Raspberry PI stuff

Various stuff about Raspberry Pi

I will try to put my experience in this post. I will start with the installation, and then go with other stuff. Here are shortcuts:
1. Installation
2. RPI3 with static IP Ethernet support
3. RPI Zero with static IP Wifi support,
4. Adding RPI Zero support for the Ethernet,
5. Static IP on both Ethernet and Wifi,
6. Installing Java,
7. Installing and configuring Samba,
8. Read-only file system,
9. Hardware watchdog for Raspberry Pi Zero.

Installation

You need to download the OS image from the official Raspberry PI site:

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

I prefer Raspbian with desktop.

Then you need to download the Etcher software for writing the OS image to the micro SD card:

https://etcher.io/

Put the micro SD card in your computer, start the Etcher, choose the image file and write.

When everything is done, remove the micro SD card safely from the PC, put it in the Raspberry PI, connect HDMI cable (in case of Zero, mini HDMI cable) from RPI to the monitor (or TV), and connect the keyboard to one of the USB ports (in case of RPI Zero, you need to connect your USB keyboard via adapter to the micro USB port). Connect the power cable. RPI will boot for the first time.

Default username/password is pi/raspberry.

Upon login, start the raspi-config by typing:

sudo raspi-config

This will start the configuration utility for the RPI. I use it to set up the new password, host name of the RPI and to turn on almost all interfacing options. When setting the interfacing options, I turn on the SSH, I2C, SPI and 1-wire. 

When exiting, the raspi-config will reboot the machine.

I prefer to set up the static IP to my RPIs, so here are some combinations:

1. Set up RPI 3 with the static IP on Ethernet,

2. Setup RPI Zero with the static IP on wireless,
3. Set up RPI Zero with the Ethernet support (needs additional ENC28J60 module to be connected to the RPI Zero).

Setting up RPI 3 with the static IP on Ethernet (and WiFi)

Before booting, connect the Ethernet cable from your router to the RPI 3, and connect the power. You can then log on. From that moment, you can set up the static IP address. Before that, you can check if the networking works. First of all, you can type:

ifconfig

This will write your IP address, which your RPI obtained from the router (via DHCP). If the IP address of the RPI begins, for example, with 192.168.1, then the static IP address will need to start the same way (remember first three numbers of the IP address). 

Here we have two branches:

1. from stretch, on with the buster builds of the Raspbian

2. before stretch build.

Stretch, buster, and newer builds

To set up the static IP address, you need to edit the /etc/network/interfaces file:

sudo nano /etc/network/interfaces

The nano editor will open the interfaces file. You can then put the following content:

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd

# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:

source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

auto eth0
allow-hotplug eth0
iface eth0 inet manual

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

Both eth0 and wlan0 (I have decided to assign my wlan0 static address, too) are set to manual. In case of wlan0, you need to edit the /etc/wpa_supplicant/wpa_supplicant.conf file to the basic content:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
   ssid="xxxx"
   psk="yyyy"
}

Then you need to add the following code to the end of the /etc/dhcpcd.conf file:

# Static eth0 IP configuration
interface eth0
static ip_address=192.168.1.207/24
static routers=192.168.1.1
static domain_name_servers=192.168.1.1 8.8.8.8
# Static wlan0 IP configuration
interface wlan0
static ip_address=192.168.1.217/24
static routers=192.168.1.1
static domain_name_servers=192.168.1.1 8.8.8.8

Before stretch (or buster) builds

To set up the static IP address, you need to edit the /etc/network/interfaces file:

sudo nano /etc/network/interfaces

The nano editor will open the interfaces file. You can then put the following content:

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd

# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:

source-directory /etc/network/interfaces.d

auto lo

iface lo inet loopback

allow-hotplug eth0

iface eth0 inet static

address 192.168.1.200

netmask 255.255.255.0

gateway 192.168.1.1

The address set in this example is 192.168.1.200. After that, you can restart the networking by typing:

sudo service networking restart

Or, you can reboot the RPI by typing:

sudo reboot

Setting up RPI Zero with the static IP on Wireless

RPI Zero W already has the wireless, while RPI Zero does not. In case of having the RPI Zero, you need to obtain WiFi dongle and some adapter to connect it to the micro USB port. After that, the procedure is the same for both RPI Zero W and RPI Zero.

Here too, we have two branches:
1. stretch/buster builds.
2. pre-stretch(or buster) builds

Stretch, buster, and newer builds

Just look above at the same title.

Before stretch (or buster) builds

You need to edit the /etc/network/interfaces by typing:

sudo nano /etc/network/interfaces

In the nano editor, change the interfaces file to:

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd

# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:

source-directory /etc/network/interfaces.d

auto lo

iface lo inet loopback

allow-hotplug wlan0

iface wlan0 inet static

#    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

        wpa-ssid "MySSID"

        wpa-psk "xxxxxx"

address 192.168.1.201

netmask 255.255.255.0

gateway 192.168.1.1

The address set in this example is 192.168.1.201. The MySSID is the SSID of your WiFi network. You must enter the SSID and the password with the quotes (").

Setting up RPI Zero for the Ethernet support

RPI Zero supports the ENC28J60 Ethernet module out of box.

ENC28J60 Ethernet module

This module needs to be connected to the RPI Zero via SPI interface. Don't forget to enable the SPI from the raspi-config tool (look above). After that, you need to do the following:

1. Connect the ENC28J60 module to the RPI using the following pin scheme:

Pi            PinNo ENC28J60     

---------------------------------

+3V3          17 VCC          

GPIO10/MOSI    19 SI           

GPIO9/MISO    21 SO           

GPIO11/SCLK    23 SCK          

GND            20 GND          

GPIO25        22 INT          

CE0#/GPIO8    24 CS           

2. Enable the ENC28j60 module at the end of your /boot/config.txt file by typing:

sudo nano /boot/config.txt

This will open the nano editor. Go to the end of the file and enter the following text:

dtoverlay=enc28j60

3. Reboot (sudo reboot)

From this moment on, you can work with the Ethernet as eth0 device.

Having static IP on both Ethernet and WiFi

The text below is for the pre-stretch/buster builds. For having both ethernet and WiFi static, look above, at the "Setting up RPI 3 with the static IP on Ethernet (and WiFi)" title.

If you want to have the static IP on both Ethernet port and WiFi, you need to edit the /etc/network/interfaces file and put the following text:

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd

# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:

source-directory /etc/network/interfaces.d

auto lo

iface lo inet loopback

#allow-hotplug eth0

iface eth0 inet static

address 192.168.1.202

netmask 255.255.255.0

gateway 192.168.1.1

auto wlan0

#allow-hotplug wlan0

iface wlan0 inet static

#    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

        wpa-ssid "MySSID"

        wpa-psk "xxxxxxx"

address 192.168.1.212

netmask 255.255.255.0

gateway 192.168.1.1

The address set in this example for the Ethernet is 192.168.1.202 and for the WiFi is 192.168.1.212. 

Installing Java8 on your RPI

Type the following in your console:

sudo aptitude install oracle-java8-jdk

This will install the Java8 installer and would run it. 

Samba support

Samba allows you to share a part of your RPI disk to the network, for other machines and users. It also allows you to access other samba shares on the network. We will focus on the sharing of our disk on the network.

Install Samba via apt-get:

sudo apt-get install samba samba-common-bin

Edit the smb.conf file using nano:

sudo nano /etc/samba/smb.conf

Find the entries for workgroup and wins support, and set them up as follows:

workgroup = your_workgroup_name

wins support = yes

You also need to add the following section to end of the smb.conf to add share:

[pihome]

   comment= Pi Home

   path=/home/pi

   browseable=Yes

   writeable=Yes

   only guest=no

   create mask=0777

   directory mask=0777

   public=no

This will add the Samba share named "pihome" on your RPI, so it will be accessible from other machines.

At the end, we need to add the current user to the Samba:

sudo smbpasswd -a pi

After that, just restart the smbd daemon:

sudo systemctl restart smbd