Weather-Monitoring-System

Weather Monitoring System which monitors the temperature and light intensity using analog sensors and plots the changes over a period of time.

Board

• Texas Instruments TM4C123GH6PM Tiva C Launchpad

Sensors

• LM35 Temperature Sensor

• Photoresistor

  

Other Components

• Breadboard
• Jumper Wires
• 2k ohm resistor

Languages and libraries used

• C

1. tm4c123gh6pm.h

• Python3

1. Tkinter
2. matplotlib
3. csv
4. datetime

Circuit Diagrams

Connections

• LM35

1. The LM35 has three pins.
2. The first pin is connected to Vcc of the board.
3. The second pin is the data pin, it is connected to AIN0 i.e. PE3 pin of the board.
4. The third pin is connected to the GND of the board.

• Photoresistor

1. The photoresistor has two pins.
2. The first pin is connected to the Vcc of the board.
3. The second pin is connected to

• The AIN1 i.e. PE2 pin on the board
• The GND pin of the board through a resistor

Working of the LM35 Sensor

• The LM35 is a frequently used temperature sensor. It is calibrated to degrees Celsius, ensuring that the readings obtained from the sensor are directly proportional to degrees Celsius values.
• The output voltage has a scale factor of 10mV per degree Celsius.
• The sensor has a range of -55 oC to 150 oC. Its accuracy ranges from 0.25 oC to 0.75 oC.
• The sensor has two configurations:

1. Basic Centigrade configuration
2. Full range Centigrade configuration

• Here, the basic configuration is used, which can measure temperature in the range of 2 - 150 oC.
• For our purposes, we convert the value obtained into a Fahrenheit value.
• The ADC channel in TM4C123GH6PM has 12 bits and a maximum of 4096 steps.
• The maximum operating temperature of the LM35 is 300F, consequently, the maximum output will be 3000mV i.e. 3 V.
• The resolution obtained in this case, using a Vref of 3.3V is

3.3V/4096 = 0.0008V = 0.8mV

• Equations to calculate the temperature

VOUT(mV) = 10mV/°C * T

T = (ADC_RESULT * VREF)/4096 * 0.01 °C

T = (ADC_RESULT * VREF * 100)/4096 °C

T = (ADC_RESULT * 330) / 4096 °C

Working of the Photoresistor

• The photoresistor has an inversely proportional relationship with the illumination.
• Here, with ADC of 12 bits, the value of light intensity is obtained as a percentage as

L = (ADC_RESULT) / 4096

Screenshots

Recorded Output

Instructions

1. Upload the C code to a TM4C123GH6PM board through IAR Workbench or Keil.
2. Make the required connections between the components.
3. Run the code through workbench.
4. Run the GUI.py code.
5. Open the serial connection between the GUI and the board through COM3 port's UART0 terminal, through the 'Open Connection' button.
6. Get the values of the Temperature and Light Intensity through the 'Weather' button.
7. Plot the values and observe the changes over the period of time through the 'Plot' button.
8. Close the connection and the window with the 'Close Connection' button.