Irrigation controller
Bullwinkle
Posts: 101
While the total project is not completed yet. I feel I have reached a major milestone in completing, and fabricating the output boaord for my 6 station irrigation controller. This is the first PCB I have ever made, and I am very happy with how turned out. Quiet a nerve wracking process, but the end product looks good ( at least - in my opinion ) for a home job.
The board will control 6 24 vac garden solenoids, or indeed, any other 24 vac application you have in mind. ( Christmas lights? ) It accepts 6 digital inputs the can be connected directly to the Basic Stamp IO pins or to a shift out register.
I have attached the schematic and circuit board layout, in Eagle Lite format, togther with a few photos of the finished board. I hope someone else can fnd it useful.
The next stage of the project will be fabrication of the logic board including the moisture probe. The stamp will sit on this board, with the RTC, shift out register and LCD connector. The final stage will be the power supply module and housing construction. At the current rate of progress I expect completion by about 2020.
Oh well ... it's just a hobby.
Enjoy.
Steve
The board will control 6 24 vac garden solenoids, or indeed, any other 24 vac application you have in mind. ( Christmas lights? ) It accepts 6 digital inputs the can be connected directly to the Basic Stamp IO pins or to a shift out register.
I have attached the schematic and circuit board layout, in Eagle Lite format, togther with a few photos of the finished board. I hope someone else can fnd it useful.
The next stage of the project will be fabrication of the logic board including the moisture probe. The stamp will sit on this board, with the RTC, shift out register and LCD connector. The final stage will be the power supply module and housing construction. At the current rate of progress I expect completion by about 2020.
Oh well ... it's just a hobby.Enjoy.
Steve
Comments
·I am working on something·like this
····················· ·
I will·have the led see·if it is day light not to·water at night
I will have the·moisture probe see if the yard need to be watered
I will have a button that will start the watering override the auto setting for two hours then go
back to auto·
Which ever come frist
I will have the·moisture probe turn off the water when wet and dose need any more water
I will have the timer turn off the water OFF after TWO hours
I will have led count the days before coming back on
The counter will count 7 days and start over
I·working on the timer routine i have not finsh this yet
The way i am thing about do this is have·count the days by the led the day light so i do not have to
set the clock for day light saving or have to set·ON or OFF Times
This could change as i write the routine
Please let me know how you·fabricate·the moisture probe
I have not work this out yet
I can help you out for a case for your project here is the web page
http://www.kele.com/olcat/E13/PS-SER.PDF
If you want to get this case please PM me
I will give you info on the price on what size case·you want to get and i can give some photo of them
Sam
Post Edited (sam_sam_sam) : 10/28/2006 2:22:21 AM GMT
I like this project
I am working on something like this
I will have the led see if it is day light not to water at night
I will have the moisture probe see if the yard need to be watered
back to auto
<FONT color=red>
<FONT color=red>I will have the timer turn off the water OFF after TWO hours
I will have led count the days before coming back on
The counter will count 7 days and start over
<FONT color=blue>The way i am thing about do this is have count the days by the led the day light so i do not have to
<FONT color=#0000ff>
<FONT color=#0000ff>This could change as i write the routine
Please let me know how you fabricate the moisture probe
I have not work this out yet
I can help you out for a case for your project here is the web page
http://www.kele.com/olcat/E13/PS-SER.PDF
If you want to get this case please PM me
I will give you info on the price on what size case you want to get and i can give some photo of them
Sam
We have a 5 level water restriction system here. We are only ever allowed to water at night, to save water. Currently we are on Stage 1, but moving to Stage 2 next week. I expect we will get to Stage 3 this summer as our dams are now at less than 50% of capacity and we've had virtually no rain for over 2 months!
I am using a Real Time Clock chip and a LCD display so that my program can know the time and date, and calculate accurately when it should come on and for exactly how long. I am using the DS1302 RTC and the 16x2 backlit serial LCD. The logic board isn't finalised yet. I will post it here when I have fabricated it.
Your 2 hour watering time sounds a bit excessive. But I guess it depends of what you are running. Our lawn sprinklers typically only run for 15 minutes per zone, every 2 days even in hot weather. The garden drippers are much slower, so I run them for an hour. But when the moisture probe is installed the system will calculate how long it needs to be on based on how dry the soil is. This will take a while to calibrate, but it's easy enough to do with the Stamp. The idea is to measure the electrical resistance of the soil, this will be inversely proportional to the moisture content. Then I need to work out the "ideal" moisure level. The software then simply subtracts the measured moisture level from the this ideal value to arrive at a number which is directly proportional to how long I should water for. I then need to multiply this by a number calculated for each zone to finally arrive at the run time for each zone.
My moisture probe is simply two pieces of steer rod about 6 inches long connected to the Stamp logic board by a cable. The probe will be placed in a "representative location" in the open, just at the base of the roots of the lawn. I will wire a 0.1 uF capacitor between the wires leaching the logic board from the probe. One probe wire will connect directly to an IO pin on the Stamp, the other to GND. To measure soil resistance I output a "1" signal to the IO pin and wait a few milliseconds to properly charge up the capacitor. Then using the RCTIME command, time how long it takes the capacitor to discharge through the soil. This time will be inversely proportional to how wet the soil is. I have tested this idea in a flower pot, and it works very nicely.
My logic board will have 3 press-buttons also. These will allow for setting the RTC and water restriction stage. And for initiating a manual watering of any particular zone, or cancelling the current watering cycle. Other than that the system will be fully automatic. Once calibrated it will only water just enough of offset evaporation since the last watering cycle. So I can leave it active all year long and it will only water as it needs to, without any waste and without fear of falling foul of the "Water Police" - which can cost you a hefty fine these days.
Thanks for the info on the cases. I am not ready yet to package it up "as a finished product" yet. I have the controller board done, but I need to do the logic board for BS2, LCD and the RTC with battery backup, and the power supply before I can even consider housing it. I have just ordered a BS2e from Parallax, as I have "hit the wall" with the 2KB memory limit on the BS2. All this logic takes lots of lines of code.
If you need help with the moisture probe, send me a PM. It's pretty easy with the Stamps RCTIME command, two bits of metal and a capacitor.
Steve
New sod/grass should be watered 2x a day for ~20minutes.
I'll be interested to see how your moisture sensor works. I suspect you might have some issues with oxidation/corrosion. You say you are using "steer rod" is this steel?
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Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
Steer ... that's finger-fumble for Steel.
I'm actually using 2 old steel garden spray supports, these things already have a healthy coating of rust on then from being in the garden for over 8 years.
And they're cheap.
They worked well enough in my indoor flower top test. The only unknown at this stage is whether adding 10+ metres of cable between the Stamp and the probe will alter the resistance. But I guess that shouldn't matter too much, since I will need to calibrate the software so that it knows the RCTIME value for the "ideal" moisture level to aim for.
Steve
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Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
Please check your PM·I send you a PM
Thanks·for the ·
·Sam