树莓派/Jetson-OLED副屏教程
Jetson系列主控
1、GPIO引脚图
使用0.91寸OLED测试I2C通讯功能，按照下面接线进行连接：
注意：请勿接错或者造成引脚短路，失误可能导致主板硬件损坏！
2、I2C测试
2.1、安装依赖
PowerShell
sudo apt install -y python3-pip
sudo pip3 install smbus
sudo pip3 install Adafruit_SSD13062.2、I2C设备
正常开发过程中，我们需要查找I2C设备挂载的设备总线以及设备地址。
（1）查询I2C总线
终端输入下面命令可以列出设备所有总线：
PowerShell
i2cdetect -l（2）查询I2C设备
终端输入下面命令可以列出指定总线下的I2C设备：oled对应的I2C地址是 0x3c
PowerShell
i2cdetect -y -r *3、查看ip地址端口
使用 ifconfig 查看ip地址端口
根据实际端口更改代码
4、实验效果
创建创建Oled_i2c.py文件
PowerShell
sudo gedit Oled_i2c.py复制粘贴以下代码
Python
#!/usr/bin/env python3
# coding=utf-8
import time
import os
import sys
i2c_num = 7
if len(sys.argv) > 1:
if str(sys.argv[1]).isdigit():
i2c_num = int(sys.argv[1])
print("i2c_num=", i2c_num)
passwd = "juxi"
cmd_i2c = "sudo i2cdetect -y -r " + str(i2c_num)
os.system('echo %s | sudo -S %s' % (passwd, cmd_i2c))
import Adafruit_SSD1306 as SSD
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
import subprocess
class Juxi_OLED:
def __init__(self, i2c_bus=1, debug=False):
self.__debug = debug
self.__i2c_bus = i2c_bus
self.__top = -2
self.__x = 0
self.__total_last = 0
self.__idle_last = 0
self.__str_CPU = "CPU:0%"
def __del__(self):
if self.__debug:
print("---OLED-DEL---")
# 初始化OLED，成功返回:True，失败返回:False
# Initialize OLED, return True on success, False on failure
def begin(self):
try:
self.__oled = SSD.SSD1306_128_32(
rst=None, i2c_bus=self.__i2c_bus, gpio=1)
self.__oled.begin()
self.__oled.clear()
self.__oled.display()
self.__width = self.__oled.width
self.__height = self.__oled.height
self.__image = Image.new('1', (self.__width, self.__height))
self.__draw = ImageDraw.Draw(self.__image)
self.__font = ImageFont.truetype("DejaVuSansMono.ttf",8) # ImageFont.load_default()
if self.__debug:
print("---OLED begin ok!---")
return True
except:
if self.__debug:
print("---OLED no found!---")
return False
# 清除显示。refresh=True立即刷新，refresh=False不刷新。
# Clear the display. Refresh =True Refresh immediately, refresh=False refresh not
def clear(self, refresh=False):
self.__draw.rectangle(
(0, 0, self.__width, self.__height), outline=0, fill=0)
if refresh:
self.refresh()
# 增加字符。start_x start_y表示开始的点。text是要增加的字符。
# refresh=True立即刷新，refresh=False不刷新。
# Add characters. Start_x Start_y indicates the starting point. Text is the character to be added
# Refresh =True Refresh immediately, refresh=False refresh not
def add_text(self, start_x, start_y, text, refresh=False):
if start_x > 128 or start_x < 0 or start_y < 0 or start_y > 32:
if self.__debug:
print("oled text: x, y input error!")
return
x = int(start_x + self.__x)
y = int(start_y + self.__top)
self.__draw.text((x, y), str(text), font=self.__font, fill=255)
if refresh:
self.refresh()
# 写入一行字符text。refresh=True立即刷新，refresh=False不刷新。
# line=[1, 4]
# Write a line of character text. Refresh =True Refresh immediately, refresh=False refresh not.
def add_line(self, text, line=1, refresh=False):
if line < 1 or line > 4:
if self.__debug:
print("oled line input error!")
return
y = int(8 * (line - 1))
self.add_text(0, y, text, refresh)
# 刷新OLED，显示内容
# Refresh the OLED to display the content
def refresh(self):
self.__oled.image(self.__image)
self.__oled.display()
# 读取CPU占用率
# Read the CPU usage rate
def getCPULoadRate(self, index):
count = 10
if index == 0:
f1 = os.popen("cat /proc/stat", 'r')
stat1 = f1.readline()
data_1 = []
for i in range(count):
data_1.append(int(stat1.split(' ')[i+2]))
self.__total_last = data_1[0]+data_1[1]+data_1[2]+data_1[3] + \
data_1[4]+data_1[5]+data_1[6]+data_1[7]+data_1[8]+data_1[9]
self.__idle_last = data_1[3]
elif index == 4:
f2 = os.popen("cat /proc/stat", 'r')
stat2 = f2.readline()
data_2 = []
for i in range(count):
data_2.append(int(stat2.split(' ')[i+2]))
total_now = data_2[0]+data_2[1]+data_2[2]+data_2[3] + \
data_2[4]+data_2[5]+data_2[6]+data_2[7]+data_2[8]+data_2[9]
idle_now = data_2[3]
total = int(total_now - self.__total_last)
idle = int(idle_now - self.__idle_last)
usage = int(total - idle)
usageRate = int(float(usage / total) * 100)
self.__str_CPU = "CPU:" + str(usageRate) + "%"
self.__total_last = 0
self.__idle_last = 0
return self.__str_CPU
# 读取系统时间
# Read system time
def getSystemTime(self):
cmd = "date +%H:%M:%S"
date_time = subprocess.check_output(cmd, shell=True)
str_Time = str(date_time).lstrip('b\'')
str_Time = str_Time.rstrip('\\n\'')
return str_Time
# 读取内存占用率 和 总内存
# Read the memory usage and total memory
def getUsagedRAM(self):
cmd = "free | awk 'NR==2{printf \"RAM:%2d%% -> %.1fGB \", 100*($2-$7)/$2, ($2/1048576.0)}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip('b\'')
str_FreeRam = str_FreeRam.rstrip('\'')
return str_FreeRam
# 读取空闲的内存 / 总内存
# Read free memory/total memory
def getFreeRAM(self):
cmd = "free -h | awk 'NR==2{printf \"RAM: %.1f/%.1fGB \", $7,$2}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip('b\'')
str_FreeRam = str_FreeRam.rstrip('\'')
return str_FreeRam
# 读取TF卡空间占用率 / TF卡总空间
# Read the TF card space usage/TOTAL TF card space
def getUsagedDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"SDC:%s -> %.1fGB\", $5, $2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip('b\'')
str_Disk = str_Disk.rstrip('\'')
return str_Disk
# 读取空闲的TF卡空间 / TF卡总空间
# Read the free TF card space/total TF card space
def getFreeDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"Disk:%.1f/%.1fGB\", $4,$2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip('b\'')
str_Disk = str_Disk.rstrip('\'')
return str_Disk
# 获取本机IP
# Read the local IP address
def getLocalIP(self):
ip = os.popen(
"/sbin/ifconfig enP8p1s0 | grep 'inet' | awk '{print $2}'").read()
ip = ip[0: ip.find('\n')]
if(ip == ''):
ip = os.popen(
"/sbin/ifconfig wlP1p1s0 | grep 'inet' | awk '{print $2}'").read()
ip = ip[0: ip.find('\n')]
if(ip == ''):
ip = 'x.x.x.x'
if len(ip) > 15:
ip = 'x.x.x.x'
return ip
# oled主要运行函数，在while循环里调用，可实现热插拔功能。
# Oled mainly runs functions that are called in a while loop and can be hot-pluggable
def main_program(self):
state = False
try:
cpu_index = 0
state = self.begin()
while state:
self.clear()
str_CPU = self.getCPULoadRate(cpu_index)
str_Time = self.getSystemTime()
if cpu_index == 0:
str_FreeRAM = self.getUsagedRAM()
str_Disk = self.getUsagedDisk()
str_IP = "IPA:" + self.getLocalIP()
self.add_text(0, 0, str_CPU)
self.add_text(50, 0, str_Time)
self.add_line(str_FreeRAM, 2)
self.add_line(str_Disk, 3)
self.add_line(str_IP, 4)
self.refresh()
cpu_index = cpu_index + 1
if cpu_index >= 5:
cpu_index = 0
time.sleep(.1)
except:
if self.__debug:
print("!!!---OLED refresh error---!!!")
pass
if __name__ == "__main__":
try:
oled = Juxi_OLED(i2c_num, debug=True)
while True:
oled.main_program()
time.sleep(2)
except KeyboardInterrupt:
oled.clear(True)
del oled
print(" Program closed! ")
pass启动程序后，OLED会显示系统CPU占用率、系统时间以及内存占用率等系统信息：
树莓派、香橙派
1.打开I2C选项
进入树莓派系统设置，选择：首选项→Raspberry Pi Configuration→Interfaces→找到I2C选项打开 然后会重启系统即可。（参考下图）
如果你在命令模式下，可输入sudo raspi-config依然可以找到该选项打开I2C然后重启一下系统即可。
2.安装I2C库文件
PowerShell
sudo apt install -y python3-dev
sudo apt install -y python3-smbus i2c-tools
sudo apt install -y python3-pil
sudo apt install -y python3-pip
sudo apt install -y python3-setuptools
sudo apt install -y python3-rpi.gpio
sudo apt install -y python3-venv我这里使用的是Python3，安装I2C库后，使用i2cdetect命令查询显示屏模块是否被识别
PowerShell
i2cdetect -y 1显示该设备已被检测到地址为"0x3c"（如下图）此类型设备的默认是十六进制地址。
3.字体文件配置
代码中使用了 DejaVuSansMono.ttf 字体：
PowerShell
sudo apt-get install -y fonts-dejavu-core或修改代码为系统已有的字体（如 ImageFont.load_default()）
4.权限配置
确保 I2C 设备文件权限正确：
PowerShell
sudo chmod a+rw /dev/i2c-* # 临时生效，永久生效需配置 udev 规则5.查看ip地址端口
使用 ifconfig 查看实际的ip地址端口
PowerShell
# （如未安装net-tools）sudo apt install net-tools
ifconfig根据实际端口更改代码中以下两个框选的内容
6.创建Oled_i2c.py文件
在Home目录下创建Oled_i2c.py文件
PowerShell
# （如未安装gedit） sudo apt install gedit
sudo gedit Oled_i2c.py复制以下代码粘贴到文件里面，保存关闭
Python
#!/usr/bin/env python3
# coding=utf-8
import time
import os
import sys
i2c_num = 7
if len(sys.argv) > 1:
if str(sys.argv[1]).isdigit():
i2c_num = int(sys.argv[1])
print("i2c_num=", i2c_num)
passwd = "juxi"
cmd_i2c = "sudo i2cdetect -y -r " + str(i2c_num)
os.system('echo %s | sudo -S %s' % (passwd, cmd_i2c))
import Adafruit_SSD1306 as SSD
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
import subprocess
class Juxi_OLED:
def __init__(self, i2c_bus=1, debug=False):
self.__debug = debug
self.__i2c_bus = i2c_bus
self.__top = -2
self.__x = 0
self.__total_last = 0
self.__idle_last = 0
self.__str_CPU = "CPU:0%"
def __del__(self):
if self.__debug:
print("---OLED-DEL---")
# 初始化OLED，成功返回:True，失败返回:False
# Initialize OLED, return True on success, False on failure
def begin(self):
try:
self.__oled = SSD.SSD1306_128_32(
rst=None, i2c_bus=self.__i2c_bus, gpio=1)
self.__oled.begin()
self.__oled.clear()
self.__oled.display()
self.__width = self.__oled.width
self.__height = self.__oled.height
self.__image = Image.new('1', (self.__width, self.__height))
self.__draw = ImageDraw.Draw(self.__image)
self.__font = ImageFont.truetype("DejaVuSansMono.ttf",8) # ImageFont.load_default()
if self.__debug:
print("---OLED begin ok!---")
return True
except:
if self.__debug:
print("---OLED no found!---")
return False
# 清除显示。refresh=True立即刷新，refresh=False不刷新。
# Clear the display. Refresh =True Refresh immediately, refresh=False refresh not
def clear(self, refresh=False):
self.__draw.rectangle(
(0, 0, self.__width, self.__height), outline=0, fill=0)
if refresh:
self.refresh()
# 增加字符。start_x start_y表示开始的点。text是要增加的字符。
# refresh=True立即刷新，refresh=False不刷新。
# Add characters. Start_x Start_y indicates the starting point. Text is the character to be added
# Refresh =True Refresh immediately, refresh=False refresh not
def add_text(self, start_x, start_y, text, refresh=False):
if start_x > 128 or start_x < 0 or start_y < 0 or start_y > 32:
if self.__debug:
print("oled text: x, y input error!")
return
x = int(start_x + self.__x)
y = int(start_y + self.__top)
self.__draw.text((x, y), str(text), font=self.__font, fill=255)
if refresh:
self.refresh()
# 写入一行字符text。refresh=True立即刷新，refresh=False不刷新。
# line=[1, 4]
# Write a line of character text. Refresh =True Refresh immediately, refresh=False refresh not.
def add_line(self, text, line=1, refresh=False):
if line < 1 or line > 4:
if self.__debug:
print("oled line input error!")
return
y = int(8 * (line - 1))
self.add_text(0, y, text, refresh)
# 刷新OLED，显示内容
# Refresh the OLED to display the content
def refresh(self):
self.__oled.image(self.__image)
self.__oled.display()
# 读取CPU占用率
# Read the CPU usage rate
def getCPULoadRate(self, index):
count = 10
if index == 0:
f1 = os.popen("cat /proc/stat", 'r')
stat1 = f1.readline()
data_1 = []
for i in range(count):
data_1.append(int(stat1.split(' ')[i+2]))
self.__total_last = data_1[0]+data_1[1]+data_1[2]+data_1[3] + \
data_1[4]+data_1[5]+data_1[6]+data_1[7]+data_1[8]+data_1[9]
self.__idle_last = data_1[3]
elif index == 4:
f2 = os.popen("cat /proc/stat", 'r')
stat2 = f2.readline()
data_2 = []
for i in range(count):
data_2.append(int(stat2.split(' ')[i+2]))
total_now = data_2[0]+data_2[1]+data_2[2]+data_2[3] + \
data_2[4]+data_2[5]+data_2[6]+data_2[7]+data_2[8]+data_2[9]
idle_now = data_2[3]
total = int(total_now - self.__total_last)
idle = int(idle_now - self.__idle_last)
usage = int(total - idle)
usageRate = int(float(usage / total) * 100)
self.__str_CPU = "CPU:" + str(usageRate) + "%"
self.__total_last = 0
self.__idle_last = 0
return self.__str_CPU
# 读取系统时间
# Read system time
def getSystemTime(self):
cmd = "date +%H:%M:%S"
date_time = subprocess.check_output(cmd, shell=True)
str_Time = str(date_time).lstrip('b\'')
str_Time = str_Time.rstrip('\\n\'')
return str_Time
# 读取内存占用率 和 总内存
# Read the memory usage and total memory
def getUsagedRAM(self):
cmd = "free | awk 'NR==2{printf \"RAM:%2d%% -> %.1fGB \", 100*($2-$7)/$2, ($2/1048576.0)}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip('b\'')
str_FreeRam = str_FreeRam.rstrip('\'')
return str_FreeRam
# 读取空闲的内存 / 总内存
# Read free memory/total memory
def getFreeRAM(self):
cmd = "free -h | awk 'NR==2{printf \"RAM: %.1f/%.1fGB \", $7,$2}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip('b\'')
str_FreeRam = str_FreeRam.rstrip('\'')
return str_FreeRam
# 读取TF卡空间占用率 / TF卡总空间
# Read the TF card space usage/TOTAL TF card space
def getUsagedDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"SDC:%s -> %.1fGB\", $5, $2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip('b\'')
str_Disk = str_Disk.rstrip('\'')
return str_Disk
# 读取空闲的TF卡空间 / TF卡总空间
# Read the free TF card space/total TF card space
def getFreeDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"Disk:%.1f/%.1fGB\", $4,$2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip('b\'')
str_Disk = str_Disk.rstrip('\'')
return str_Disk
# 获取本机IP
# Read the local IP address
def getLocalIP(self):
ip = os.popen(
"/sbin/ifconfig enP8p1s0 | grep 'inet' | awk '{print $2}'").read()
ip = ip[0: ip.find('\n')]
if(ip == ''):
ip = os.popen(
"/sbin/ifconfig wlP1p1s0 | grep 'inet' | awk '{print $2}'").read()
ip = ip[0: ip.find('\n')]
if(ip == ''):
ip = 'x.x.x.x'
if len(ip) > 15:
ip = 'x.x.x.x'
return ip
# oled主要运行函数，在while循环里调用，可实现热插拔功能。
# Oled mainly runs functions that are called in a while loop and can be hot-pluggable
def main_program(self):
state = False
try:
cpu_index = 0
state = self.begin()
while state:
self.clear()
str_CPU = self.getCPULoadRate(cpu_index)
str_Time = self.getSystemTime()
if cpu_index == 0:
str_FreeRAM = self.getUsagedRAM()
str_Disk = self.getUsagedDisk()
str_IP = "IPA:" + self.getLocalIP()
self.add_text(0, 0, str_CPU)
self.add_text(50, 0, str_Time)
self.add_line(str_FreeRAM, 2)
self.add_line(str_Disk, 3)
self.add_line(str_IP, 4)
self.refresh()
cpu_index = cpu_index + 1
if cpu_index >= 5:
cpu_index = 0
time.sleep(.1)
except:
if self.__debug:
print("!!!---OLED refresh error---!!!")
pass
if __name__ == "__main__":
try:
oled = Juxi_OLED(i2c_num, debug=True)
while True:
oled.main_program()
time.sleep(2)
except KeyboardInterrupt:
oled.clear(True)
del oled
print(" Program closed! ")
pass7.创建虚拟环境
PowerShell
# 安装虚拟环境工具（如果未安装）sudo apt-get install -y python3-venv
# 创建虚拟环境
python3 -m venv oled_env
# 激活虚拟环境source oled_env/bin/activate # 激活后命令行前会显示 (oled_env)
# 在虚拟环境中安装依赖
# 使用阿里云镜像安装
pip install Adafruit_SSD1306 -i https://mirrors.aliyun.com/pypi/simple/
# 同时安装 pillow（依赖库）
pip install pillow -i https://mirrors.aliyun.com/pypi/simple/
# 运行代码（需在虚拟环境中）
# 进入到对应的simple文件夹下
cd /home/pi/oled-screen/luma.examples/examples
python3 oled_i2c.py # 默认总线 7
# 或指定总线（如总线 1）
python3 oled_i2c.py 1
#若提示权限错误，检查 sudo 配置或 I2C 设备权限