Precision Digital Controller using PSoC CY8C PI Microcontroller

Transcription

1 Precision Digital Controller using PSoC CYC-PI Microcontroller Abstract The specific objective of this project is to design a precision digital controller for fully automatic microcontroller controlled reaction vessels for use in development and manufacture of fine chemicals and bio-engineering products, drugs and their intermediates with a high mass transfer efficiency. Such applications impose stringent requirements on temperature maintenance, ph maintenance, foaming, and oxygen content over extended periods of time even exceeding hours. Such a facility would help research labs and pharmaceuticals to define application specific control formats for multi loop and cascade control configurations. Presently the analog version of the controller is available. This analog version has to be converted into digital controller without altering the existing system. Also the system cost should be less and give higher performance compared to the analog controller. The current project is being implemented on the existing system in digital form. The heart of the system is the microcontroller CYC-PI from Cypress Microsystems. The manufacturer provides us with a microcontroller that can be configured according to our application. In the microcontroller, we use the ADC, PWM, PGA and Timer blocks configured according to our application. The application uses analog signals which are provided to the pins of port 0, through which the analog signals are fed to a multiplexer which selects the input channel and in-turn feeds bit ADC through a Programmable Gain Amplifier (PGA). There are -bit PWMs that are used to control the motors to control the flow of different parameters such as acid, alkali, antifoam and oxygen. Other pins of port 0 are configured as PWM outputs. A LCD panel is connected to Port to display the values of different parameters dynamically. A -bit data bus configuration is used to control the LCD. Port is used to control different motors and heaters, these are controlled by on-off mechanism. Also an audio buzzer is connected to port for any warnings on over range in some parameters. A timer module in the device is utilized to countdown on time. The motors are driven using MOSFETs for achieve more power efficiency. The sensors for the different parameters come along with the signal conditioners, which provide outputs of 0-V or -0mA drive. The outputs from the sensor signal conditioners are directly given to the ADC inputs of the microcontroller. The power supply section consists of two transformers, one to supply V at A to the digital system after regulation and the other to supply V at A for the motors. In the present project only the automatic mode is used where the keyboard input is not taken for providing limit (Upper and Lower) values for different parameters. This feature will be added in the future upgrade of the project. The block diagram of the Precision Digital Controller is shown in Fig. PSoC Design Challenge-00, Project Id - 9

2 Sensors and Signal Conditioners P0 P LCD x Microcontroller CYC-PI Motor Drivers P0 P Keyboard x V Power Supply P Buzzer for Alarm Crystal. KHz Fig. Block Diagram of Precision Digital Controller PSoC Design Challenge-00, Project Id - 9

3 J 0V AC Input S Mains Switch Power Supply for Microcontroller and LCD F A T 9V A D - 00V A Bridge C 00uF V C 0.uF U IN LM0 GND OUT C 0.uF J - VCC=V F A T V A D - 00V A Bridge C 00uF V U IN LT0 R K C 0.uF Tant D RED LED ADJ OUT C0 0.uF Tant R 00E R.K C9 0.uF Tant J - V Power Supply for Motors Title Precision D igital C ontroller - Power Supply Size Document Number Rev A Date: Sunday, June 0, 00 Sheet of PSoC Design Challenge-00, Project Id - 9

4 9 J - VCC=V VCC Precision Digital Controller VCC Analog Input from Signal Conditioners B - Buzzer V DC Buzzer J Analog In Buzzer R K Microcontroller Section R K Motor Motor Motor Buzzer U P0[0] P0[] P0[] P0[] 0 P[0] P[] P[] P[] P[]/External Agnd P[] P[]/Ext ernal Vref P[] P[]/Crysin/SCLK P[0]/Crysout/SDAT A SMP VCC C 0.uF P0[] P0[] P0[] P0[] P[] P[] P[] P[] P[] P[] Motor Motor Motor Motor 0 R 0K VCC J 9 0 LCD LCD Section J LCD 9 0 U VSS CO N VDD RS R/W E D0 9 D 0 D D D D D D Vled LCD x K Keyboard x A C B D Y. KHz C pf CY C-PI C pf VSS Xres 9 R 0E S Reset VCC Motor Motor Motor Motor Motor Motor Motor J Motor Title Precision Digital Controller - Microcontroller Size Document Number Rev B Date: Saturday, May, 00 Sheet of PSoC Design Challenge-00, Project Id - 9

5 J9 J0 J J - Motor - Motor - Motor - Motor J - V C 0.uF/0V D C D C D C D C N00 0.uF/0V N00 0.uF/0V N00 0.uF/0V N00 0.uF/0V Q IRF0 Q IRF0 Q IRF0 Q IRF0 Motor Motor Motor Motor Motor Motor Motor J Motor J Motor R 0E R0 0E R9 0E R 0E R 0E R 0E R 0E J - Motor J - Motor J - Motor D C D9 C D0 C N00 0.uF/0V N00 0.uF/0V N00 0.uF/0V Q IRF0 Q IRF0 Q IRF0 Title Presion D igital C ontroller - Motor C ontroller Size Document Number Rev A Date: Saturday, May, 00 Sheet of PSoC Design Challenge-00, Project Id - 9

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