MacGyver IT: w/raspberry Pi 3 Kevin Capwell META Pat Zielke Viroqua

Transcription

1 Kevin Capwell META Pat Zielke Viroqua DISCLAIMER: The open-source software discussed is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non-infringement In no event shall the instructors, authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software. 1 What are the Prerequisites of this Session? Familiarity with the basics of Linux. Being comfortable with CLI. Basic concept of networking technology. Using SMTP for transmission. An area that requires climate monitoring. The need to communicate via digital sign. A thirst for knowledge.

2 Open your John Adams' Boon Boxes! Open your Raspberry Pi 3 Model B Deep Dive on the Raspberry Pi 3

3 Why Install Heatsinks on the RPi 3? 2 The RPi 3's SoC (system on a chip, or CPU) can hit 100 C! That's hot enough to boil water! Not all environments are "ideal". Essential for overclocking the RPi. Helps prevent RPi self throttling. 3M thermal transfer tape just peel and stick. Increase the surface area of SoC by 10 times. RPi with Heatsinks Installed RPi Under load with Thermal Imaging

4 Why DIY Environmental Monitoring? 3 Raspberry Pi 3b - with case ~ $50.00 DS18B20 Digital Temp Probe - 2M $2.50 (1-wire circuit max: 75, length + 3.3v) 4.7k Ohm Resistor ~ $0.25 Qty:3 22cm Solderless Jumper Wires ~ $0.45 Wire Barrier Block ~ $1.40 Software $ all Open-Source! Total: $ Time to "Burn" Raspbian to your microsd Inserting the microsd into the RPi 3

5 NOOBS vs Raspbian 4 NOOBS = New Out Of the Box Software Install a range of OS Live CD Raspbian is the "official" OS of RPi Raspbian is based on Debian distro Release date: Raspbian Stretch Connect the Peripherals to the RPi 3 Parts to Build Your Temp Monitor

6 Temperature Probe Connected to the RPi 3 5 Use the cutter tool to strip 1.5"-2" off of the DS18B20 Red = pin1 3.3v Yellow = pin7 comms Black = pin6 ground Resistor on jumper between pin 1+7 What is Open Source Software? Contributory Software to this Project 6 Apache Apache is the most commonly used Web server on Linux systems. Multi router traffic grapher 2.17 MRTG is a tool to monitor the traffic load on network links.

7 Why? $ Booting the Raspberry Pi 3 Connect the 2.5A power adaptor to the Raspberry Pi 3. After the startup is complete, you will see a Desktop. Go to the RaspMenu upper left > Preferences > Raspberry Pi Config

8 Configuring the Raspberry Pi 3 7 Jump to the Localization tab {Click the OK button after each modification} Locale Lang:en, Co:US Timezone Area:America, Loc:Chicago Key Co:United States, Var:English(US) WiFi Co Code Co:US United States Click on the Interface tab Configuring the Raspberry Pi 3 8 Click on the Interface tab SSH Change to Enable VNC Change to Enable Example: ssh -l pi <ipaddr.of.rpi3> Configuration Click on OK button Select No when you are prompted for a reboot Before we Begin, Here are Some Linux Basics 9 Get help: man <cmd> or <cmd> -h Linux Info: Prompts are important - # vs $ Type: cat /etc/*release* The tab key is your friend The up and down arrows are your friend Capitalization counts Run process in background add & at the end Tail <filename> will give you the last 10 lines

9 Configuring the Raspberry Pi 3 Click the terminal icon on the menu bar. At the $ prompt type: sudo raspi-config Configuring the Raspberry Pi 3 Configuring the Raspberry Pi 3 10 Selecting options from the raspi-config app From the menu select 5. Interfacing Options Select P7 1-wire. Enable 1-wire interface <Yes> <OK> From the menu select 7. Advanced Options Select A1 Expand Filesystem <OK> Select <Finish> Reboot now <Yes> After the reboot, notice the warning about SSH

10 Configuring the Raspberry Pi 3 Return to RPi Config Go to the System tab Change password Change hostname Boot to Desktop Wait for network Click the OK button Configuring the Raspberry Pi 3 This is the top right of the menu bar This section has a few important selections RealVNC configures VNC remote access Bluetooth enables/disables + configuration WiFi enable/disable + select SSID Volume control Task Manager Date + Time Eject a volume Reboot now APT Commands 11 APT (the Advanced Packaging Tool) is a rapid, practical, and efficient way to install packages. Open Terminal apt vs apt-get [answer "Y" to all prompts] sudo apt purge wolfram-engine [streamlined] sudo apt update sudo apt upgrade sudo apt dist-upgrade sudo apt list --installed sudo apt install <pkg> Reboot now

11 APT Commands 12 After the reboot, customized files have been placed in the ~/oldconfiles directory. Right click Desktop > Desktop Preferences > Defaults > For Large Screens {OK} Open Terminal sudo apt remove/purge <pkg> sudo apt-cache search/policy <keywd pkg> sudo apt autoremove sudo rpi-update Basic System Commands 13 df -h [free space] cat /proc/cpuinfo [processor info] cat /proc/meminfo [memory info] top [show top processes and memory] ls -al [list all files] pwd [print working dir] mkdir myfold chmod 777 myfold ls -al my* rm -fr myfold/ ls -al my* <error> runlevel (3=cli, 5=gui) Enough Basics! Let's Install Some Services 14 sudo apt install apache2 sudo apt install mrtg (read by root > Yes) sudo mkdir /var/www/mrtg cat /boot/config.txt (last: dtoverlay=w1-gpio) cd /sys/bus/w1/devices ls 28* (last file: w1_slave) cat 28*/w1_slave Line 1 ends in YES Line 2 ends w/t=##### cd ~ (this command takes you back "home")

12 Basic Systemd Commands with Examples 15 sudo service apache2 stop sudo service apache2 start sudo service apache2 status sudo systemctl enable/disable <service> sudo systemctl list-unit-files --type=service grep enabled Where is mrtg? sudo cat /etc/rc.local sudo cat /etc/cron.d/mrtg Acquiring the Support Files for the RPi 3 Return to the PIXEL Desktop (which stands for Pi Improved Xwindow Environment, Lightweight ) Enter URL: my.sharepoint.com/:u:/p/kcapwell/eqlvoedzn yhhvob3kxohfbabhb2k3g6w0hrwm2plvfaqrg

13 Distributing the Support Files for the RPi 3 17 ls -al (you should see six files) sudo cp get_temp.py /usr/local/bin sudo cp check_temp.sh /usr/local/bin sudo chmod -R 777 /usr/local/bin sudo chmod -R 777 /usr/local/src sudo chmod -R 777 /var/www/mrtg echo "0" > /usr/local/src/temp_alert_status ls -al /var/www/mrtg Testing the Support Files for the RPi 3 18 Type: get_temp.py Type: check_temp.sh sudo mv /etc/mrtg.cfg /etc/mrtg.old sudo cp mrtg.cfg /etc/mrtg.cfg sudo indexmaker /etc/mrtg.cfg > /var/www/mrtg/index.html ls -al /var/www/mrtg About VI

14 About VI Hmm, Where's the App? About Nano Editing the Support Files for the RPi 3 19 sudo nano /etc/mrtg.cfg (Cont+X when done) sudo nano /usr/local/bin/check_temp.sh sudo nano /etc/apache2/sites-available/000- default.conf {DocumentRoot /var/www/mrtg} sudo service apache2 restart Return to Chromium Press Cont+H Select Clear Browsing Data New Tab Enter localhost in the URL bar

15 Adding Threshold Alerts to your RPi 3 20 Return to the Terminal ($ pwd {tempfiles}) sudo apt install ssmtp sudo apt install mailutils sudo mv /etc/ssmtp/ssmtp.conf ~/Documents sudo mv /etc/ssmtp/revaliases ~/Documents sudo cp ssmtp.conf /etc/ssmtp sudo cp revaliases /etc/ssmtp Editing the Threshold Alerts for the RPi 3 21 sudo nano /etc/ssmtp/ssmtp.conf sudo nano /etc/ssmtp/revaliases nano msg.txt ssmtp user1@example.edu < msg.txt (fix ) sudo crontab -e (stick with nano) * * * * * /usr/local/bin/check_temp.sh cat /var/log/syslog grep check_temp.sh Date + Time /usr/local/bin/check_temp.sh Temperature Monitoring the Results

16 Temperature Monitoring the Results Temperature Monitoring the Results Pat's Awesome Stuff Goes Here

17 Did Someone Mention a Surprise?!?? Questions? Kevin Capwell Midwest Educational Technology Association kcapwell@brainstormk20.com Pat Zielke Viroqua School District pzielke@viroqua.k12.wi.us