Green house automation - free design ideas

The first thing that is needed in control systems design is a Control Philosophy.

The hardware is 'how', which occurs much later than 'why', 'what', 'where', 'when' and 'who'.

Green house if you have one then I expect some degree of related knowledge. Idea here is not to teach some one who has not done basics of the green house to plan from zero level, and for that information from others sources need to be obtained.

I want to help those know, what they want to do and only finding hard to get right things in working form.

For example soil moisture and leaf moisture is of concern them one needs proper humidity control. soil moisture sensor and atmospheric humidity sensor with humidifier or water spay system are ideal things. If you have cactus plants then humidifiers are much better than water spray.

You can also use simple controllers or highly programmed computer controlled systems. It is all possible to discuss here.

Your green house may be very large or just table top design. Any thing is OK to discuss here. I want people who do something in their gardens to come up with requirements.

What about CO₂ sensors? Are there any on the market?

Yes, there are CO2 sensors of different types are available. These are optical and electrolytic cell and semiconductor based. One also requires NH3 sensor if there is too much humus ant it comes from composted leaves.

I am planning large green houses in 10 acre or 2.5 hectares area. This is an experimental plan to grow special plant inside the green houses. I will also have one small green house in dry land for cactus. I love cactus.

If I can buy some land in USA then I will like to put up green houses there also. I want my scientific Labs in area where there are more green houses for research. I have all resources for data collection and controls. I will welcome any one coming forward in joint research anywhere who can handle thing in my absence.

I'm intrigued. I just etched a circuit for a timer for misters in my little makeshift greenhouse. I was thinking of expanding my circuit a little to activate the misters not only on time, but when humidity drops or temperature increases to an unsuitable level. I used some circuit diagrams I found online and modified them to my specifications. I would be really curious to see what you have come up with.

Give me draw of your thermistor circuit and I will let you know that can also be used for humidity sensor or not. Honeywell used to make humidity sensor with voltage output and such sensors can work with simple comparator.

You can also take help from those making Cigar Humidor as they use humidity controllers. You can get more ideas there.

www.avallohumidors.com/

Green house design is a great topic and great discipline of work. I was thinking recently that a green house with a properly designed roof should be able to be solar and geothermally heated. The walls would not need to be transparent if the greenhouse were broad and flat. With a very large ground surface under it, the thermal effect of the walls would be minor. Please pardon these thoughts tangential to your topic, but I feel they may be useful these days.

There is no unique design for the green house. Much depends on what you have in green house and how the external climate will affect it. Purpose of having a green house is primary for its design.

In India forest department create those square shape green houses to germinate forest trees. Two to three different types of green houses are planned for such requirement. Initially plants are small and take small space and hence have very congested planting methods, frames to hold plants and to create warm atmosphere suitable for germination free from fungus etc and with controlled humidity and temperature. Each plant is generated in small package that contains nutrients and hush cover for roots. In next stage you need larger green house where more space is required for each plant and also greater irrigation and greater nutrients are required. Rarely third stage is required for plants to be planted in forest. However, some medicinal plants and those will not survive in climate change are moved to third type of green house to remain there forever.

The green house often look like military camps or barracks with large mosquito nets like air ventilated close environment free from insects. Some of them use fiber glass walls and roofs and require lots of air flow and environment control. You can see then in wooden structures and special designs and meant for a purpose.

Now a days unseasonal Mushrooms, Vegetable and flowers are also grown in green houses. I am planning such green houses to grow vegetables and flowers and also to keep cactus plants. I am not planning for medicinal plants or forest tree seed plants.

You can say that green house are not for fun alone but increase your income multiple folds. Price for vegetable in non-season are 10 times than in normal season. You always grow something that is not seasonal as you have environment in your control. You get 10 times money also. It is a million dollar business and you also feel good to use technology and feel like an industrialist who knows his business. A cactus plant hardly takes 1ft space and it may give more than few hundred dollars. Rare plants are priceless. It is only an initial stage in India and it will be the great future for billion people as consumers.

Purpose of thread is to help those have green house or those just are about to put up one. There is nothing to debate who are not having any plan and have no idea of soil, deed or plants. Such people can spend their life in concrete walls with plastic flowers and perfume spray. Unless you are nature lover, you will make no meaning out of a green house or dry wood house.

Right now, my circuit is merely a timer based on a 555. I haven't done any research into thermistors yet. I'm a newby to electronics, but have discovered the great potential in designing my own circuits (or borrowing and modifying others ). My greenhouse at this point is a converted hoophouse I built for my chickens. I'm experimenting with propagating grapevines from green cuttings, hence the need for a greenhouse and misters.

I'm really glad to see other engineering minded individuals also have interest in plants and nature.

I will take a look at the humidor site during my off hours. I hadn't thought of looking a humidor controls. Perhaps you have some thermistor circuits that would be useful.

You can also try to contact Ron at http://cigarsolutions.com/ and he is working with Allen www.avallohumidors.com/ and they have developed this nice humidity and temperature display and humidity controller.

I have an inhouse dripper system for various plants. It works about 90% hands free. However it is not possible to always get the exact amount of water a plant needs. After a month there is either not enough water or too much and the plants are different in their needs. Some are in the sun and use more, etc. I need something to sense how wet the soil is and a shutoff of that particular segment of the system. I'm not a rich kid, just lazy. Thanks

I don't mind lazy people.

Soil moisture is often sensed using conductivity sensor. It requires some idea of the type of soil you have or at least a trial and error short of thing.

To make a soil moisture sensor you need two metal strips or rods and small wooden plant and wires. See in above figure. Connect wires in place of timing capacitor or resistor in an oscillator circuit and you can get frequency change with moisture.

Such sensors you can also find in the market. Simply insert then in soil and use them for irrigation control.

That's doable, thanks. What about electrically operated valves? They seem very expensive $100 ea. 1/4" is all I need. Anyway to make my own?

Sir

Can you provide the pH probe and sensor circuit

Also a detailed knowledge regarding how to make a pH probe

Waiting for your reply.