Codyhtml Posted March 27, 2006 Report Share Posted March 27, 2006 Hi i've been inactive for a while but I have a questionI would like to use the plants wattering watcher (1 or 2) to monitor the moisture level in a compost pile.but I need a little help modifying it idealy I would like to have a bar graph display (out of LEDS) Rather than a blinking led. Battery life shoulden't be a problem I have an old solar yard light that I would like to incorperate in as the power source it has two rechargable ni-cad batterys 550mAh at 1.2 V Also as simple as possible would be nice if there is any was to simplify it that would be nice thanksps. I tryed to make this post easy to read :DEDIT:I just did some tests on the solar panel and i got this Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 28, 2006 Report Share Posted March 28, 2006 Hi Cody,The Plants Watering Watcher-2 project can be modified easily to produce a DC output voltage for driving an LM3915 bar-graph LED display.Your 2.4V battery is a problem for the LM3915 since it needs a min of about 3.0V.If many LEDs are lighted then they will quickly discharge the battery. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 28, 2006 Author Report Share Posted March 28, 2006 ok great my solar panel gives about 4v in bright sun could I modify the the charging circuit (witch i might have to to disable the off at day and the on at night anyway) to use 3 double a cells or if I need to I could probably use two lights so I have 2 panels and 4 batteries what would be the easyest and best?and what about two sets of probes how easy/hard would that be?I just got another thought what if i ran the bargraph display off the solar panel that would give it 3.5-4V and it would not be on at night which is not needed Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 28, 2006 Author Report Share Posted March 28, 2006 ok well I did my home work and this is what I got the ares in red I wanted to bring attention to because i figured i might have made a mistake thereEDIT: I got thinking do i need to calibrate this and if i do how? Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 28, 2006 Report Share Posted March 28, 2006 Hi Cody,In the Plants Watering Watcher-2 circuit, the IC's pin 8 is oscillating at about 2 Hz, and pin 11 is Pulse-Width-Modulated at about 3kHz.I have made pin 11 feed an inverter which is integrated with an RC pair into a DC voltage which represents the dryness between the probes.Then I setup the reference voltage of the LM3915 as a 3.33V voltage regulator for the 74HC132. The circuit must be powered with 4 AA Ni-Cads or Ni-MH cells for about 5V. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 28, 2006 Author Report Share Posted March 28, 2006 Ok thatks that is awsome thats the basics of what i neednow how can i use two solar panels to charge 4 ni-cads such as what the solar yard lights doand can i have two or even three sets of probes to get a more acurate reading from the whole compost pile not just one spot?thatks for your help so faroh and in my schematic i left it a moving dot displayon purpose i decided that is all i need that way i save battery life and reduce power consumption Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 28, 2006 Report Share Posted March 28, 2006 Hi Cody,I guess that my circuit will work, I didn't try it.You can disconnect pin 9 of the LM3915 for a DOT current-saving mode. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 28, 2006 Author Report Share Posted March 28, 2006 Ok i'm not sure if i know how to build a simple ni-cad charger from my solar panel can you help me with that?How do i make several sets of probes do i need to do anything special? Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 29, 2006 Report Share Posted March 29, 2006 Since your solar cells can output a max current of only 60mA and your Ni-Cads need 55mA for 14 hours, the Ni-Cads will never be fully charged and the charger is only 2 solar cells in series and in series with a diode. Any diode will be fine.I don't know if a single circuit can have multiple probes in parallel. Maybe each pair of probes needs its own circuit. My probes for indoor plants soil are tinned thick copper wire about 55mm long and spaced about 18mm. For compost maybe they should be longer to make good contact. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 29, 2006 Author Report Share Posted March 29, 2006 Since your solar cells can output a max current of only 60mA and your Ni-Cads need 55mA for 14 hours, the Ni-Cads will never be fully charged and the charger is only 2 solar cells in series and in series with a diode. Any diode will be fine.that should be fine the main purpose of the solar cells is/was to extend the battery life. I can charge the ni-cads in a charger and the solar panels should keep them topped off for a while. Essentially making up for the extra draw of the bargraph/moving dot display.I guess i can experiment with the probes i don't see what would be a problem thoughFor the charger just any general purpose diode rightThanks once again for your help if i get it all worked out mabe this could be another project since this is a fairly large mod :DEDIT: one more question the 2.5k resistor that I see in the circuit (on the LM3915) is that a POT if it is what kind linear, Logarithmic and what pot from here http://www.futurlec.com/Potentiometers.shtml would be the best to use? Quote Link to comment Share on other sites More sharing options...
Staigen Posted March 29, 2006 Report Share Posted March 29, 2006 HiWhat kind of gardeners are you two, dont ever put any kind of current into acompost, the compost will die! The worms shy electricity to every extent! Andthe bacterial culture dont like it, and go to rest, and will die soon.//Staigen Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 29, 2006 Report Share Posted March 29, 2006 Hi Cody,Use a 1N400x rectifier diode for the charger.Since Futurlec doesn't stock 2.5k trimpots, use a TRIM2K in series with a 510 ohm resistor to ground.Hi Staigen,My plants like the very small AC current from my circuits. Maybe the current kills the bad things in the soil. Surely the current is only in a very small area between the probes and most of a compost pile won't be affected. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted March 31, 2006 Author Report Share Posted March 31, 2006 so i need to find out wil it ruin my compost pile and is there any way to keep it from ruining my compost pile (putting it in the corner something?) Quote Link to comment Share on other sites More sharing options...
Staigen Posted March 31, 2006 Report Share Posted March 31, 2006 HiWell, i dont know how i should put it, i'm not so good in the enlish language ;DWhen i was young(10-15years old, about) we had an angry gardener livinghere, and when we where there, trying to steal his vegetables and fruit, hewas hunting us, and to revenge we put a 1.5V battery cell with wires to hiscompost. The wires was buried in the soil at each end, and the battery washidden behind the compost, digged down a little, and the compost did notwork. This was done in the spring, and in the spring the next year he foundthe battery and reported it to the police, but they didn't cought us. This "trick"was told to us by one of the fathers of my friends. Also, when we was goingfishing, and needed worms for the hook, we put 220V into the ground, and allworms around immediately turned up above ground, several meters around.As you see, i havent always been a nice guy 8) :P ;D//Staigen Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted April 1, 2006 Author Report Share Posted April 1, 2006 I got an idea what if I took a PVC pipe and put it in the corner of the compost pile and filled it with the same material as the other compost and put the probes into that. PVC is a great insulator and that might even help if any current went out of the bottom of the pipe and into the normal soil mabe it would make the worms want to go into the compost and stay there. I don't Know but what do you think about that idea. The pipe should dry out at about the same rate as the rest of the pile woulden't you think? Quote Link to comment Share on other sites More sharing options...
audioguru Posted April 1, 2006 Report Share Posted April 1, 2006 Make two compost piles. One with a circuit and the other without. Then see the results and the extent of the current. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted April 1, 2006 Author Report Share Posted April 1, 2006 good idea thanks Quote Link to comment Share on other sites More sharing options...
MP Posted April 1, 2006 Report Share Posted April 1, 2006 No disrespect, staigen. I am not an expert in compost, but as I understand it, the reason a flashlight type battery will ruin compost is because of the heavy metals. Not a dc charge. A nicad or flashlight type battery will have enough heavy metals to ruin a fairly good sized compost pile. This explanation makes more sense to me than the dc charge effecting worms. Otherwise, if it were due to the dc charge, the battery would soon go dead and the compost process would get on it's way again.I certainly do agree with the mains current making the worms come out of the ground. This is how we would get the worms to go fishing when I was a kid. Got a good trickle once on wet ground, though, so I quit doing it.MP Quote Link to comment Share on other sites More sharing options...
Staigen Posted April 1, 2006 Report Share Posted April 1, 2006 The battery was not in the compost, it was outside, behind a wood wall.And the worms comes up fast if you put 220V in the soil. ;D ;D//Staigen Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted April 5, 2006 Author Report Share Posted April 5, 2006 Otherwise, if it were due to the dc charge, the battery would soon go dead and the compost process would get on it's way again.MPI do have to agree but for this year i'll make a second smaller compost pile and see if i can see a difference in them Quote Link to comment Share on other sites More sharing options...
audioguru Posted April 6, 2006 Report Share Posted April 6, 2006 The project uses a very low AC current between the probes. Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted April 10, 2006 Author Report Share Posted April 10, 2006 Ok I built this project Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted April 11, 2006 Report Share Posted April 11, 2006 Hello Back when I used to go fishing, we'd got are worms by using a AC probe. What we would do is take the hot side of a power cord and tape it to a insulated screw driver, tap off the ground side, Plug it in then stick the screw driver into the ground. With in seconds the worms would pop up. The problem is that they would not live very long after that. gogo Quote Link to comment Share on other sites More sharing options...
audioguru Posted April 11, 2006 Report Share Posted April 11, 2006 Ok I built this project Quote Link to comment Share on other sites More sharing options...
Codyhtml Posted April 12, 2006 Author Report Share Posted April 12, 2006 Ok Hi i guess you forgot that you helped me modify this and i don't have a led i have a led bargraph display lolmy batterys are meashring a little over 5von pin 6 i get1.3V on pin 3 i get1.6V on pin 8 i get .64 V on pin 11 i get 2.3VMy ics are i'm guessing you want all of it so here it is poo52ADMM774HC132NMM774HC132NTHAT IS EXACTLY HOW IT IS ON MY FIRST ic (YES I KNOW THERE IS A REPEAT ITS THERE TOO OOPS HAD CAPS LOCK ON LOL)NEXTJB536RALM3915-1 That is how my other ic looks exactly (except for a little logo i can't typeps i don't feel any wormth on the ics if that helps Quote Link to comment Share on other sites More sharing options...
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