嵌入式gpio控制led灯代码实验报告

Introduction

In this experiment, we will learn how to control a LED light using the General Purpose Input/Output (GPIO) of an embedded system. GPIO is a versatile interface that allows us to interface with different electronic components, like sensors, motors, and of course, LED lights. For this experiment, we will use a Raspberry Pi as our embedded system and write code to control the LED using the GPIO pins.

Experiment Setup

To perform this experiment, we need the following components:

• Raspberry Pi (any model)
• Breadboard
• LED light
• Resistor (220Ω)
• Jumper wires

The circuit diagram for this experiment is straightforward. We connect the long leg of the LED to the GPIO pin 18 of the Raspberry Pi, which is also marked as PIN 12 on the board. Next, we connect the short leg of the LED to the resistor and then to the ground (GND) of the Raspberry Pi. Finally, we connect a jumper wire from the 3.3V power (3V3) of the Raspberry Pi to the other end of the resistor. This completes our circuit, and we are ready to write code to turn on and off the LED light.

Code Implementation

We will write the code in Python, which is a popular language for programming Raspberry Pi. First, we need to import the necessary libraries, which are RPi.GPIO and time. The RPi.GPIO library provides us with methods to set up and control the GPIO pins, while time library provides us with the necessary functions to delay the program execution.

Once we have imported the libraries, we need to set up the GPIO pin 18 as an output pin. We can do that using the setup method of the RPi. GPIO library as follows:

```
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BOARD)
GPIO.setup(12, GPIO.OUT)
```

This code sets up the GPIO pin 18 (PIN 12) as an output pin. Next, we can turn on and off the LED light using the following code:

```
GPIO.output(12, True)
time.sleep(1)
GPIO.output(12, False)
time.sleep(1)
```

The first line turns on the LED light by setting the GPIO pin 18 to high. We then wait for one second using the sleep method provided by the time library. Next, we turn off the LED light by setting the GPIO pin 18 to low, and then wait for another second before repeating the cycle.

Conclusion

In conclusion, we have learned how to control a LED light using the GPIO pins of an embedded system. We used a Raspberry Pi to demonstrate the concept, but the same code can be adapted to work with other embedded systems as well. By using GPIO pins, we can interface with different electronic components and create complex projects. In the future, we can use what we have learned in this experiment to interface with sensors, motors, and other electronic components using the GPIO pins.