Raspberry Pi

• User : pi
• Pass : raspberry

$ sudo raspi-config

Go to Interface Options then SSH and activate it. No reboot is required.

It is good practice to have your router assign a static IP address to a RPi if you want to regularly connect to it via ssh

$ sudo raspi-config

Go to Interface Options then Camera and activate it. Raspi-config will propose a reboot which should be accepted.

Navigate to a folder where you want the script to be located.

$ touch camera.py

Edit this file and copy the following :

#!/usr/bin/env python
 
from picamera import PiCamera
from time import sleep
 
camera = PiCamera()
camera.start_preview()
sleep(5)
camera.capture('/home/pi/Desktop/picture.jpg')
camera.stop_preview()

Warning, this will save to user pi's desktop, remember to change username if you aren't using user pi

Run the script once.

You can view the picture by either copying it to another machine with scp or by using a screen and mouse/keyboard on the pi itself.

Modify the /etc/rc.local file (requires sudo)

$ sudo nano /etc/rc.local

Before the 'exit 0' line at the end insert lines like this one :

bash /path/to/script.sh

$ cat /sys/class/thermal/thermal_zone0/temp

Divide by 1000 to get °C format

$ vcgencmd measure_temp
$ /opt/vc/bin/vcgencmd measure_temp (Full Path)

These measures were done on a Rapsberry Pi 4 running Raspbian with no heavy-duty program running, no screen or USB devices attached and at a room temperature around 20°C

• With a 5V fan connected to 5V the temperature is stable around 35-38°C. Fan is loud and disturbing
• With a 5V fan connected to 3.3V the temperature is stable around 41-42°C
• With no fan connected the temperature is stable around 55-58°C

GPIO Header

# Exports pin to userspace
$ echo "18" > /sys/class/gpio/export                  
 
# Sets pin 18 as an output
$ echo "out" > /sys/class/gpio/gpio18/direction
 
# Sets pin 18 to high
$ echo "1" > /sys/class/gpio/gpio18/value
 
# Sets pin 18 to low
$ echo "0" > /sys/class/gpio/gpio18/value 
 
# Exports pin to userspace
$ echo "4" > /sys/class/gpio/export
 
# Sets pin 4 as an input
echo "in" > /sys/class/gpio/gpio4/direction
 
# Read value of pin 4
cat /sys/class/gpio/gpio4/value