Raspberry Pi

Headless Installation

This is mostly taken from the article Setting up a Raspberry Pi headless

First, you'll need to format the SD card to install Rasbperry Pi OS.

Once you've done that, you'll need to mount the SD card to your computer once more. The volume should mount as boot.

We're going to create a file named wpa_supplicant.conf and add it to the root of the /boot Volume mounted on our computer.

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

If your WiFi doesn't have a password, you'll need to make some changes, as shown below.

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=COUNTRY
network={
    ssid="SSID"
    key_mgmt=NONE
}

You'll need to replace the following values:

SSID: the name of the WiFi network
PSK: the password of the WiFi network
COUNTRY: The 2-letter ISO 3166-1 country code

When the Raspberry Pi boots from this SD card, Raspberry Pi OS will move the contents of this file into /etc/wpa_supplicant/

Also, you'll probably want to enable SSH access, which is disabled by default. To do so, create an empty file ssh in the root folder of the /boot Volume mounted on our host machine.

touch /Volumes/boot/ssh

Now you can access the Raspberry Pi with the following credentials

Username: pi
Password: raspberry
Hostname: raspberrypi

Visit the official documentation to learn more about remote access to Raspberry Pi, or how to configure your Raspberry Pi

Customizing Video Resolution

Link to documentation

If you're using a 1920 x 1080 display for your raspberry pi, the text may appear too small. If you want to leverage pixel doubling to increase the UI scale (rendering each pixel as a 2x2 matrix), then add the following lines to your /boot/config.txt

hdmi_group=1
hdmi_mode=15

VNC

Documentation on Virtual Network Computing (VNC) implementation can be found here

SMB

Documentation on the Server Message Block (SMB) implementation can be found here

Useful Tricks

Measure temperature of Raspberry Pi
```
vcgencmd measure_temp
# temp=51.0'C
```

Print the MAC address of the ethernet and WiFi connections

cat /sys/class/net/eth0/address
cat /sys/class/net/wlan0/address

Alter the MAC address of a network device

# Bring the network interface "eth0" offline
ip link set dev eth0 down
# Alter the address of the network interface "eth0"
ip link set dev eth0 address a2:b4:c6:d8:e0:1d:2e
# Bring the network interface "eth0" online
ip link set dev eth0 up
# Check the address
ip link show eth0

Make the changed MAC address permanent

- to make it permanent, within /etc/network/interfaces, add the following stanza to the eth0 block: "pre-up ip link set dev eth0 address 02:03:04:05:06:07"

Write hello world to every terminal:
```
wall "hello world"
```
Enable receiving messages
```
mesg y
```
Send a message to the user tommy on tty1
```
ls | write tommy tty1
```

Change the current time on the computer

# Totally not when this was written...
sudo date -s '30 Nov 2019 04:38'

Enable booting to the command-line

sudo systemctl set-default multi-user.target

`cec-utils`

Consumer Electronics Control (CEC) is supported by most displays, including Samsung TVs. If your Raspberry Pi is connected to a Samsung TV via HDMI, you can use these commands.

Getting Started
```
sudo apt install cec-utils
```
Make the raspberry pi's console the active source for input
```
cec-client -s -d 1 <<< "as"
```
Turn the TV off (standby mode)
```
cec-client -s -d 1 <<< "standby 0"
```
Check the current TV status (on or off)
```
cec-client -s -d 1 <<< "pow 0"
```

Connecting to Airport Time Capsule

Create /etc/fstab

proc            /proc           proc    defaults          0       0
PARTUUID=c8e1868f-01  /boot           vfat    defaults          0       2
PARTUUID=c8e1868f-02  /               ext4    defaults,noatime  0       1
# a swapfile is not a swap partition, no line here
#   use  dphys-swapfile swap[on|off]  for that
//TMC_IP_ADDRESS/TMC_MOUNT_FOLDER /mnt/RPI_MOUNT_FOLDER cifs user=TMC_NAME,pass=TMC_PASSWORD,rw,uid=1000,iocharset=utf8,sec=ntlm,vers=1.0 0 0

Backups

mount -t cifs //chronos.local/Alexandria /mnt/delorean 
rsync -axHv --exclude-from exclude.txt --delete-during / /mnt/delorean/rpi/