Research On Greenhouse Communication Platform Based On SMS/GPRS

Since 80's in last century when greenhouse has been developed quickly, our country has already become gradually the biggest nation on the area of the cultivation growth in the world. Glasshouse research gets the quick development. Currently, the investment of the local glasshouse is big, the production cost is high and it has higher request towards operating the personnel's character, but the glasshouse supervision manage the system efficiency lowly, operate inconvenient, for the sake of the quantity, yield, economic worth and social performance of the greenhouse product, we need to adopt the calculator technique and the network techniques of the forerunner, develop the software system and man-machine interfaces that function is strong, the efficiency is high and operate conveniently.The controls system of the environment of the traditional glasshouse requests the personnel who arrives at the spot and operates and controls the glasshouse himself. If not at the glasshouse, the personnel want to understand the glasshouse movement circumstance, or the technical personnel of the glasshouse manufactory to solve to control the system breakdown, they must attend personally the spot or pass the wired network and then can acquire the information need perhaps. Aimed at these circumstances, the purpose of this thesis is to actualize communications wireless in greenhouse that make the personnel who is on the scene get out the glasshouse information, make operate and control the glasshouse in time.The main communications wireless main technique using in this thesis are SMS and GPRS. SMS (Short Message Service) is the function business of the text information that has limited length sent out and received through a network of GSM. Its main advantages are these: the charge is cheap, sent out only 0.1 Yuan of one SMS each time, and accepted free; the customer of SMS can send out the SMS at any time and anywhere, need not to worry that the other party don't switch on again at service area or not at; Other lot of advantages, such as the overlay area is large, the delivered distance is free from the restrict, it need not by oneself a net, it is easy to expand to permit, installing is convenient and it don't need to support etc. The main weaknesses of SMS are: it can deliver the pure text, sketch or voices only; each SMS can't have more than 160 English letters of alphabets or 70 Chinese characters; the data delivers low, and wait for time long.The GPRS is a business of General Packet Radio Service. GPRS is applicable to deliver data interrupted, abrupt specially and multifarious or a little amount. Its main characteristics are: GPRS adopts the deliver of a commutation mode; the way of wireless channel distribution is quite agility; GPRS support to deliver data at high speed; the velocity connecting the network of GPRS is low; GPRS is on-line at anytime; the customer can keep with the conjunction of network at anytime; the charge way is more reasonable; the GPRS safe function is together with the GSM; the data and words sound businesses are coexistence, GPRS has a conjunction with the network of IP of the high-speed development. The main weaknesses of GPRS are: the actual velocity is low, GPRS postpones when transferring, the data wraps maybe lose; the total capacity is limit of small area.The main aspects of this thesis's research works and conclusions are these:⑴The detailed analysis studies the system constitutes of platform. The platform at structures are mainly several parts following: the part collecting the glasshouse information, the terminal controlled by G20 (Motorola communication module), the network of GSM/GPRS, network of internet,computer control centre etc. The thesis design the electric circuit of the terminal controlled by G20, including parts of electric circuit of the power supply, SIM card, USB connecting and signal lamp etc. which constituted the most basic part of platform.⑵The thesis discuss detailing the SMS concept, the flow receiving and dispatch, advantage and disadvantage etc. The thesis introduces the AT command and PDU format in the communication course using G20, analyzes the methods communicated using USB interface, gives the part programs of receiving and dispatching the SMS. Because the SMS long is short, therefore, transferring the greenhouse information using SMS is fit the complexion that the transmission frequency is low or the amount of data is small, such as giving an alarm, the long-distance control etc. ⑶The thesis detailed discusses the concept an characteristic of GPRS, analyzes the important communication protocols TCP, IP, PPP, analyzes the AT command about GPRS, gives the project of GPRS that using SMS notifies the GPRS get up the line and delivers the essential communication data wrap transferring. The advantage is that turning down the communication charge by depressing the communication flux reducing the data wrap of chain check. Using the network to transfer the greenhouse information has many advantages such as the transfer speed rapidly, implement online all time. Comparing with SMS, GPRS is adapted to transfer a lot of data, for example a great deal of examination data need to be transfer.⑷The thesis carries out the function design of greenhouse communication platform. The characteristic of platform are: the function is strong that the platform can use to give an alarm about the greenhouse information and transfer the greenhouse data using SMS; the platform has a high economical value that has a low cost combining the advantages of SMS and GPRS; operating the platform are easy; the platform has good characters of currency and agility that can also be applied in other field after adjusting and amending.