METHODOLOGY
9
AEIE, RCCIIT
NodeMcu provides access to the GPIO (General Purpose Input/Output) and a pin mapping table
is part of the API documentation.
I/O Index
ESP8266 pin
0[*]
GPIO16
1
GPIO5
2
GPIO4
3
GPIO3
4
GPIO2
5
GPIO14
6
GPIO12
7
GPIO13
8
GPIO15
9
GPIO3
10
GPIO1
11
GPIO9
12
GPIO10
Table 2.1: GPIO pin mapping table of NodeMcu
A simple hardware programming language called processing, which is similar to the C language
loaded into the Arduino UNO forms the embedded software.
METHODOLOGY
10
AEIE, RCCIIT
Figure 2.2: Block Diagram of Automatic Solar Tracking System
Before being consolidated into one system, three independent stages are engineered independently.
This approach, similar to stepwise refinement in modular programming, has been employed as it
ensures an accurate and logical approach which is straight forward and easy to understand. This
also ensures that if there are any errors, they are independently considered and corrected.
METHODOLOGY
11
AEIE, RCCIIT
2.2 THEORY OF USING TWO LDR
Figure 2.3: Concept of using Two LDR
The figure depicts the notion for the instalment of the light dependent resistors (LDR). A secure
state is attained when the light intensities of the two LDR become the same. The principal source
of light energy, the Sun, moves from east to west. This movement of the Sun causes the variation
in the level of light intensities falling on the two LDRs. The designed algorithm compares the
variation in the light intensities inside the microcontroller and the motor
then is operated to rotate
the solar panel, so it moves aligned with the trail of the light source.
