B. The LCD Display
The display used is a 16x2 character LCD display with HD44780U dot-matrix liquid crystal display driver and
controller. The LCD is wired in 8-bit mode. The data pins of the LCD are connected to PORTB of ATmega16A and the RS,
R/W and E pins of LCD are respectively connected to PD0, PD1 and PD2.
V. WORKING AND CIRCUIT DIAGRAM
Once the ATMEGA 16A microcontroller is turned on, it initializes the LCD using the user-defined library ‘lcdlib’ and
also pins 33-40 function as a 10 bit analog to digital converter using the library ‘adc10bit’. The LCD is initialized so as to
display the internal and external temperature in its two rows with the accuracy of two decimal places. The LM 35
temperature sensors, one placed near the egg and the other external to the incubator, are given the proper supply and the
middle pin of the LM35 ic returns the voltage equivalent of the temperature to the adc. The adc converts the voltage from
the two LM35 ics (10mV = 1°C) and displays both the egg and external temperature on the LCD.
Fig. 1 Block Diagram
Since the optimum temperature for egg incubation is between 37 and 38.5°C, the microcontroller constantly check
the temperature returned from the LM35 temperature sensors. For this 1000 samples of the adc are taken and their average
is computed. The temperature is computed to two decimal places using mathematical operations and a suitable correction
factor is applied to rectify an error due to the external reference voltage. If the value of temperature lies below the optimum
range, a high voltage is given through pin 23 of the microcontroller to the base of transistor T1 to trigger the relay. The
triggering of the relay turns on the incandescent lamp through a 230V supply and the circulating fan through a 12V supply.
The heat from the incandescent lamp increases the temperature of the air and this is circulated inside the incubator using the
fan. This process continues till the temperature reaches above 38.5°C. Once this range is exceeded the relay is turned off
and the incandescent lamp and the fan get turned off, till the temperature goes below the lower limit again. Two LEDs are
B. The LCD Display
The display used is a 16x2 character LCD display with HD44780U dot-matrix liquid crystal display driver and
controller. The LCD is wired in 8-bit mode. The data pins of the LCD are connected to PORTB of ATmega16A and the RS,
R/W and E pins of LCD are respectively connected to PD0, PD1 and PD2.
V. WORKING AND CIRCUIT DIAGRAM
Once the ATMEGA 16A microcontroller is turned on, it initializes the LCD using the user-defined library ‘lcdlib’ and
also pins 33-40 function as a 10 bit analog to digital converter using the library ‘adc10bit’. The LCD is initialized so as to
display the internal and external temperature in its two rows with the accuracy of two decimal places. The LM 35
temperature sensors, one placed near the egg and the other external to the incubator, are given the proper supply and the
middle pin of the LM35 ic returns the voltage equivalent of the temperature to the adc. The adc converts the voltage from
the two LM35 ics (10mV = 1°C) and displays both the egg and external temperature on the LCD.
Fig. 1 Block Diagram
Since the optimum temperature for egg incubation is between 37 and 38.5°C, the microcontroller constantly check
the temperature returned from the LM35 temperature sensors. For this 1000 samples of the adc are taken and their average
is computed. The temperature is computed to two decimal places using mathematical operations and a suitable correction
factor is applied to rectify an error due to the external reference voltage. If the value of temperature lies below the optimum
range, a high voltage is given through pin 23 of the microcontroller to the base of transistor T1 to trigger the relay. The
triggering of the relay turns on the incandescent lamp through a 230V supply and the circulating fan through a 12V supply.
The heat from the incandescent lamp increases the temperature of the air and this is circulated inside the incubator using the
fan. This process continues till the temperature reaches above 38.5°C. Once this range is exceeded the relay is turned off
and the incandescent lamp and the fan get turned off, till the temperature goes below the lower limit again. Two LEDs are
การแปล กรุณารอสักครู่..
