Raspberry Pi programs and setup

Some of these instructions are obsolete
They were written for Rasbian Wheezy, and I'm now using Jessie on the Pi v2

💥 How to set up your Raspberry Pi

Install Rasbian

• You should have a preinstalled SD card. If you don't then download NOOBs offline and unzip it onto the SD Card you want to use
• Power on your Raspberry PI (after you've plugged in HDMI cable, keyboard, SD card, WiFi USB adapter)
• At the installation option screen, first make sure that you set your language and keyboard to US and not UK or GB.
• Choose the Raspbian option by hitting the spacebar to select "Raspbian" and then press i to start the installation (it will take 15 minutes to complete).
• the default username and password is "pi" and "raspberry", respectively
• once installed the system will reboot
• login with the default credentials
• you are now logged into the shell. Use startx to launch the desktop if you want to.

Keyboard Problems

If you press the ~ key and see that it is not ~ that means your keyboard is not setup properly.

• run sudo raspi-config from the command line
• if you don't have a mouse plugged in, use the key and arrow keys to navigate.
• highlight 4 Internationalisation Options and press enter
• You can also set your timezone here.
• you should see an option for keyboard layout, select that
• you should change to a Generic Key keyboard when in doubt
• the next pages will let you set a locale for the keyboard, we want US not UK (or en_US.UTF-8)
• Choose other in the language choice
• Choose US for the next choice (or en_US.UTF-8)
• you can leave everything else default and just press enter throughout
• you make need to click no to exit.

Setup WiFi

• In the past, the wifi was setup by changing /etc/network/interfaces. If you need the old commands, look at the other branch of this repository.
• The new method of setting up wifi involves the following:
• Open the wpa-supplicant configuration file in nano: sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
• Go to the bottom of the file and add the following:

network={
    ssid="your_network_SSID"
    psk="Your_wifi_password"
}

• if you don't want your passphrase visible, you can encrypt it: wpa_passphrase mySSID Copy and paste the output from this into the wpa_supplicant.conf file

• save the file with ctrl+o, press to confirm the filename, and press ctrl+x to close nano.

• restart the RPi with sudo shutdown -r now or <CTRL><ALT><DEL>.

• Instead of restarting, the following often work: sudo ifdown wlan0 then sudo ifup wlan0

• To confirm that you're connected to the internet, type date. Raspberry Pi will automatically set the date and time to the correct value from the internet. Or you can ping Google: ping 8.8.8.8

• To find your IP address, type ifconfig .

• Be careful not to make typos or you won't be able to connect to the internet.

Fix screen resolution

Sometimes, unpredictably, the Raspberry Pi starts with a really huge screen resolution. The way to fix it is to do the following: sudo nano /boot/config.txt and then uncomment/add in the following two lines:

hdmi_group=1
hdmi_mode=16

💣 Hmm... this seems to have stopped working. Try the following or look at https://elinux.org/RPiconfig#Video_mode_options

hdmi_group=2
hdmi_mode=8

Update Linux

• Update the list of packages (repositories) with sudo apt-get update
• Upgrade the RPi with sudo apt-get upgrade
• You can combine this into one command: sudo apt-get update && sudo apt-get upgrade
• You must be connected to the internet for this to work
• You should do this every month or so to apply the most recent patches to the operating system.
• Extra programs that I tend to install on Linux: sudo apt-get vim vim-doc byobu htop mc bmon

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💥 Here are Useful Linux Commands for GUI and command line (read these at some point).

🔷 raspi-config

sudo raspi-config will let you change many many of the settings of your raspberry pi.

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💥 Various Tools

🔷 GitHub and Git

How to use GitHub This is my attempt to understand and explain it. You only need to run one command to download my programs: git clone https://github.com/salamander2/RaspberryPi

🔷 Connecting and File Transfer

ssh is a command that lets you make a secure encrypted connection from one computer to another (on Linux or Mac). For Windows, you have to download a program "PuTTY" and use that. There are also handy versions for Android (e.g. JuiceSSH).

🔷 File Transfer

A companion program to ssh, scp, is used to copy files from one computer to another. e.g. in my music folder, I can open a terminal window and type scp Beatles*mp3 [email protected]:/home/pi/music to copy all of my Beatles songs over. Other ways of moving files:

• set up a shared (SMB or Samba) folder
• use Dropbox or the cloud
• plug a USB drive into your Raspberry Pi
• plug your Raspbian SD card into your computer. Unfortunately, Windows doesn't know how to read the Ext4 file system - so you need to install software (ext2read) that will let Windows do this.
• rsync (a linux program that is similar to ssh/scp)

🔷 Music

omxplayer : this runs the default music player. If you're interested in music on your RPi, have a look at http://www.raspberrypi.org/tag/music/ and http://www.raspyfi.com/

NOTE: you need at least 64 MB of ram allocated for GPU in order to play mp3s. To change this type sudo raspi-config and choose "advanced options" [This may be old information]

omxplayer -o local Beatles.mp3 This will play the mp3 over the Audio output. To make sound go over the HDMI output, put hdmi (or HDMI?)

[other sound related commmands: alsamixer sudo aplay /usr/share/sounds/alsa/Front_Center.wav amixer cset numid=3 0]

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💥 Programs

I have put all of my Raspberry Pi programs with photos, schematics, videos, explanations, and source code in separate folders under RaspberryPi/programs

🔷 Running programs

• To run a python program from the command line, type python stuff.py where stuff.py is the name of your program (in the current directory).
• If your Python program starts with the line #!/usr/bin/env python then Linux knows that it is a Python program and you can just type ./stuff.py (oh, wait, you have to make it executable first by typing chmod u+x stuff.py )
• Any program (in any language) that uses the GPIO pins has to be run using the "sudo" command. e.g. sudo python stuff.py . Note that this does not apply to the LCD program since it is using the GPIO pins in the I2C mode. But ... then I changed the program to use some other GPIO pins to detect a switch press.

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💥 Useful references for GPIO pins

🔷 Note that the GPIO pins have internal pull-up and pull-down resistors. These normally default to OFF. However, you can easily set them in Python (which I do in my programs) and then you don't have to use external pull-up or pull-down resistors when you connect a switch. See this page with it's very handy diagrams to compare the two situations.

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• GPIO P1 Header Pinouts: http://elinux.org/Rpi_Low-level_peripherals#P1_header

• More details for pinouts: http://elinux.org/RPi_BCM2835_GPIOs