0.91" OLED Screen
Jetson Series Main Controller
1. GPIO Pin Diagram
Use a 0.91-inch OLED to test the I2C communication function, and connect according to the following wiring:
Caution: Do not connect incorrectly or cause pin short circuits, as mistakes may lead to damage to the main board hardware!
2. I2C Test
2.1. Install Dependencies
PowerShell
sudo apt install -y python3-pip
sudo pip3 install smbus
sudo pip3 install Adafruit_SSD1306
2.2, I2C Device
During normal development, we need to find the device bus and device address where the I2C device is mounted.
(1) Query the I2C bus
Entering the following command at the end point can list all buses of the device:
PowerShell
i2cdetect -l(2) Query I2C device
Entering the following command at the end point can list the I2C devices under the specified bus: the I2C address corresponding to oled is 0x3c
PowerShell
i2cdetect -y -r *
4. Check IP address and port
Use ifconfig to view IP address and port
Change the code according to the actual port
3. Experimental Effect
Create the Oled_i2c.py file
PowerShell
sudo gedit Oled_i2c.pyCopy and paste the following code
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---")
# 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.__i2c_bus == 1:
# self.__i2c_bus = 8
# elif self.__i2c_bus == 8:
# self.__i2c_bus = 1
if self.__debug:
print("---OLED no found!---")
return False
# 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()
# 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()
# 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)
# Refresh the OLED to display the content
def refresh(self):
self.__oled.image(self.__image)
self.__oled.display()
# 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
# if self.__debug:
# print(self.__str_CPU)
return self.__str_CPU
# 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'")
# print(date_time)
return str_Time
# 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
# Read free memory/total memory
def getFreeRAM(self):
cmd = "free -h | awk 'NR==2{printf \"RAM: %.1f/%.1fGB \", $7,$2}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip("b'")
str_FreeRam = str_FreeRam.rstrip("'")
return str_FreeRam
# Read the TF card space usage/TOTAL TF card space
def getUsagedDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"SDC:%s -> %.1fGB\", $5, $2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip("b'")
str_Disk = str_Disk.rstrip("'")
return str_Disk
# Read the free TF card space/total TF card space
def getFreeDisk(self):
cmd = "df -h | awk '$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
# 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 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)
# Display image.
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! ")
passAfter starting the program, the OLED will display system information such as system CPU usage, system time, and memory usage:
Raspberry Pi, Orange Pi
1. Turn on the I2C option
Enter the Raspberry Pi system settings, select: Preferences → Raspberry Pi Configuration → Interfaces → Find the I2C option and turn it on, then the system will restart automatically. (Refer to the figure below)
If you are in command mode, you can enter sudo raspi-config to still find the option to enable I2C and then restart the system.
2. Install the I2C library files
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-venvI am using Python3 . After installing the I2C library, use the i2cdetect command to check if the display module is recognized
PowerShell
i2cdetect -y 1Indicates that the device has been detected at address "0x3c" (as shown below). The default for this type of device is a hexadecimal address.
3. Font File Configuration
The code uses DejaVuSansMono.ttf font:
PowerShell
sudo apt-get install -y fonts-dejavu-coreor modify the code to use a font already available in the system (such as ImageFont.load_default ())
4. Permission Configuration
Ensure that the I2C device file permissions are correct:
PowerShell
sudo chmod a+rw /dev/i2c-* # Temporary effect, permanent effect requires configuration of udev rules5. Check IP address and port
Use ifconfig to view the actual IP address and port
PowerShell
# (if net-tools is not installed) sudo apt install net-tools
ifconfig
Change the contents of the following two boxed areas in the code according to the actual port
6. Create the Oled_i2c.py file
Create the Oled_i2c.py file in the Home directory
PowerShell
# (if gedit is not installed) sudo apt install gedit
sudo gedit Oled_i2c.pyCopy the following code, paste it into the file, save, and close
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---")
# Initialize OLED, return True on success, False on failure
# 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.__i2c_bus == 1:
# self.__i2c_bus = 8
# elif self.__i2c_bus == 8:
# self.__i2c_bus = 1
if self.__debug:
print("---OLED no found!---")
return False
# Clear the display. refresh=True refreshes immediately, refresh=False does not refresh
# 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()
# Add characters. start_x and start_y indicate the starting point; text is the character to be added
# refresh=True refreshes immediately, refresh=False does not refresh
# 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()
# Write a line of character text. refresh=True refreshes immediately, refresh=False does not refresh
# 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)
# Refresh the OLED to display the content
# Refresh the OLED to display the content
def refresh(self):
self.__oled.image(self.__image)
self.__oled.display()
# Read the CPU usage rate
# 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
# if self.__debug:
# print(self.__str_CPU)
return self.__str_CPU
# Read system time
# 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'")
# print(date_time)
return str_Time
# Read the memory usage and total memory
# 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
# Read free memory/total memory
# Read free memory/total memory
def getFreeRAM(self):
cmd = "free -h | awk 'NR==2{printf \"RAM: %.1f/%.1fGB \", $7,$2}'"
FreeRam = subprocess.check_output(cmd, shell=True)
str_FreeRam = str(FreeRam).lstrip("b'")
str_FreeRam = str_FreeRam.rstrip("'")
return str_FreeRam
# Read the TF card space usage/total TF card space
# Read the TF card space usage/TOTAL TF card space
def getUsagedDisk(self):
cmd = "df -h | awk '$NF==\"/\"{printf \"SDC:%s -> %.1fGB\", $5, $2}'"
Disk = subprocess.check_output(cmd, shell=True)
str_Disk = str(Disk).lstrip("b'")
str_Disk = str_Disk.rstrip("'")
return str_Disk
# Read the free TF card space/total TF card space
# Read the free TF card space/total TF card space
def getFreeDisk(self):
cmd = "df -h | awk '$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
# Read the local IP address
# 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 main function; call it in a while loop to support hot-plugging
# 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)
# Display image.
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. Create a virtual environment
PowerShell
# Install the virtual environment tool (if not installed) sudo apt-get install -y python3-venv
# Create a virtual environment
python3 -m venv oled_env
# Activate the virtual environment: source oled_env/bin/activate (after activation, (oled_env) is shown before the command prompt); install dependencies in the virtual environment
# Install using the Alibaba Cloud mirror
pip install Adafruit_SSD1306 -i https://mirrors.aliyun.com/pypi/simple/
# Also install pillow (dependency library)
pip install pillow -i https://mirrors.aliyun.com/pypi/simple/
# Run the code (must be inside the virtual environment)
# Enter the corresponding simple folder
cd /home/pi/oled-screen/luma.examples/examples
python3 oled_i2c.py # Default bus 7
# Or specify the bus (e.g., bus 1)
python3 oled_i2c.py 1
#If a permission error appears, check the sudo configuration or the I2C device permissions
Official Repository Example
Juxi Technology provides open-source driver code for the OLED screen: GitHub
I2C Driver Example
bash
sudo apt install -y python3-pip
sudo pip3 install smbus Adafruit_SSD1306python
import Adafruit_SSD1306
from PIL import Image, ImageDraw, ImageFont
# Initialize OLED (128x32)
disp = Adafruit_SSD1306.SSD1306_128_32(rst=None)
disp.begin()
disp.clear()
disp.display()
# Draw text
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()