Wednesday, 27 August 2014

Greenhouse/Polyhouses - Developing micro-climate for farmers.

Micro-climate existence in Greenhouse/Poly-house.
When i was young, in school i read about Greenhouse "Greenhouse are used to trap the sun-light energy and provide warmth to grow certain specific plants in cold regions" and now when i am working with Yuktix Technologies, things are getting more clear to me. 

Yuktix is providing precision agriculture solutions, intelligent climate control solutions to develop specific micro-climate inside a greenhouse/poly-house. Along with this we are providing real time monitoring for greenhouse and poly-house. Well i will explain further about the solution which we at Yuktix provide, but before that i would like to discuss the benefits of  a greenhouse/poly-house for a farmer or a common man and this is getting my personal attraction. 

So when we say what exactly is greenhouse/poly-house? I would like to first describe both of them and then i will differentiate them. 

Greenhouse : A greenhouse is a building or complex where plants are grown.A greenhouse is a structural building with different types of covering materials, such as a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming visible sunshine is absorbed inside the structure. Air warmed by the heat from warmed interior surfaces is retained in the building by the roof and wall; the air that is warmed near the ground is prevented from rising indefinitely and flowing away. This is not the same mechanism as the "greenhouse effect".

Greenhouse where we are installing our-climate control solution


Poly-house : Poly-house is a greenhouse with plastic based walls. 
Poly-house 

So the basic difference between the both is cost of investment, their sustainability in extreme weather and their effectiveness. Generally developing a poly-house is much more cheap in comparison to developing a glass or hard plastic based poly-house. While the cons of poly-house is that it cannot withstand extreme weather for a longer period of time. But in all poly-houses are very much reliable and people generally prefer to go with poly-house option. 

As per a forum capital investment in developing a poly-house of dimension 1000 sq. meter poly-house @ Rs 450 /sq meter will be 4,50,000 and Indian government at present is providing huge amount of subsidy to those people who want to develop poly-house but that differ from state to state just like Kerla government is providing 75% subsidy for hi-tech agriculture farming in which central government is providing 50 % and rest 25% is provided by state government. For more information on the same, have a look at this link and this discussion on the farmers forum. So now when we talk about hi-tech agriculture and farming, what does it means? Well this much be quite clear to the people around us and we might have even heard about different existing technologies in the market like SMS based irrigation controlled system, miss-call based motor control system etc, etc. Now let me introduce Yuktix in the same field. 

When we talk about hi-tech agriculture farming and considering that we are in India, we have to deal with lot of issues like people don't give a shit about safety features, they don't want real time monitoring and Indian farmers are still very much behind in the using technology for farming. So we at Yuktix are providing precision agriculture solutions  to the farmers using our own developed AWS(Air weather station). We also provide intelligent climate control solutions and real time monitoring systems for polyhouse/greenhouse. As this blog post is specifically on maintaining micro-climate for greenhouse, so emphasis will be more on intelligent solutions for greenhouse/poly-house. 

Intelligent Climate control solutions for Greenhouse/Poly-house-By Yuktix Technologies. 
So when we say intelligent system, we really mean it. It is not timer based(although we also provide timer option in our solutions) solution but is is embedded system running a algorithm in its CPU which adjust the internal environment of the greenhouse/poly-house. Just like it adjust the moisture of the chamber depending upon if it rains or not, or if it is night or day and similarly, it adjust the temperature of the chamber depending on the season and time of the day, so that you need not to worry always about the control of the greenhouse/poly-house internal environment. Along with that , you can always monitor the real time variables of your greenhouse/poly-house either on our web-based application or on our customized Android app/I-phone app or if you don't have a smart-phone, just send a message and you will get real time variables of your greenhouse/poly-house. Along with this you can always adjust the range of the temperature, humidity or lux by simply accessing your account and changing certain parameters. Isn't that sound cool, but its really possible now. With the new emerging technologies like IOT(Internet of Things) and M2M(Machine to Machine) communication and increasing use of GPRS based technologies, it is relativily easy now to monitor and control things from any where in the world.  So below is the list of some of the discrete and effective solutions that come under the category of intelligent climate control solutions for greenhouse/poly-house. 
  1. Yuktix Intelligent Data-logger - For real time monitoring and local data-accumulation. 
  2. Yuktix Intelligent humidity control system - For controlling and maintaining the humidity of the chamber inside greenhouse/polyhouse.
  3. Yuktix Intelligent temperature control system - For controlling and maintaining temperature of chamber inside greenhouse/polyhouse.  
  4. Yuktix intelligent lux control system - For controlling and maintaining lux or amount of light coming inside greenhouse/poly-house.

Yuktix Intelligent Data-logger 
Yuktix data-logger can measure different variables via different channels like I2C, UART, Analog , store them locally for future and send them to our cloud where they are again stored and displayed in the respective accounts which a user can easily access via website or via smart-phone application. 

Yuktix DL

Yuktix working DL in someone greenhouse

Android app showing real time data. Same is also available on web-app.

Yuktix Intelligent humidity control system 
Citing a example from one of the greenhouse in Bangalore who are growing chrysanthemum flower, they require to maintain a humidity of 90% in their poly-house chamber which they were earlier doing with the help of manual labour. Everytime after some period someone was require to turn ON and OFF a motor which in turn will control fogger. What we had done is we had replace the dependency of  manual labor to turn ON or OFF motor and operate it with our intelligent humidity control system which take care of everything including power consumption. Along with that if  you want to monitor it on web-app or android app, you can do that also. Below are some of the pics which explain automatic control of the humidity. 
Humidity control process in progress.

Humidity readings


Yuktix Intelligent Temperature control system 
Again citing a example. Rose flower cultivation require maintaining temperature of the chamber. This was again being controlled by Yuktix intelligent temperature control system which turn ON or OFF blowers which in turn will control the temperature of the chamber. Our system also take care of the timings of the day, outside temperature and other factors like power consumption.

Yuktix Intelligent lux control system 
Citing the example of the growth of chrysanthemum  flower, in their later stages when they are about to come up with the flowers and for export market, size of the chrysanthemum flower need to qualify some specific criteria, they need light for limited hours over a day span. So we controlled this requirement of theirs with the help of our very precise lux measurement system and yuktix intelligent lux control system which in turn will control the curtain system and thus amount of light.
chrysanthemum chamber with automatic lux control system
So with the help of all the above stated solutions from Yuktix, a greenhouse/poly-house owner can control the micro-climate required in the greenhouse/poly-house to grow different type of flowers, vegetables, fruits, plants, monitor their chambers internal environment from any where in the world any time and thus in case of emergency can call for manual help in his/her greenhouse/poly-house. I request the readers to please come-up with any type of questions with respect to any above stated technology and we will be happy to resolve your query or problem. 

You can drop mail at shailendra@yuktix.com or can directly call +91-9910908382. Also kindly visit our facebook page for latest updates or subscribe to our blog via email.

Happy Farming.......   


Tuesday, 26 August 2014

Testing 3 phase motor with single phase supply

Testing 3 Phase motor with single phase supply
When we are in office job or in corporate job, our life is full of comfort, weekends, holidays, CL, Medical leaves, others perks, office vehicle etc etc and life seems to be cool and happening. Things start changing when we start thinking and doing something of our own or you can say that when you want to be a entrepreneur. The basic difference between the both is that while being in corporate you are running a engine whom some one else had build and in later case, you are trying to build your engine by yourself and in that case you have to take care of everything, everything means everything starting from idea stage, development stage and when you are in embedded domain, you might even have to do plumbing, painting, electric work etc just like my boss in Yuktix has did and no wonder many other's have done, because there is no other way in the early stage of a start-up. 

So the basic aim behind writing down this post was to share the experience of testing a 3 phase motor panel with single phase supply and playing with daemons as stated in this facebook post. So first of all i would like to give some basic information with respect to the single phase supply, 3 phase supply, single phase motor and 3-phase motor


So i hope that above information and links might have helped you to have some basic knowledge of stated topics. When we talk about embedded, we generally deal in range of 0V to 5V and if required maximum of 12 volts for supply. We never deal with 220V 50 Hz single phase supply or 3-phase supply. So when it came to test the motor panel that we are using to drive a 3-Hp  motor, we raise our hands in the air and gave up. At this time, our all time embedded hero, Ashok sir, came into scene and share the way to test the motor panel with single phase supply. The idea was simple. Short the 3 phases of 3-phase supply using MCB, get a single wire out of it, get a neutral line from the panel, plug them into the AC single phase supply, prepare s set-up of 3 bulbs and we are done. wow...for some one, it might be gone over the head, just like happened with me for the first time, but with time, i got that. I will explain each step with pictures and that will make everything clear. 

Step 1 : MCB which we were using was 3-phase 16 Amp MCB. So we need to short all the 3 ports of MCB and get a single wire out from the last port as shown in below figure. Also from the panel, we can take out neutral from the panel(every motor panel will have that - named as terminal block ).
MCB with shorted ports and connection to mains
Step-2 : OLR(over load relay). Every motor panel will have thermal overload relay, out of which 3 wires will be coming out(keeping in mind that we are dealing with 3-phase induction motor). So in order to test that, we have 3 options with us.
  1. Test with Multimeter 
  2. Test with 3 Red, Yellow and Blue Bulbs
  3. Test with the real 3 -phase motor (If you have...)
Test with Bulbs : Connect the wires as per shown in below pictures with bulbs and neutral and if everything is fine in your motor panel, after giving single phase supply, you 3 bulbs i.e Red, Yellow and Blue will glow showing that you are getting 3 phase output from single phase supply. 
Connecting 3 bulbs to 3-phase output

Test with Multimeter : You can test the voltage of 3 R,Y, B terminal blocks coming out of OLR and you will see voltage readings of 240V on these terminal blocks.

Test with 3-phase motor : You can also test the same setting with a real 3-phase motor as we did with 5-hp motor(god, i hadn't even dreamed of running that big monstrous motor. )
3-HP 3-phase motor we are running in our automatic humidifier 
5 HP 3-phase motor testing
So this was all what we had done for testing our panel with  a 3-Hp/5-Hp motor. And below is the picture of chamber with automatic humidifier and real time readings on the data-logger and on our cloud app which greenhouse/polyhouse owner can access. 
Yuktix Data-logger displaying chambers readings
Yuktix Cloud app showing real time data(Its cumulative average, we send to server periodically)

Yuktix DL with different readings



Humidity Chamber with Automatic humidifier running



Monday, 25 August 2014

Lab test and real time project side tests

Lab/office tests and real time project site tests - the basic difference
It was i think our 5th trip to the greenhouse where we are implementing our greenhouse/polyhouse intelligent systems for internal climate control as well as real time monitoring of the variables. We have been testing our systems religiously in our office set-up which include testing and calibrating sensors, testing the PID loop which we had implemented, running 3-phase motors with our systems and off all testing the whole set-up which we are building. 

But when we tested the same set-up on the client side, we realize the needness of getting on the road when you are building some thing from home and that too in the field of Embedded system, you cannot simply rely on the office test-set-up conditions and believe that system which we had build is robust, reliable and will work in every conditions. Believe me, real time conditions on any site where we are going to install our system very much vary from what we had in our office set-up. Below are certain examples of what i experienced while installing one of the Intelligent humidifier in the greenhouse in Bangalore along with my boss. 

  1. Sensor Calibration : We a using a humidity sensor in our project that is highly accurate and we had got certificate of calibration from the manufacturer with respect to the  calibration. We tested the same sensor in our office with the help of a humidifier which was making too small water droplets varying from 5 micron to 10 micron that would ideally increase the humidity while when we were in greenhouse, we faced that the droplets which their fogger/sprinkler were making were much more bigger than we assumed and that is why they settled on the ground very fastly resulting in dropping the humidity level. Along with that as we had kept our humidity sensor inside a filter so that it measure humidity and not the water vapor. But we had kept our sensor with filter directly exposed to the fogger, water particles accumulate on the outer-filter and thus even though fogger was turned off, our sensor was still measuring increase in the humidity. This give us a sense that we don't have to expose sensor + filetr directly to the fogger. Also we came to know that greenhouse need to use low volume foggers. Also in the evening if the soil is wet due to over-fogging, water will evaporate which will result in the increase in humidity measured by the sensor.
    Foggers in greenhosue/polyhouse
  2. Length of I2C sensor wire:  while being in office, we were not thinking in the direction that we even will be require to extend the length of the i2c sensor wire that we are using in our solution. At present we were only working with a sensor wire that is only 22 ft long and while we are implanting this thing in a greenhouse, we will always think of cost optimization for both, for our organization and for the end costumer. As a i2c line can accommodate 128 sensors, a person can add 128 sensor(well i cannot and i will never try!!!!), but still with our 1 data-logger, we can atleast add 10 sensor with different i2c address, can place them in 10 different chambers in a greenhouse and can thus control 10 different systems to maintain respective chambers variables. Well in order to use 1 data-logger, we will be required to use long i2c sensor wire. Well this thing arise , when we were in process of testing our solution at client side. Well there are certain ways with which you can extend the length of i2c sensor wire to 10-20 meter and certain by which  you can extend the length to 100 meter.  
    Generally Greenhouse/polyhouse chambers are big and sensor need to be placed in different positions
  3. Heating issues :  Inside a greenhouse/polyhouse, temperature is generally high. So when we were working inside the greenhouse and my boss was writing down some code for simulating the environment, i saw him dipped in sweat, just because of the high environment. At that time, i though of the case of using less heat emiting parts in our pcb, like linear voltage regulators etc. 
There were certain other issues that occur like low power consumption and wireless requirement. We are already implementing wireless solution in the same greenhouse and my previous post on the same. And as per the low power requirement, PCB iteration-2 is already on its development which will have micro-controller running on 3.3 volts. I hope that i will update soon with respect to the new iteration of PCB and further progress on the WSN implementation. 
          

Monday, 18 August 2014

My Last visit to a Greenhouse for Wireless Sensor Network Experiment

Trip to a Greenhouse in Tamil Nadu- WSN experiment. 

It was 13th of Aug afternoon, we left our office (me and Srinivas) to our way to A greenhouse located on the border of Karnataka and Tamil Nadu. I had visited that greenhouse with my boss a day ago and today we were require to go over there to conduct a WSN(Wireless sensor network) experiment. That greenhouse was approximately 32km form our Bangalore office and we decide not to take bus but rather take scooty of one of our colleague. And here we were on scooty, on our way to greenhouse. 

Our sole objective of conducting WSN experiment in that greenhouse was to test the LOS and Non LOS range of the wireless modules that we are using and to test the capability of wireless transmission of data which we had tested earlier in our office. It is always true that to test the real efficiency of a system, test it out in the field away from resources rather than testing it in office. In the same greenhouse we had already deployed our GPRS/GSM equipped temperature logger, that is continually sending data to our IOT cloud ,which they can access through a login and android app, can get notification based on alert rules they had put in their login.
Yuktix IOT based temperature logger




So this was some thing that can measure the temperature and humidity of the location or a specific chamber where this logger is kept or maximum we can do is we can add 4-5 more sensors, keep them in different chambers and read the data from them. But for that we need to keep the limitation of I2C bus that without I2C extender, we cannot extend the range of the wire beyond a certain limit (although we can, but them we need to compromise the frequency of I2C bus). But again, what if we want to the measure the temperature and humidity variable of a chamber which is almost 500 meter away from the place where my datalogger is kept. Ideally they don't want to make every sensor unit equipped with GSM/GPRS as it wouldn't them meet their financial criteria. 

So we propose them, that we can deploy a wireless sensor network in their greenhouse and can get sensor data from the remote unit with in the range of our wireless module which is absolutely limited(it cannot be more than few km, apart from the fact that we use 5.8 Ghz modules with 14 Dbi or 22 Dbi patch antenna which will again be worthless if we take in count their cost, effort and other technical specifications like compatibility with our solution etc). SO we decided to hookup with Zigbee and continue our WSN experiment rather then going with RF modules which are again prone to noise.

We decided to start with 3 end-node(slave) sensor equipped with our Zigbee module, 1 repeater(coordinator) and 1 control unit or master . We started with testing the range of the module in reality in the field(they always say that it will work for 1-2 km but believe me in real time conditions without a patch antenna it wouldn't go beyond 500 meters). Although we had tested the same modules in our office region which had many obstructions and we got a range of 50 meter(Non-LOS).

Rhutvik doing WSN range experiment near office 
While when we tried out the same experiment in LOS in greenhouse, we got a range of approx 350-400 meter and we were very much satisfied with the same. We tested our experiment with a temperature and humidity sensor plugged to our DL box with Zigbee module attached and we were moving in the field with master module attached to the laptop.

Srinivas conducting WSN experiment in the field.
So at present we conducted the range experiment with only temperature and soil sensor. On our second visit, we had decided that we will test out the same experiment by adding Soil sensor(Soil Mositure and Temperature), Air humidity and Temperature and Lux sensor with 1 repeater and 1 master. Along with creating a sensor network, we will also find out the power consumption of repeater(we are trying to equip our Zigbee repeater with solar power ). Our sensor-end node are already low power consuming sensor nodes, which go in sleep mode after sending the data to the master but still we need to figure out the exact amount of the power consumption. Below is the glimpse of what we will be trying in our next visit.