1. Raspberry Pi initial setup¶

Unless purchased as part of a “product bundle” each raspberry-pi arrives as a single-board-computer. Nothing else. Each board requires:

Micro SD card (class 10, UHS-1 for faster speed. 16gb or 32gb)
Power supply (see here )
Optional: keyboard, mouse, monitor.

1.1. Flash Operating System to the SD-card¶

The “Rasbian” operating system which is based on the debian linux distribution and provided by the Raspberry Pi Foundation works fine for most purposes.

The Raspberry Pi Foundation now provides a utility for choosing the OS and then imaging directly to the SD-Card. Alternatively for a little more control:

Download and save in a folder the latest Rasbian images from here. The full version includes a GUI for the OS and other software. The lite version which does not come with a GUI nor other software will suffice when accessing the pi from the command line over ssh.
Flash the image onto an SD Card using etcher for Mac OS.

In the boot partition create an empty file to enable ssh

sudo diskutil mount /dev/disk2s1  #or whatever the boot partition is

cd /volumes/boot

touch ssh

Enable connection to wifi by creating a wpa_supplicant.conf file in the same boot partition:
```
nano wpa_supplicant.conf
```

and enter the following information:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid="NETWORK-NAME"
    psk="NETWORK-PASSWORD"
    key_mgmt=WPA-PSK
}

Save the file and exit. Unmount and eject the SD card and insert into the Raspberry Pi and power on.

1.2. Additional OS configurations¶

Access and login to the raspi over wifi:
- Login into the router portal (eg) http://192.168.1.1 in order to determine which IP address the router has assigned to the new device that is now connected to the network. This can also be done using a network scanner. Then ssh into the pi:
ssh pi@192.168.1.186
- Alternatively, if the raspberry pi is the only one on the network (or at least the only one that is still has the default hostname raspberrypi then you can access more generically with:
```
ssh pi@raspberrypi.local
```

Update the OS and other programs

Likely not needed any more but to be on the safe side expand the file-system to take advantage of the SD-card capacity:
```
sudo raspi-config --expand-rootfs
```
Update various configurations via command line via sudo raspi-config:
- password
- set the locale
- update timezone
- set a hostname (eg rasp-4a)
- enable vnc

If the light version of the OS is installed or the raspi is only ever going to be used via the command-line as a headless device then the gpu memory allocation can be reduced to the 16mb minimum. Set via advanced options in raspi-config, or directly in the boot config file:

sudo nano /boot/config.txt

and add the following line at the bottom: gpu_mem=16

Install any linux command-line utilities and programs as needed. eg to install screen, basic calculator bc etc.
```
sudo apt-get install screen
sudo apt-get install bc
```

1.3. Enable VNC access¶

In the same way that SSH (Secure Shell) allows access to the command line of the raspberry pi, VNC (Virtual Networking Computing) allows access to the GUI of the raspberry pi if/when needed.

Enable VNC via `sudo raspi-config` if not already done.

Set a password via:

sudo vncpasswd -service

#should return "Successfully set password VNC parameter in /root/.vnc/config.d/vncserver-x11"

Create the following file containing a single line:

sudo nano /etc/vnc/config.d/common.custom

Authentication=VncAuth

Then restart the vnc service:

sudo systemctl restart vncserver-x11-serviced

You may need to re-enable vnc via raspi-config and you may also need to install and run tightvncserver.

When accessing the desktop UI remotely we first need to sudo raspi-config and set resolution to something that makes sense depending on the client (usually the highest resolution for a mac) and also set boot to desktop.

From a safari browser the navigate to vnc://192.168.1.184 and enter password when prompted.

1.4. SSH key and public key¶

Access to the raspberry pi via SSH from within your network is usually safe, but if access is desired from outside the local network (ie internet) then a mere username + password combination may be vulnerable.

Security can be enhanced with the use of SSH key and public key for authentication. More information on the SSH protocal, keys etc can be found here.

In the home ``~``directory of the mac client machine generate the key, set a passphrase for the private key, and copy the public key to the pi
```
ssh-keygen

ssh-copy-id pi@192.168.1.184
```

If the private key is likly to be one of many then rename it. Delete the public key or achive it somewhere.

mv id_rsa raspi4a

rm id_rsa.pub

You may need to chmod 600 raspi4a for correct permissioning.

On the raspberry-pi server update various configuration by opening:
```
sudo nano /etc/ssh/sshd_config
```

Uncomment/enable PubkeyAuthentication yes. Set the Port number to match port-forwarding on the router, and make sure enable PasswordAuthentication no.

Log-in to the network router/switch and enable port-fowarding with the port number (avoid the common Port 22…) mapped to the raspberry pi.
Restart the service with sudo service ssh restart
Confirm that the selected port is listerning: netstat -tnl