Research Of Energy Microlgae Cultivating Monitoring System Based On CAN

With the rapid development of national economy，Human will face two major issues that theincreasing depletion of oil resources and environmental protection. Therefore, the development ofbio-energy has been paid increasingly attention by people. The oil from microalgae is one of themost perspective material for bio-diesel. The Bio-diesel industrial technology has become aresearch focus on the field of bio-energy at home and abroad and CO2emission reduction. Thesubject developed the energy microalagae cultivating and monitoring system based on CAN, whichrealized that the function of monitoring and controlling process parameters in the biological courseof cultivating the microalagae, which is mainly used for the optimized and enlarged research in thiscourse.Based on specific requirement of monitoring system in energy microalgae growing process,Using CAN bus can build the network of master-slave mode, a software and hardware method ofbuilding slave nodes is developed, which is based on STM32F107 .The hardware consisted of sixmajor components which is the node for collecting, the node for controlling, the node for measuringby instrument, the protocol converter, the central monitor and remote computer. Using Kingview6.53 which is the configuration software developed the software function for central monitor.The main work in this paper is divided into four parts: design overall program for monitoringsystem, design for hardware, design for software and test for system.The overall program for monitoring system mainly includes design for system integration,choosing sensors and actuators which are used in monitoring system, STM32F107 selected as thecore for the acquisition node and control node, used Kingview 6.53 to develop the monitoringsoftware.Based on functional requirement which needs to realize for the collecting node and thecontrolling node, It completed the hardware circuit design for them, mainly included the minimumsystem circuit with STM32F107, the power circuit, the sensors’signal conditioning circuit, theanalog channel switching circuit, the ADC circuit, the control circuit used by optical isolator, thepower driver circuit, the DAC circuit, the acquisition circuit for 0-5V voltage and the CANcommunication circuit with isolated function.Based on the hardware architecture, it showed the overall software structure of control system.Refered to the Modbus RTU protocol launched by Modicon company, it defined the communicationprotocol which can meet the requirements of reliability and expansion for monitoring system. Theslave-nodes’software adopted the modularization design, the software for collecting node included the program for channel switching and ADC, the program for segmentation process and theinterrupt service routine for receiving by CAN and so on. The software for controlling nodeincluded the interrupt service routine for receiving by CAN, the program for refreshing DACchannels and the program for switch output and so on. It described the software developmentprocess on platform of Kingview 6.53. It mainly achieved system overview display, sensorcalibration, parameter setting, real-time curve display, database storage and Web publishing.The testing result shows that the monitoring system can run under the band rate of 9600 bit/snormally, high stable and scalable. It has a wide application prospects in the bio-energy area.