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Fused Deposition Modeling (FDM) is a widely used method of rapid prototyping , new product development and design, functional testing and other aspects of products have played an increasingly important role . In recent years, our FDM technology has developed rapidly , but compared with foreign advanced technology there are still large gaps. FDM head is an important part of the system , because of its performance is directly related to the stability of the system , validity and accuracy. Nozzle is heated to melt the material wire, heating temperature should be reliable and accurate , or affect the speed of the wire , resulting in artifacts that it will not smooth. This paper describes a microcontroller-based embedded operating system and μC/OS- Ⅱ temperature control systems. Thermostat -off through the bidirectional thyristor to change the effective voltage across the load , the heating power to change the system so that the temperature is kept constant. Hardware circuit comprising : Function keypad, LCD display module, data acquisition circuit , 51 and actuators. First, the temperature sensor the temperature signal into a voltage signal, and then the A / D converter converts the digital signal, the microcontroller reads these signals and a PID algorithm for processing , the processing result is output to the D / A converter, the final output to the Executive device - Triac trigger circuit. Keyboard is used to set control parameters , LCD display output temperature values. The system requires software to implement various functions . According to the different tasks will be divided into four modules software components : acquisition tasks , processing tasks , the keyboard interrupt service and communication processing . To effectively manage secure access to a variety of tasks and a variety of shared variables introduced μC/OS- Ⅱ embedded operating system. Operating system scheduler various tasks , and to achieve synchronization between tasks running . In addition, the system can also communicate with a PC via PC to display and set various parameters . The design of the temperature controller that will effectively control the temperature of the nozzle , which greatly improve the molding accuracy of FDM .
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