1. Projekt ISSNB Nis, September 2007- 1 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service MICROPROCESSOR SYSTEM FOR MEASURING NON-ELECTRICAL QUANTITIES Zivko Kokolanski, Cvetan Gavrovski zivko.kokolanski@feit.ukim.edu.mk cvetang@feit.ukim.edu.mk

2. Projekt ISSNB Nis, September 2007- 2 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service OUTLINE STRUCTURE OF THE MEASURING SYSTEM MEASURING CIRCUITS - LLUMINANCE MEASUREMENT - TEMPERATURE MEASUREMENT - HUMIDITY MEASUREMENT - PRESSURE MEASUREMENT PROCESSING MODULE MEASURING ALGORITHM TECHNICALL CHARACTERISTICS CONCLUTION

3. Projekt ISSNB Nis, September 2007- 3 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service STRUCTURE OF THE MEASURING SYSTEM Processing Module Power Supply Display and Communication Analog Signal Processing

4. Projekt ISSNB Nis, September 2007- 4 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service ILLUMINANCE MEASUREMENT Photodiode: BPW34 high sensitivity fast response time visible and near IR (800nm) Most commonly used detectors: silicon photodiodes photoconductive cells Advantages of the photodiodes: higher sensitivity faster response time higher stability and linearity

5. Projekt ISSNB Nis, September 2007- 5 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service TEMPERATURE MEASUREMENT Thermistor KTY21-122 -55 to 150 o C non linear y = 0,0167x 2 + 7,0979x + 827,6

6. Projekt ISSNB Nis, September 2007- 6 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service HUMIDITY MEASUREMENT Sensor 808H5V6 capacitive type 0-100% RH

7. Projekt ISSNB Nis, September 2007- 7 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service PRESSURE MEASUREMENT Pressure sensor STS030A measuring strips based 0-2000 hPa 150 mV output voltage

8. Projekt ISSNB Nis, September 2007- 8 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service PROCESSING MODULE FE FD FC FF sync illuminance sync temperature sync humidity sync pressure Microcontroller PIC 16F877 4 bidirectional ports 8 channel 10 bit A/D converter

9. Projekt ISSNB Nis, September 2007- 9 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service MEASURING ALGORITHM PARAMETER SETTING LCD INITIALISATION SERIAL INTERFACE INITIALISATION A/D CONVERSION SETTING ILLUMINATION MEASUREMENT TEMPERATURE MEASUREMENT HUMIDITY MEASUREMENT PRESSURE MEASUREMENT A/D CONVERSION (20 SAMPLES) AVERAGING CORRECTION SERIAL TRANSMITION LCD WRITE

10. Projekt ISSNB Nis, September 2007- 10 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service TECHNICALL CHARACTERISTICS MeasurementMeasuring rangeResolutionAccuracy Illuminance0-10000 Lx10 Lx± 10 % Temperature-55-150 o C1 o C± 2 % Humidity0-100 %1 %± 4 % Pressure0 -2000 hPa2 hPa± 2 %

11. Projekt ISSNB Nis, September 2007- 11 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service CONCLUTION The presented paper describes a practical measuring system, which allows measurement, transfer and display of the moment values of four physical quantities: temperature, pressure, humidity and illumination The measuring system uses a serial RS-232 port for computer communication Further development of the measuring system is planned in future, in a way of enlarging the measuring quantities with measurements of ionizing radiation and wireless data transmission

12. Projekt ISSNB Nis, September 2007- 12 - DAAD Deutscher Akademischer Austausch Dienst German Academic Exchange Service THANK YOU!