out?

    Also light was coming up through the cork somehow. I taped the entire bottom half of my copper tube and that also helped significantly. I've noticed that if one sensor goes to 20.05 while the rest are at around .20, one of my other sensors will also start reading 20.05 even though it is not receiving that much sun. What could cause that?
    Last edited by scotty562; 06-19-2011 at 12:25 PM.

  6. #6
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    Quote Originally Posted by scotty562 View Post
    I must not quite understand. How do I put a jumper in between input of ground and the input between sensor A and sensor B when the pins are all covered up by the sensors?

    Edit:
    I think I got it. So right now I have my sensors at 0, 1, and 2. You're saying I should have them at 0, 2, and 4? and I should put a jumper between the ground and input of port 1 and 3?

    Edit2:
    Zeroing out 1 and 3 seems to have helped quite a bit. Would it be worth it to zero the rest of the unused ports out?

    Also light was coming up through the cork somehow. I taped the entire bottom half of my copper tube and that also helped significantly. I've noticed that if one sensor goes to 20.05 while the rest are at around .20, one of my other sensors will also start reading 20.05 even though it is not receiving that much sun. What could cause that?
    Yes you got the zeroing. You should ground the one after as well. So use 0, 2, 4 and ground 1,3,5. It only happens with extremely sensitive measurements. Also, where is the FB in relation to all this? Do you have a PC by the dish, or are you using extremely long wires back somewhere?

    Nothing I know should cause it to report the value of another sensor. But V3 is very old both in firmware and hardware.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  7. #7
    Variable Bitrate
    Join Date
    Aug 2006
    Location
    Central PA
    Posts
    246
    The brain is at the end of the photosensor and one of the extension cables the store sells. The pc is by the dish. I ran electrical cable out for it.

    My actuator failed so it'll be another week until I can get back to this. Things seems to be running much better. I had just started testing too . Oh well, time for upgrades .

Similar Threads

  1. Displaying - Track # - Artist - Album - Track Name??
    By tbird2340 in forum FrodoPlayer
    Replies: 0
    Last Post: 03-05-2005, 01:41 PM
  2. TRACK NUMBERS_ fp dosent allow fractional track notation
    By fly_dutchie in forum FP Bug Reports
    Replies: 2
    Last Post: 11-06-2004, 05:35 PM
  3. TRACK NUMBERS_can't get the track numbers to display properly
    By fly_dutchie in forum FP Bug Reports
    Replies: 1
    Last Post: 11-06-2004, 02:44 AM
  4. track slider?
    By liquid_smoke in forum FrodoPlayer
    Replies: 1
    Last Post: 06-20-2004, 01:09 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •