PC based Temperature data logging is a series of posts, in which we will tell a beginner to make all by itself.
Following tools will be required in this project:
1. Personal Computer PC having serial port.
2. PIC 16f877
3. Lm 35
4. 5 volt power supply.
6. misc. components as shown in circuit diagram.
PIC 16f877 have built in six adc of 10 bit resolutions. So no worry of using any external adc in this project. we will use one of them for analog to digital conversion. Lm35 is temperature sensor and gives us output in format of 10mv/C. The output pin of LM35 is directly connected to adc (0) of micro-controller. The results are taken into account by using program written in basic language using proton compiler. After having averaging out results the temperature is displayed on local LCD and as well as send to PC through serial port RS-232 on stander null modem 9600 baud rate. A program written VB-6 is used to get the incoming data and shows result on the computer screen. The data acquisition program have following features.
1. Finds out minimum value
2. of Finds out maximum value
3. Average value 10 sec
4. show instantaneous value
5. maintains real time graph to shows response of the system
6. saves history readings