PIC18f452 serial Data acquisition for Temperature Monitoring

Introduction of Data Logger Project:-

This is project is about the construction of simple data logger using PIC microcontroller PIC18f452 and Visual basic-6 VB6.
The project is consist of two posts:

1. In the first post, we will discuss the Hardware of Data acquisition Unit and the programming of PIC Microcontroller PIC18f452.
2. The second post will be about the development of PC side code, the Data logger is designed and developed using Visual basic VB6 programming language.
pic16f877 uart code
Hardware of Data acquisition Unit:-
This is a simple example project for the understanding of how data loggers and data acquisitions systems works. Students can design the project their won after reading the post.

Componenets List:-

The components used in this Project are as follows:-
1. The heart of the data acquisition (DAQ )is PIC18f452 microcontroller
2. Crystal used is 20MHz
3. Capacitors used are 20pF
4. Push buton for manual reset
5. Liquid crystal Display LCD 2 line 20 Characters
6. LM35 the analog temperature sensor
7. variable resistor 10K ohm to set the contrast of LCD
8. 10K ohm pull up resistor
9. 5V DC regulated power supply

Features of Data acquisition Unit:-
1. The PIC18f452 have 8 buitin analog to digital converters ADC of 10 bits resulations. So we have used only one builtin ADC to convert the analog signals of Temperature from LM35.
2. Only one analog Temperature sensor LM35 is used to sense the temperature.
3. The software is written to take the average of 10 consective readings of ADC for smooth monitoring of temperature.
4. The measured temperature is display on LCD.
5. the progress of sampling is also shown on LCD.pic18f542 lcd
6. The average value of temperature is then transmitted to PC using serial communication through RS232 port at 9600 buad rate with setting 9600,N,8,1.pic data logger

Circuit diagram of Data acquisition Unit:-
temperature sensor lm35 circuit diagram pic project

This project in which PIC452 is used but in old post you can find data logger using pic 16f877a.

Software of Data acquisition Unit:-
We can say that it is thermometer uart.
The program for PIC18f452 is written in proton basic language and listing is as under.
UART CODE for PIC18f452 here max232 interfacing pc is used.
'****************************************************************
'* Name : Temperature_data_logger.BAS *
'* Author : Dr.Rana *
'* Date : 22/9/2011 *
'* Version : 1.0 *
'* Notes : This is simple program for PIC18f452 *
'* : The LM25 sensor is connected to PIC452 *
'* The temperature measured is transfered to PC via *
'* serial port RS232 for temerature data logger *
'****************************************************************
Device = 18F452
Xtal=20 ' The crystal frequency is 20MHZ
LCD_DTPin PORTD.4 ' LCD is conected to PIC18f452 using four bit mode
LCD_RSPin PORTD.3
LCD_ENPin PORTD.2
Adin_Res 10 ' Set the resolution to 10
Adin_Tad FRC ' Choose the RC osc for ADC samples
Adin_Stime 100 ' Allow 100us for charge time
ADCON1 = %10000010 ' Set PORTA analog and right justify result
Input PORTA.0
TXSTA.5=1 ' setting Transmit Enable Bit
RCSTA.7=1
RCSTA.4=1
Hserial_Baud 9600 ' Setting Baud rate

Dim raw_adc_conversion As Word
Dim temperature As Float
Dim x As Byte
Print Cls
Print At 1,1,"T.Logger"
Loop:
raw_adc_conversion=0
For x=0 To 9
raw_adc_conversion = raw_adc_conversion + ADIn 0
DelayMS 200
Print At 1,10,"Samp.", Dec x
Next x
raw_adc_conversion = raw_adc_conversion/10
temperature = (5/1023) * raw_adc_conversion
temperature = temperature * 100
'1 degree centigrade for every 10mV
Print At 2,2,"Temp:", Dec temperature ,"C"
HRSOut Dec temperature,13,10
DelayMS 1000
GoTo Loop