Tutorial de pantalla OLED secundaria para Raspberry Pi / Jetson
Serie Jetson
1. Diagrama de pines GPIO
Pruebe la comunicación I2C con el OLED de 0,91 pulgadas. Conéctelo de la siguiente manera:
Atención: no haga conexiones incorrectas ni provoque cortocircuitos en los pines: un error puede dañar el hardware de la placa base.
2. Prueba I2C
2.1. Instalar dependencias
PowerShell
sudo apt install -y python3-pip
sudo pip3 install smbus
sudo pip3 install Adafruit_SSD13062.2. Dispositivos I2C
Durante el desarrollo normal, debemos averiguar el bus y la dirección del dispositivo I2C.
(1) Consultar buses I2C
El siguiente comando enumera todos los buses del dispositivo:
PowerShell
i2cdetect -l(2) Consultar dispositivos I2C
El siguiente comando enumera los dispositivos I2C del bus especificado: la dirección I2C del OLED es 0x3c
PowerShell
i2cdetect -y -r *3. Ver la dirección IP y el puerto
Usar ifconfig para ver la dirección IP y el puerto
Modificar el código según el puerto real
4. Resultado del experimento
Crear el archivo Oled_i2c.py
PowerShell
# (If gedit is not installed) sudo apt install gedit
sudo gedit Oled_i2c.pyCopiar el siguiente código, pegarlo en el archivo, guardar y cerrar
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! ")
passAl iniciar el programa, el OLED muestra información del sistema como uso de CPU, hora del sistema y uso de memoria:
Raspberry Pi, Orange Pi
1. Activar la opción I2C
Entrar en la configuración del sistema Raspberry Pi, elegir: Preferencias → Raspberry Pi Configuration → Interfaces → encontrar la opción I2C y activarla; luego el sistema se reiniciará. (ver figura abajo)
En modo de comandos, sudo raspi-config también permite encontrar esa opción, activar I2C y reiniciar el sistema.
2. Instalar la biblioteca I2C
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-venvAquí usamos Python3. Tras instalar la biblioteca I2C, usar i2cdetect para comprobar si el módulo de pantalla es reconocido
PowerShell
i2cdetect -y 1Se muestra que el dispositivo fue detectado en la dirección «0x3c» (ver abajo). La dirección por defecto de este tipo de dispositivo es hexadecimal.
3. Configurar el archivo de fuente
El código usa la fuente DejaVuSansMono.ttf:
PowerShell
sudo apt-get install -y fonts-dejavu-coreO modificar el código a una fuente ya existente en el sistema (por ejemplo, ImageFont.load_default())
4. Configurar permisos
Asegurarse de que los permisos de los archivos de dispositivos I2C sean correctos:
PowerShell
sudo chmod a+rw /dev/i2c-* # Temporary; for permanent effect, configure udev rules5. Ver la dirección IP y el puerto
Usar ifconfig para ver la dirección IP y el puerto reales
PowerShell
# (If net-tools is not installed) sudo apt install net-tools
ifconfigModificar las dos zonas marcadas en el código según el puerto real
6. Crear el archivo Oled_i2c.py
Crear el archivo Oled_i2c.py en el directorio Home
PowerShell
# (If gedit is not installed) sudo apt install gedit
sudo gedit Oled_i2c.pyCopiar el siguiente código, pegarlo en el archivo, guardar y cerrar
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. Crear un entorno virtual
PowerShell
# Install virtualenv tool (if not installed) sudo apt-get install -y python3-venv
# Create a virtual environment
python3 -m venv oled_env
# Activate:source oled_env/bin/activate # After activation, (oled_env) appears at the command prompt
# Install dependencies in the virtual environment
# Use the Aliyun mirror
pip install Adafruit_SSD1306 -i https://mirrors.aliyun.com/pypi/simple/
# Also install pillow (dependency)
pip install pillow -i https://mirrors.aliyun.com/pypi/simple/
# Run the code (must be inside the virtual environment)
# Go to the corresponding simple folder
cd /home/pi/oled-screen/luma.examples/examples
python3 oled_i2c.py # default bus 7
# Or specify a bus (e.g. bus 1)
python3 oled_i2c.py 1
# If a permission error occurs, check the sudo configuration or I2C device permissionsEjemplo del repositorio oficial
JUXI proporciona código de driver open source para pantallas OLED: GitHub
Ejemplo de driver I2C
bash
sudo apt install -y python3-pip
sudo pip3 install smbus Adafruit_SSD1306python
import Adafruit_SSD1306
from PIL import Image, ImageDraw, ImageFont
# 初始化 OLED (128x32)
disp = Adafruit_SSD1306.SSD1306_128_32(rst=None)
disp.begin()
disp.clear()
disp.display()
# 绘制文字
image = Image.new('1', (disp.width, disp.height))
draw = ImageDraw.Draw(image)
draw.text((0, 0), 'Hello Juxi!', font=ImageFont.load_default(), fill=255)
disp.image(image)
disp.display()