Abstract:
A universal data logger with the ability to display measured values, can serve the needs of
professional data loggers in a wide variety o f applications. Such applications inelude Quality Assurance, Plant and Machine Condition Monitoring, Field Monitoring Stations, Automotive Testing, Monitoring Environmental Conditions, Food and Pharmaceutical Environmental Storage Monitoring, Water Quality Testing and also in an array o f research fields.
The present project work was thus, focused on designing and developing a cost-effective,
compact and a standardized data display system for a Universal Data Logger. As such, the
basic outline o f the instrument was designed to inelude two input channels independent of
each other, for measuring temperature and humidity and to display the relevant values
accordingly. The main approach adopted in designing the above was the study o f different
sensors to select the most appropriate sensor for the said purpose. Employing toe selected
components, a microcontroller based sensor interface circuit was designed initially, while
Firmware Programming using C language was employed to operate toe data logger. Finally,
familiarization o f toe MP Lab Integrated Development Environment and a “HI-TECH” C
compiler was obtained.
A P1C 16F876A microcontroller microchip was used as toe main device o f toe data collection system. The temperature is detected by a LM3S temperature sensor. The output o f toe LM3S is in toe form o f a voltage signal, which is in general very weak so an amplifier was used to
amplify this voltage. The output o f toe amplifier is fed into toe PIC microcontroller. The
inbuilt ADC o f toe PIC unit converts this analog data to digital form, with toe parallel data
received being converted to serial data by toe inbuilt USART. Firmware was tested with
hardware at bread board level and toe resulting values are displayed by means o f toe LCD
display.
Boto, toe temperature sensing unit and toe humidity sensing unit were designed & tested on breadboard level successfully. Though this was tested only for two parameters, toe same can also be done for several other parameters like pressure, viscosity, etc. This system is costeffective and time efficient in its operation and fimetions at a relatively high speed, very
accurately while being used for measurements.
