Set up a Raspberry Pi Zero headless

If you are using the GUI (Raspian full download) and want to connect your RPi Zero to a keyboard and monitor there are probably easier ways to do this. These notes are for people that want to use a headless (no monitor and GUI) setup ready to connect to your RPi after first boot via SSH from another terminal.

Download Raspbian Lite

wget -O raspbian-lite-latest.zip https://downloads.raspberrypi.org/raspbian_lite_latest

Download link: https://www.raspberrypi.org/downloads/raspbian/

Write Image to SD Card

dd bs=4M if=2017-08-16-raspbian-stretch-lite.img of=/dev/sdb

After this step there should be 2 additional mounts (if not mount the 2 SD card partitions manually).

Set up network interfaces

Create a new config file for the wireless interface.

cd etc/network/interfaces.d/
vim wlan0.conf

Add the following to the new file (if you want to use DHCP – change to static if you want to fix the IP):

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Set up connection details for local wireless network

vim etc/wpa_supplicant/wpa_supplicant.conf

Check the file and ensure the network settings are as per the Wireless Network you are connecting to.

country=AU
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="SSID"
psk=HASHED_PSK_VALUE
}

You could use the clear-text PSK passphrase but I prefer not to do that in configuration files. Create a PSK hash using ‘wpa_passphrasethis older article

There could be other config values you might need depending on the network you are connecting to. More info: https://linux.die.net/man/5/wpa_supplicant.conf.

Ensure there are DNS Servers configured

sudo vim etc/resolv.conf

Add the following to the new file (or your own nameservers):

# Google's public DNS servers
nameserver 8.8.8.8
nameserver 8.8.4.4

Enable SSH Access

Create an ssh empty file in the mounted boot partition. This is necessary to enable SSH access as SSH is by default disabled on more recent versions of Raspbian.

cd boot/
sudo touch ssh

Boot RPi

Boot the Rpi by powering up and after ~30secs you should be able to connect to the IP assigned. Check your router or ise ‘nmap’ or similar to check the assigned IP:

sudo nmap -p22 -sV 10.1.1.0/24

Default login details are
UID: pi
PWD: rasbperry

My normal further setup steps for RPi 3 are here.

EDIT [2017-08-21]: One of the things necessary on later RPi’s is to turn off power saving mode on the WLAN interface.

sudo iw dev wlan0 set power_save off

RaspberryPi Version 3 SOE

Since there is now a supported Raspbian version without GUI and other unneeded add-ons available as Raspbian Lite the need to use other installers (with sometimes some downsides) is now not a necessity anymore. Below is a list of steps I like to perform before using them for any purpose as my Standard Operating Environment.

Download Raspbian Lite

Download link: https://www.raspberrypi.org/downloads/raspbian/

Write to SD Card

dd bs=4M if=2016-05-27-raspbian-jessie-lite.img of=/dev/sdb

Boot RPi

Default login details are
UID: pi
PWD: rasbperry

Regional settings

locale-gen en_AU.UTF-8
dpkg-reconfigure locales
ln -sf /usr/share/zoneinfo/Australia/Adelaide /etc/localtime

System update

apt update && apt upgrade
apt install vim

Setup SSH keys

As a security precausion it’s a good idea to disable password authentications
ssh-keygen -t rsa
vim /root/.ssh/authorized_keys
# --> add RSA public key

Setup Wireless LAN

iwlist wlan0 scan
wpa_passphrase SSID WPA_KEY
vim /etc/wpa_supplicant/wpa_supplicant.conf

Copy the resulting hash from the previous command

Example config

country=AU
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="YOURSSID"
psk=123456789012345678901234567890
}

Rename default user account

The default Raspbian images use the default user ‘pi’ – I prefer to change this user to another account for security purposes and to be in line with other Linux system I use.

Reboot and log in to the RPi as root – you need to run the following commands as root.

usermod -l NEW_USER_ID pi
usermod -m -d /home/NEW_USER_ID NEW_USER_ID
groupmod --new-name NEW_USER_ID pi
mkdir /home/NEW_USER_ID/.ssh/
vim /home/NEW_USER_ID/.ssh/authorized_keys
# --> add RSA public key
# change owner and permissions on key files
chown -R NEW_USER_ID:NEW_USER_ID /home/NEW_USER_ID/.ssh/
chmod 700 /home/NEW_USER_ID/.ssh/
chmod 600 /home/NEW_USER_ID/.ssh/authorized_keys
rm /etc/sudoers.d/010_pi-nopasswd
echo 'NEW_USER_ID ALL=(ALL) NOPASSWD: ALL' > /etc/sudoers.d/010_NEW_USER_ID-nopasswd

If you are using the desktop version not a headless version you want to make sure you don’t boot into the desktop and if you want to change the autologin ensure you update the username there as well.

/etc/systemd/system/autologin@.service
/etc/lightdm/lightdm.conf

Configure Raspberry Pi settings

raspi-config
I generally need to enable SPI, change the hostname and others depending on the purpose of the unit.

EDIT [2017-08-21]: With the update of Raspbian to Stretch you now have the firmware updater as part of the Raspbian repos:

sudo rpi-update

This will update the Pi Firmware to the latest version as well – which is worth it if you use it for later cameras and peripheral usage.

EDIT [2017-12-27]: change annoying vim defaults in Debian Stretch onwards. Visual mode.

sudo vim /usr/share/vim/vim80/defaults.vim

Comment out the following lines:
“if has(‘mouse’)
” set mouse=a
“endif

FreedomBox + RaspberryPi = FreedomPi

I have been watching progress on FreedomBox ever since watching a video of Eben Moglen a few years ago.

Turns out that that they recently announced the availability of their 0.1 preview release. As part of this there is one component that is extremely useful for RaspberryPi users (funnily the co-founder of RasperryPi is also called Eblen by first name – go figure) out there concerned about increasing snooping of private information by governments and corporations for a variety of reasons.

Meet ‘freedombox-privoxy’

freedombox logo

https://www.gitorious.org/freedombox-privoxy/freedombox-privoxy

This software combines the functionality of the Adblock Plus ad blocker, the Easy Privacy filtering list, and the (HTTPS Everywhere](https://www.eff.org/https-everywhere) website redirection plugin into a single piece of software to run on your FreedomBox. Combining these different plugins into software for your FreedomBox means that you can use them with almost any browser or mobile device using a standard web proxy connection.

Best of all this has already been made available via the Raspbian repositories (http://mirrordirector.raspbian.org/raspbian/pool/contrib/f/freedombox-privoxy/) so the install is extremely simple.

sudo apt-get install freedombox-privoxy

Note: make sure that you have the ‘contrib’ branch in the Raspbian repositories enabled in /etc/apt/sources.list

deb http://mirrordirector.raspbian.org/raspbian wheezy main contrib non-free
deb-src http://mirrordirector.raspbian.org/raspbian wheezy main contrib non-free

Kudos to James Vasile for the technical work !

To get some more idea on the usage of privoxy you can check this article.

Enabling the watchdog timer on the Raspberry Pi

Turns out that the Broadcom BCM2708 chip on the RPi has a hardware watchdog. This can be very useful if your RPi is located remotely and locks up. However, this would not the preferred method of restarting the unit and in extreme cases this can result in file-system damage that could prevent the RPi from booting. If this occurs regularly you better find the root cause of the problem rather than fight the symptoms.

Enable Watchdog Kernel Module

echo 'bcm2708_wdog' >> /etc/modules
sudo modprobe bcm2708_wdog

Install Watchdog Daemon

sudo apt-get install watchdog chkconfig
chkconfig watchdog on
sudo /etc/init.d/watchdog start

sudo vim /etc/watchdog.conf
# Uncomment the line watchdog-device = /dev/watchdog
# You might also want to uncomment max-load-1, or add something like "max-load-1 = 24" to reset your Pi if the load average exceeds 24 in any 1-minute span.

sudo /etc/init.d/watchdog restart

The watchdog daemon will send /dev/watchdog a heartbeat every 10 seconds. If /dev/watchdog does not receive this signal it will brute-force restart your Raspberry Pi.

If you are feeling adventurous you can test the setup by launching one of the fork-bombs you can find out there. Just make sure you don’t have anything of importance running.
: (){ :|:& };:

Thanks to gadgetoid for the original tip !

Dropping the wires on the Raspberry PI

Testing the RPi for some remote sensing application I needed to use a wireless connection as it would have been a pain to reach with an Ethernet cable.

Parts

  • Raspberry Pi Series B 512MB
  • Raspbian 3.6.11+ Kernel
  • Comfast 802.11n – Realtek RTL8188CUS WLAN Adapter

Install WPA Supplicant

sudo apt-get install wpasupplicant
See http://en.wikipedia.org/wiki/Wpa_supplicant

Check for the USB adapter

sudo lsusb
This should show output similar to this (depending on your USB adapter)
Bus 001 Device 004: ID 0bda:8176 Realtek SemicondRTL8188CUSuctor Corp. 802.11n WL:AN Adapter

Generate PSK Key

If you want to use the cleartext PSK you could probably skip this step.
wpa_passphrase YOUR_SSID YOURCLEARTEXTWPAKEY
This should show output similar to this:
network={
ssid="YOUR_SSID"
#psk="YOURCLEARTEXTWPAKEY"
psk=c885c4288a0c68b989289586cb075c0ccd1729d2c035820d02ed813fc729f317
}

Edit network configuration

sudo vim /etc/network/interfaces
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ssid "YOUR_SSID"
wpa-psk c885c4288a0c68b989289586cb075c0ccd1729d2c035820d02ed813fc729f317

Finish off

sudo shutdown -h now
Unplug ethernet cable
Power up the RPi and you should see another wireless DHCP assignment on the router

Webserver and database combination on Raspberry Pi

My normal combination on the big-server side would be Apache + MySQL (or PostgreSQL), but on the RPi this seems to be absolute overkill. For data-logging operations I would not use the local system anyway (looking at MQTT as well as Remote MongoDB datastore via REST Webservices).

After some poking around and reading up on the options I decided to go for the following combo: LightHTTPD + SQLite. Both are lightweight replacement of their fully-featured big-server counterparts (Apache HTTP & MySQL) and have very familiar configurations. There would be other options that have even less resource usage, but I really don’t have the time to start from scratch somewhere.

Another reason to go for this combination is that these are very well supported systems with regular security audits. Even though I am not planning to use my RPi’s for anything mission-critical this is always worth a consideration as you don’t need to unnecessarily introduce vulnerabilities to your network.

Install & configure LightHTTPD

sudo apt-get install lighttpd php5 php5-cgi php5-sqlite
sudo lighty-enable-mod fastcgi
sudo lighty-enable-mod fastcgi-php

Further config changes can be also made via the config file.
sudo vim /etc/lighttpd/lighttpd.conf
sudo service lighttpd force-reload

Install & configure SQLite

sudo apt-get install sqlite3
sqlite3 /home/username/database_name.db

All other commands are standard SQL from the ‘sqlite>’ command prompt or via SQL scripts like
sqlite3 /home/username/database_name.db < sql_script.sql

Access Databases from the webserver (using PHP)

< ?php $db = new SQLite3('mysqlitedb.db'); $results = $db->query('SELECT bar FROM foo');
while ($row = $results->fetchArray()) {
var_dump($row);
}
?>

See PHP: SQLite3::query – Manual for more details.

Raspberry Pi – Raspbian post install tasks

The Raspbian Install process is fairly well documented using the Raspbian Installer. This is just to document common tasks after the stock install.

Install base utils

apt-get install sudo vim ntpdate git-core binutils make gcc ca-certificates rpi-update

Allow non-root user account access to ‘sudo’

adduser USERNAME sudo
For those Ubuntu users there is no ‘admin’ group in Raspbian (Debian Wheezy).

NTP time update

sudo rm /etc/localtime
sudo ln -s /usr/share/zoneinfo/Australia/Adelaide /etc/localtime
sudo ntpdate -u au.pool.ntp.org

Probably best to choose an NTP Server closest to your location or provided by your ISP

Firmware upgrade

EDIT (2014-03-31): rpi-update is now part of the Raspbian repositories and can be installed via apt-get install rpi-update (I have added this to the above line).

Note: unless you want the latest firmware this is not a necessary step as apt-get will update the firmware to the latest stable release.

Using Hexxeh updater.

Install dependencies

wget http://goo.gl/1BOfJ -O /usr/bin/rpi-update && sudo chmod +x /usr/bin/rpi-update
sudo rpi-update

Install WiringPi

Thanks to the excellent work of Gordon Henderson (https://projects.drogon.net/raspberry-pi/wiringpi/) this is a C-based program to read/write to the Raspberry Pi GPIO pins.

cd /usr/share
git clone git://git.drogon.net/wiringPi
cd wiringPi
git pull origin
./build

Output:

wiringPi Build script
=====================

The wiringPi I2C helper libraries will not be built.

WiringPi library
[UnInstall]
[Compile] wiringPi.c
[Compile] wiringPiFace.c
[Compile] wiringSerial.c
[Compile] wiringShift.c
[Compile] gertboard.c
[Compile] piNes.c
[Compile] lcd.c
[Compile] piHiPri.c
[Compile] piThread.c
[Compile] wiringPiSPI.c
[Compile] softPwm.c
[Compile] softServo.c
[Compile] softTone.c
[Link (Dynamic)]
[Install]

GPIO Utility
[Compile] gpio.c
[Link]
[Install]

All Done.

Testing the install

gpio readall

Output:

+----------+------+--------+------+-------+
| wiringPi | GPIO | Name   | Mode | Value |
+----------+------+--------+------+-------+
|      0   |  17  | GPIO 0 | IN   | Low   |
|      1   |  18  | GPIO 1 | IN   | Low   |
|      2   |  21  | GPIO 2 | IN   | Low   |
|      3   |  22  | GPIO 3 | IN   | Low   |
|      4   |  23  | GPIO 4 | IN   | Low   |
|      5   |  24  | GPIO 5 | IN   | Low   |
|      6   |  25  | GPIO 6 | IN   | Low   |
|      7   |   4  | GPIO 7 | IN   | Low   |
|      8   |   0  | SDA    | ALT0 | High  |
|      9   |   1  | SCL    | ALT0 | High  |
|     10   |   8  | CE0    | ALT0 | High  |
|     11   |   7  | CE1    | ALT0 | High  |
|     12   |  10  | MOSI   | ALT0 | Low   |
|     13   |   9  | MISO   | ALT0 | Low   |
|     14   |  11  | SCLK   | ALT0 | Low   |
|     15   |  14  | TxD    | ALT0 | High  |
|     16   |  15  | RxD    | ALT0 | High  |
+----------+------+--------+------+-------+

Accessing 1-wire devices on Raspberry Pi using OWFS

To connect 1-wire serial devices to the RPi I am using a DS9490R USB 1-wire adapter (rather than wiring I2C 1-Wire master components to GPIO I2C – which I might look at sometime down the track)

Install packages

sudo apt-get install owfs ow-shell

Edit config file

vim /etc/owfs.conf

! server: server = localhost:4304
# USB device: DS9490
server: usb = all
######################### OWFS ##########################
mountpoint = /mnt/1wire
allow_other
####################### OWHTTPD #########################
http: port = 2121
####################### OWFTPD ##########################
ftp: port = 2120
####################### OWSERVER ########################
server: port = localhost:4304

Create Startup Script

I created a startup script for owfs modelled on the owserver script (not sure why this one is actually missing)

vim /etc/init.d/owfs

#!/bin/sh
### BEGIN INIT INFO
# Provides: owfs
# Required-Start: $remote_fs $syslog $network $named
# Required-Stop: $remote_fs $syslog $network $named
# Should-Start: owfs
# Should-Stop: owfs
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: 1-wire file system mount & update daemon
# Description: Start and stop 1-wire file system mount & update daemon.
### END INIT INFO
CONFFILE=/etc/owfs.conf
DESC="1-Wire file system mount"
NAME="owfs"
DAEMON=/usr/bin/$NAME
case "$1" in
start)
echo "Starting $NAME"
$DAEMON -c $CONFFILE
;;
stop)
echo "Stopping $NAME"
killall $NAME
;;
*)
echo "Usage: $N {start|stop}" >&2
exit 1
;;
esac
exit 0

Starting daemons

/etc/init.d/owserver start
/etc/init.d/owfs start

Checking output

#ls /mnt/1wire/

Should show output similar to:

10.575349000000 12.95DD17000000 alarm simultaneous uncached
10.575349000000 12.95DD17000000 bus.0 statistics
12.57DD16000000 81.B2EA2E000000 bus.1 structure
12.57DD16000000 81.B2EA2E000000 settings system

cat /mnt/1wire/10.575349000000/temperature

Will then show the temperature of the particular DS18S20 temperature sensor.

Installing OMXPlayer on Raspberry Pi

Since I didn’t have any luck playing videos on the RPi using mplayer I found omxplayer after some search. It has the ability to use the RPi’s GPU thus taking some load of the CPU.


UPDATE 2013-04-01: omxplayer is now included in the Raspbian (Debian Wheezy) repositories and can be simply installed by one line.

sudo apt-get install omxplayer

Check another article on how to install Raspbian.


OMXPlayer binary (.deb) downloads can be found here: http://omxplayer.sconde.net/

Install dependencies

apt-get install libpcre3 fonts-freefont-ttf fbset libpcre3-dev libpcrecpp0 libva-dev libva-x11-1 libva1

Install omxplayer

wget http://omxplayer.sconde.net/builds/omxplayer_0.2.4~git20121205~ec7ac68f_armhf.deb
dpkg -i omxplayer_0.2.4~git20121205~ec7ac68f_armhf.deb

Play video

omxplayer -o hdmi video.mp4

Note: If there is no sound when playing through the HDMI interface make sure your /boot/config.txt file has the following line (and it’s not commented out).

hdmi_drive = 2

OMXPlayer Key bindings

Key Action
1 Increase Speed
2 Decrease Speed
j Previous Audio stream
k Next Audio stream
i Previous Chapter
o Next Chapter
n Previous Subtitle stream
m Next Subtitle stream
s Toggle subtitles
q Exit OMXPlayer
Space or p Pause/Resume
Decrease Volume
+ Increase Volume
Left Seek -30
Right Seek +30
Down Seek -600
Up Seek +600

Raspberry Pi – Text to Speech

Just a quick note on Speech Synthesis a Raspberry Pi project. I had to research some of the options on the Raspberry Pi while looking into a project where I need some audio announcements.

Configuring Sound

echo 'snd-bcm2835' >> /etc/modules
sudo modprobe snd-bcm2835

sudo apt-get install mplayer alsa-base alsa-utils pulseaudio mpg123
# make mplayer use mpg123 codec instead of default ffmp3float
echo "afm=mp3lib" >> ~/.mplayer/config

Since I am using Raspbian which is a Debian based (Wheezy) Distribution I used some Ubuntu documentation (https://help.ubuntu.com/community/TextToSpeech) as the starting point.

Festival

sudo apt-get install festival festival-english
echo "Hello World - Testing" | festival --tts

Plus: Local install (no internet connection required)
Minus: Mechanical sounding voice

Espeak

sudo apt-get install espeak
espeak -v en "Hello World - Testing"

Plus: Local install (no internet connection required)
Minus: Mechanical sounding voice (slightly better than Festival)

Google Translate

Create a shell script tts.sh
#!/bin/bash
mplayer -ao alsa -noconsolecontrols "http://translate.google.com/translate_tts?tl=en&q=$*" > /dev/null 2>&1

chmot +x tts.sh
./tts.sh "Hello World - Testing"

Plus: needs live internet connection
Minus: excellent human sounding voice

Google Speech API

I will most likely look at this in the long run to get better control rather than calling the Google Translate url too much.