ESPe71 / rpi-monitor

Monitoring an Raspberry Pi with an OLED

RPi-Monitor

Monitoring an Raspberry Pi with an OLED

You can buy an OLED for example on Amazon.

Requirements

Make sure the I2C-Interface is activated.
You can use the tool raspi-config-->Interface Options-->I2C.

You need following installations:

• sudo apt-get install i2c-tools
• sudo apt-get install python3-pip
• sudo pip3 install adafruit-circuitpython-ssd1306
• sudo apt-get install python3-pil
• sudo apt-get install ttf-dejavu

You can determine the address of the i2c wire interface with the following command:
i2cdetect -y 1

Wiring the OLED to the Rasperry Pi

OLED	Pi
Gnd	Gnd
VCC	3.3V
SDA	SDA (Pin 3)
SCL	SCL (Pin 5)

Setup

In file stats.py check what information you want to display.

You can it run locally with:
./stats.py or
phyton3 stats.py

Start at system startup

Add in /etc/rc.local the following line:

sudo python3 /home/pi/rpi-monitor/stats.py &

Using another I2C-Bus as Bus 1 on Raspberry Pi 4

First have a look in /boot/overlays/README. Here you can look for Name i2c1, i2c2, i2c3, i2c4, i2c5 or i2c6.

In the /boot/config.txt add an entry for your choosen i2c-Bus.

#Name:   i2c4
#Info:   Enable the i2c4 bus. BCM2711 only.
#Load:   dtoverlay=i2c4,<param>
#Params: pins_6_7                Use GPIOs 6 and 7
#        pins_8_9                Use GPIOs 8 and 9 (default)
#        baudrate                Set the baudrate for the interface (default
#                                "100000")
dtoverlay=i2c4,pins_8_9

Now wire your display as follows (here e.g. for bus 4):

OLED	Pi
Gnd	Gnd
VCC	3.3V
SDA	GPIO 8 (Pin 24)
SCL	GPIO 9 (Pin 21)

Reboot your pi and test the i2c-bus (e.g. bus 4):

i2cdetect -y 4

You need to install adafruit-extended-bus

sudo pip3 install adafruit-extended-bus

In your python-script change the creation of the I2C as follows:

import adafruit_ssd1306
from adafruit_extended_bus import ExtendedI2C as i2c

DISPLAY_WIDTH  = 128
DISPLAY_HEIGHT = 64

...
...

I2C            = i2c(4)
DISPLAY        = adafruit_ssd1306.SSD1306_I2C(DISPLAY_WIDTH, DISPLAY_HEIGHT, I2C)

References

• https://learn.adafruit.com/adafruit-pioled-128x32-mini-oled-for-raspberry-pi/usage
• https://indibit.de/raspberry-pi-oled-display-128x64-mit-python-ansteuern-i2c/
• https://circuitpython.readthedocs.io/projects/extended_bus/en/latest/
• https://keytosmart.com/single-board-computers/raspberry-pi-4-gpio-pinout/