【资料下载】

[] 原理图

[] ssd1306_oled_128x32.py

[] bad_apple_128x32.gif

【准备工作】

在开始之前，您需要以下物品：

[] 树莓派开发板

[] SSD1306 OLED屏幕-I2C显示接口

[] Python编程环境

硬件连接

打开I2C接口

在树莓派上确保开启I2C接口之后重启树莓派

查找I2C设备地址

您可以使用以下命令查找连接到树莓派上的I2C设备的地址：

sudo i2cdetect -y 1

运行结果如图所示（一般ssd1306oled的默认i2c地址为0x3c）

安装库

接下来，您需要在树莓派上安装luma.oled库。可以通过以下命令在终端中进行安装：

sudo pip3 install luma.oled

sudo apt-get install ttf-mscorefonts-installer

测试Python程序

运行代码之前需要在树莓派新建一个名为ssd1306_oled_128x32_bad_apple.py的python文件（文件名可自定义）

sudo nano ssd1306_oled_128x32_bad_apple.py

组合以上步骤，并使用luma.oled库驱动SSD1306 OLED屏幕，以下是一个完整的Python程序，用于在树莓派上驱动SSD1306 OLED屏幕：

import os

import time

import threading

from PIL import Image, ImageSequence

from PIL import ImageFont, ImageDraw

from luma.core.interface.serial import i2c

from luma.core.render import canvas

from luma.oled.device import ssd1306

serial = i2c(port=1, address=0x3C)

device = ssd1306(serial, width=128, height=32)

# Return CPU temperature as a character string

def getCPUtemperature():

    res = os.popen('vcgencmd measure_temp').readline()

    return(res.replace("temp=","").replace("'C\n",""))

# Return RAM information (unit=kb) in a list

# Index 0: total RAM

# Index 1: used RAM

# Index 2: free RAM

def getRAMinfo():

    p = os.popen('free')

    i = 0

    while 1:

        i = i + 1

        line = p.readline()

        if i==2:

            return(line.split()[1:4])

# Return % of CPU used by user as a character string

def getCPUuse():

    return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip()))

# Return information about disk space as a list (unit included)

# Index 0: total disk space

# Index 1: used disk space

# Index 2: remaining disk space

# Index 3: percentage of disk used

def getDiskSpace():

    p = os.popen("df -h /")

    i = 0

    while 1:

        i = i +1

        line = p.readline()

        if i==2:

            return(line.split()[1:5])

def draw_text(text, width, height, fontsize):

    font = ImageFont.truetype("arial.ttf", fontsize)

    with canvas(device) as draw:

        draw.rectangle(device.bounding_box, outline="white", fill="black")

        # Calculate the width of the text using textlength() instead of textsize()

        w = font.getlength(text)

        # Calculate the height of the text by subtracting the font descent from the font ascent

        ascent, descent = font.getmetrics()

        h = ascent - descent

        # Calculate the position of the text

        x = (width - w) // 2

        y = (height - h) // 2

        # Draw the text using the new width and height values

        draw.text((10, 1), text, font=font, fill="white")

def image_gif():

    # Display each image with an idea

    for frame in frames:

        device.display(frame)

        time.sleep(0.01)

def computer_resources(flag):

    while not flag.is_set():

        # CPU informatiom

        CPU_use = getCPUuse()

        CPU_tmp = getCPUtemperature()

        # RAM information

        # Output is in kb, here I convert it in Mb for readability

        RAM_stats = getRAMinfo()

        RAM_total = round(int(RAM_stats[0]) / 1000,1)

        RAM_used = round(int(RAM_stats[1]) / 1000,1)

        RAM_free = round(int(RAM_stats[2]) / 1000,1)

        # Disk information

        DISK_stats = getDiskSpace()

        DISK_total = DISK_stats[0]

        DISK_used = DISK_stats[1]

        DISK_perc = DISK_stats[3]

        #

        status_text = "CPU_use:  "+CPU_use+"\nCPU_tmp:  "+CPU_tmp

        draw_text(status_text, device.width, device.height, 12)

if __name__ == '__main__':

    # Open a GIF file and create an Image object for each frame

    frames = []

    with Image.open("./bad_apple_128x32.gif") as img:

        for frame in ImageSequence.Iterator(img):

            frames.append(frame.convert("1").resize((128,32)))

    # Create a threading.Event() object for synchronization

    flag = threading.Event()

    # Create a thread to compute system resources usage

    t = threading.Thread(target=computer_resources,args=(flag,))

    while True:

        # Show some text and wait for 2 seconds

        draw_text("www.spotpear.cn\nhttp://www.spotpear.com\n", device.width, device.height, 12)

        time.sleep(2)

        #Start the thread to compute system resources usage,wait for 5 seconds

        t.start()

        time.sleep(5)

        # Set the flag to stop the thread

        flag.set()

        # Wait for the thread to terminate

        t.join()

        # Clear the flag and create a new thread for next loop

        flag.clear()

        t = threading.Thread(target=computer_resources,args=(flag,))

        time.sleep(2)

        # Display Bad Apple animation as GIF images

        image_gif()

请注意，我们在i2c对象中使用了地址"0x3C"，这是默认的SSD1306 OLED屏幕地址。如果您使用的是其他类型的I2C设备，请使用命令

sudo i2cdetect -y 1查找其地址，并将其地址替换为i2c对象中的地址。

该程序实现了gif的显示效果，所以必须得有对应的gif文件，否则程序无法正常运行。如何转换视频为gif参考这个教程：MP4视频如何转化为gif

程序执行效果

上述代码输入到python文件内，保存并且退出，在树莓派终端输入以下代码即可执行程序：

sudo python3 ssd1306_oled_128x32_bad_apple.py

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