Shop OBEX P1 Docs P2 Docs Learn Events
Automated Hydroponics — Parallax Forums

Automated Hydroponics

zed of zardozzed of zardoz Posts: 20
edited 2011-11-14 02:52 in BASIC Stamp
Hey, folks
I have had the basic stamp kit for a while now and now I want to use it to automate my hydroponic setup. Basically I want it to dump the old solution, mix the new solution, and wait the specified 2 weeks between looping the program.

I have this hydro setup.

The attached file is the preliminary breakdown of the steps.

Update 12-20-10:Below is a crude plan with major parts included.
major components.JPG
xls
xls
hydrosched.xls
19K
major components.JPG
624 x 921 - 39K

Comments

  • FranklinFranklin Posts: 4,747
    edited 2010-12-19 12:54
    Sounds like a great project. Keep us posted as you progress.
  • zed of zardozzed of zardoz Posts: 20
    edited 2010-12-20 07:06
    While I'm sourcing parts let me put this question up for you guys. If you read the steps in the attached .xls file, you would see that there is a 2 week wait before the program loops. This is because the proportion of fertilizer to water drops below what is beneficial for the plants at the accelerated absorption rate induced by the system. Besides coding it to wait for 1209600000 m/s, is there another way to write it?

    thanks
  • Mike GreenMike Green Posts: 23,101
    edited 2010-12-20 08:34
    Because the Stamps use 16 bit numbers and the longest delay is on the order of a minute (PAUSE 60000), you have to use repeated delays to get really long periods like 2 weeks. You'd have the 1 minute delay in a loop that goes 20160 times to give a 2 week delay (60 * 24 * 14). Another option would be to use an external real-time-clock with a backup battery or super-capacitor like the DS1302. This has the advantage of protecting the timing from brief electrical outages. You could also use a backup battery for the Stamp, but it uses more power than a DS1302. You could use the SLEEP statement instead of the PAUSE statement to reduce Stamp power consumption during the long waiting period, but you have to be careful about how your output pins are used. See the description of the SLEEP statement for details.
  • zed of zardozzed of zardoz Posts: 20
    edited 2010-12-20 09:00
    So what you mean is have it perform the operation on a specified date in 2 week intervals? Or have the basic board run the program every 14th time the clock hits midnight (or whatever time is chosen)?

    thanks mike
    zed
  • zed of zardozzed of zardoz Posts: 20
    edited 2010-12-24 08:45
    Mike Green wrote: »
    You could use the SLEEP statement instead of the PAUSE statement to reduce Stamp power consumption during the long waiting period, but you have to be careful about how your output pins are used. See the description of the SLEEP statement for details.

    WHere in the basic stamp book is SLEEP? I cant find it even searching the pdf version.

    thanks
  • FranklinFranklin Posts: 4,747
    edited 2010-12-24 09:13
    Look in the stamp editor help file.
  • walken.chriswalken.chris Posts: 3
    edited 2011-10-19 01:08
    I have gotten a lot of help from this forum related to hydroponics.
    Thanks for Sharing with us.
  • GadgetmanGadgetman Posts: 2,436
    edited 2011-10-19 01:34
    Nice setup. Looks way more pro than my own system...
    http://our.windowfarms.org/?p=3003

    Anyway, I would recoommend a real-time clock, and if you can get hold of a hackable PPm meter(Parts Per Million) that you can use to measure the nutrients in the water with, that would be good.
    Just swapping the liquids out after two weeks is not good.
    What you need to do is to measure PPM every day and keep track of how it decreases. When it stops decreasing it means the plants have taken up all the nutrients they can use of that mix.
    That is the time to change the liquids. (With me that can be as often av weekly)
  • zed of zardozzed of zardoz Posts: 20
    edited 2011-10-19 06:51
    gadgetman,
    I ger what you are saying about the PPm meter but isnt there a point below zero ppm where the plant is starving for nutrients? Or is there a point at which there just isnt enough nutrients to matter?
  • GadgetmanGadgetman Posts: 2,436
    edited 2011-10-19 07:55
    Nope, there's no 'zero' point.

    The problem with nutrients is that the plants never use 'everything' so there will always be something left in the water, so it's impossible to see when it needs to be changed.
    So we monitor how quickly the PPM measure drops.
    (Actually, it measures the electrical conductivity of the water, so it should be possible to bodge together something)
    When the daily measurements show that there hasn't been a 'significant' change of the number of particles in the water, we know that the plants have used what they can of them.

    And yes, there's a point at which the plants will starve, but this depends a lot on your setup, and of course how quickly you spot the depletion of the nutrients. With a test every day or so, the plants won't starve for long enough to cause problems. And besides, if you keep a log, you will be able to predict it better and can do the replacement operation at the time when the nutrients hit that point.

    Something else you also want to consider is to measure PH and correct problems with that before they result in big trouble.

    Here's a PPm tester for $11.50 (shipping included)
    http://www.dealextreme.com/p/0-7-lcd-tds-water-tester-2-x-lr44-80940
    It seems to work OK for me. Haven't tried to hack one to see if it can be connected to a BS2, though.
  • zed of zardozzed of zardoz Posts: 20
    edited 2011-10-19 08:18
    Being as id be measuring the ppm wouldn't it be better to simply keep the water level correct and add more nutrients to top off the correct nutrient level one a week or whenever necessary? Come to think of it I wouldn't even need to change the water. Just top off the nutrients.
  • GadgetmanGadgetman Posts: 2,436
    edited 2011-10-19 23:26
    PH is about the acidity, not the level(volume) of water.
    Drop too low or too high, and plants may die.
    (Some plants prefer a higher/lower PH than others, though)

    Topping up means that you don't get rid of the 'remains' of the old nutrients. After a while you end up with so much waste in the system that it may clog up filters or pumps.
    (Also, it'll cause havoc with the PH as old nutrients starts breaking down. )

    Unless you have some very expensive gear to measure what is or isn't still available in the liquid, how will you know what to add and when?
  • RDL2004RDL2004 Posts: 2,554
    edited 2011-10-20 06:06
    Using chips known as "frequency dividers" along with a relatively slow oscillator, it is possible to generate square waves with periods that are measured in hours. The Basic Stamp can periodically sample these and accurately determine intervals of many days. Or you could go to the trouble (and expense) of using a "Real Time Clock" chip.
  • zed of zardozzed of zardoz Posts: 20
    edited 2011-10-25 21:00
    Gadgetman: good point i didnt think of the decaying nutrients.
  • sonyagilmansonyagilman Posts: 1
    edited 2011-11-01 03:09
    Thanks for sharing your experience I have a nice idea i know the store in that store you can get a better seeds in a very cheap price they also tell you about effective production of hydroponic pot,the store name is coasthydroponics and you can also visit online coasthydroponics.com
  • walken.chriswalken.chris Posts: 3
    edited 2011-11-14 02:52
    this is great place to discuss here regarding hydroponic
Sign In or Register to comment.