INTRODUCTION This project is about to design and build a digital thermometer is lab environment. Presentation of temperature and a pulse with modulation (PWM) output signal.
PROJECT COMPONENTS & REQUIREMENTS Main Board AMTEL STK500 Card, Atinity 2313/V microprocessor and SMT16030 Digital Temperature Sensor which can measure temperature from - 45°C till +130°C. To build a sensor we have TO92 sensor, it has three pins and each pin is dedicated for separate duty, PIN 1 to OUTPUT PIN2 to VCC PIN3 to Ground
PROJECT DESCRIPTION This project aimed to design and build a digital thermometer, and should be able to show temperature from -45°C till +130°C. Project has three main parts: 1. Microprocessor Programming 2. Transmission of temperature signals to LED’s through RS232 connection 3. Showing Temperature on the FPGA board Because of lack of time and HW, we change the project scope and VHDL part eliminated, also for RS232 part we used PC connection and for showing temperature we use hyper terminal on PC.
OPERATIONAL PROCESS When we connect a sensor to the Main board sensor signals start communicate with main board but it should be translated in the way that can be understood by microprocessor. each signal contain Duty Cycle (D.C), D.C = Th/Tp, Tp = TH + TL D.C = 0.32 + 0.047 * t D.C*213 – 68 = t for T input is between 0 – 40 C Counting Counter block inside microprocessor
PROJECT PROCESS ICP Noise Cancelation Edge Detector ICF1
OPERATIONAL PROCESS Time Counter Control Register (TCCR1B) Time Counter Interrupt Flag Register (TIFR)
OPERATIONAL PROCESS Now we have temperature and it should be communicated through RS232 to PC Baud Rate BBRD // Speed 9600 or 2400 // Stop bits // Tx UCRSB, Buffer Microprocessor is faster than Tx RS232, we use buffer and other subroutines