Raspberry Pi

樹莓派是基於Linux的單晶片電腦，由英國樹莓派基金會開發，目的是以低價硬體及自由軟體促進學校的基本電腦科學教育。

Learning

Tutorials
Pi Kiosk
Hardware

Picroft

Introduction

Picroft is a ready-made way to run Mycroft on a Raspberry Pi 3, 3B+ or 4 and is provided as a disk image that you can burn to a Micro SD card.

 

 

Raspberry Pi OS

Installation

Ubuntu 22.04

sudo apt install rpi-imager

Create User

NOTE: 新版 Raspberry Pi OS 已經移除內建帳號 pi。使用前需要手動先建立帳號。

Headless Setup

SD Card > Boot partition > File: userconf

userconf:

alang:<encrypted-password>

Generate encrypted password

echo 'mypassword' | openssl passwd -6 -stdin
CLI
# Add user
sudo adduser <username>
sudo usermod -a -G adm,dialout,cdrom,sudo,audio,video,plugdev,games,users,input,netdev,gpio,i2c,spi <username>

# Delete user
sudo deluser -remove-home <username>

Enable SSH

Default credential is pi / raspberry
Headless setup

SD Card > Boot partition > File: ssh (an empty file)

SSH can be enabled by placing a file named ssh, without any extension, onto the boot partition of the SD Card.

Desktop
  1. Launch Raspberry Pi Configuration from the Preferences menu
  2. Navigate to the Interfaces tab
  3. Select Enabled next to SSH
  4. Click OK

Option #3: Using the raspi-config

  1. Enter sudo raspi-config in a terminal window
  2. Select Interfacing Options
  3. Navigate to and select SSH
  4. Choose Yes
  5. Select Ok
  6. Choose Finish

Wireless LAN

Headless setup

SD Card > Boot partition > File: wpa_supplicant.conf

wpa_supplicant.conf :

country=TW # Your 2-digit country code
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
network={
    ssid="YOUR_NETWORK_NAME"
    psk="YOUR_PASSWORD"
    key_mgmt=WPA-PSK
}
CLI

rasp-config CLI

# Usage: sudo raspi-config nonint do_wifi_ssid_passphrase <ssid> <passphrase> [hidden] [plain]
sudo raspi-config nonint do_wifi_ssid_passphrase myssid 'mypassphrase' 0 0 # Visible SSID, passphrase quoted

nmcli

nmcli dev wifi list
sudo nmcli dev wifi connect <example_ssid>
sudo nmcli --ask dev wifi connect <example_ssid> hidden yes

 

Python

Install pip

sudo apt install python3-pip
pip --version
sudo pip install --upgrade pip

雖然 pip 可以成功安裝，不過要繼續安裝 3rd-party 套件時，會遇到以下錯誤。

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
    python3-xyz, where xyz is the package you are trying to
    install.
    
    If you wish to install a non-Debian-packaged Python package,
    create a virtual environment using python3 -m venv path/to/venv.
    Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
    sure you have python3-full installed.
    
    For more information visit http://rptl.io/venv

新版 Raspberry Pi OS 已經不允許直接安裝 3rd-party 套件；而是必須在 python 虛擬環境才能安裝套件。

建立 python 虛擬環境

# 以下指令在 user 帳號下執行，例如 pi
mkdir myproject
cd myproject
python -m venv env
source env/bin/activate
which python
# 記得先升級 pip 至最新版
pip install --upgrade pip
# 開始安裝套件
pip install paho-mqtt
# 檢視已安裝套件
pip list

要執行 python 程式時，開頭宣告指向虛擬環境的 python，可以避免需要手動進入 python venv。

#!<path-to-venv>/bin/python

PiShrink

Dumping existing image

Install cockit on Raspberry Pi

sudo apt install cockpit

Shutdown Raspberry PI, take out the SD card, and connect it to your PC.

The boot- and rootfs-partitions were automatically mounted at the mentioned mount points. Before you proceed, unmount them with :

umount /dev/mmcblk0p1
umount /dev/mmcblk0p2

Now we copy the contents of the SD card to our file system.

sudo dd if=/dev/mmcblk0 of=/home/alang/worktmp/PiShrink/my_rasp.v2.img bs=32M

Download the PiShrink

https://github.com/Drewsif/PiShrink 

Now invoke the script by typing:

sudo ./pishrink.sh my_rasp.v2.img
Flash the image to the SD card

 

 

 

 

Xiaomi Mijia Temperature and Humidity Sensor

硬體規格

Raspberry Pi OS

藍芽
不需要與溫濕度計做配對，就可以直接讀資料。
bluetoothctl
> scan on
> devices
> scan off
> exit
安裝 Python module
NOTE: 新版 Pi OS 只允許在 Python venv 環境下用 pip 安裝第三方套件。
# 以下指令必須用 user 帳號下執行 (non-root)
mkdir mitemp
cd mitemp
python -m venv env
source env/bin/activate
which python
# 記得先升級 pip 至最新版
pip install --upgrade pip
# 開始安裝套件
sudo apt install libglib2.0-dev
pip install bluepy
pip install lywsd03mmc
pip install paho-mqtt
錯誤：ERROR: Could not build wheels for bluepy, which is required to install pyproject.toml-based projects

解決：

sudo apt install libglib2.0-dev

Telegraf

Option 1: Python script

建立設定檔

mv /etc/telegraf/telegraf.conf /etc/telegraf/telegraf.conf.orig
telegraf --input-filter exec --output-filter influxdb_v2 config > /etc/telegraf/telegraf.conf

telegraf.conf

[[outputs.influxdb_v2]]
  urls = ["http://127.0.0.1:8086"]

  ## Token for authentication.
  token = "YOUR-TOKEN"
  ## Organization is the name of the organization you wish to write to.
  organization = "YOUR-ORAG"
  ## Destination bucket to write into.
  bucket = "YOUR-BUCKET"

  ## Timeout for HTTP messages.
  timeout = "5s"


[[inputs.exec]]
    interval = "180s"
    commands = ["sudo -u pi /home/pi/mitemp/env/bin/python /home/pi/mitemp/go-mitemp.py"]

    ## Timeout for each command to complete.
    timeout = "30s"

    ## Data format to consume.
    ## Each data format has its own unique set of configuration options, read
    ## more about them here:
    ## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
    data_format = "influx"

Test the configuration

telegraf -config /etc/telegraf/telegraf -test

Set the sudo for telegraf

NOTE: Pi OS 的 telegraf 服務是用 non-root 帳號啟動，如果要執行另一個帳號的 script，必須使用 sudo。

Edit: /etc/sudoers.d/011_telegraf-nopasswd

telegraf ALL=(ALL) NOPASSWD: /home/pi/mitemp/env/bin/python /home/pi/mitemp/go-mitemp.py

Option 2: MQTT Consumer

Tutorials

Monitoring

Tutorials 

Telegraf + InfluxDB + Grafana

Telegraf + InfluxDB

Dashboard ID 17191

telegraf.conf:

[[outputs.influxdb_v2]]
  ## The URLs of the InfluxDB cluster nodes.
  ##
  ## Multiple URLs can be specified for a single cluster, only ONE of the
  ## urls will be written to each interval.
  ##   ex: urls = ["https://us-west-2-1.aws.cloud2.influxdata.com"]
  urls = ["http://your.influxdb.server:8086"]

  ## Token for authentication.
  token = "THIS-IS-TOKEN"

  ## Organization is the name of the organization you wish to write to.
  organization = "YOUR-ORG"

  ## Destination bucket to write into.
  bucket = "YOUR-BUCKET"
[[inputs.net]]
[[inputs.netstat]]
[[inputs.file]]
  files = ["/sys/class/thermal/thermal_zone0/temp"]
  name_override = "cpu_temperature"
  data_format = "value"
  data_type = "integer"
[[inputs.exec]]
#Für ein 32bit System (welches überwacht werden soll)
  commands = ["/usr/bin/vcgencmd measure_temp"] 
#oder für ein 64bit System (welches überwacht werden soll), dann die Raute(#) entfernen und bei 32bit die Raute hinzufügen
# commands = ["/usr/bin/vcgencmd measure_temp"]
  name_override = "gpu_temperature"
  data_format = "grok"
  grok_patterns = ["%{NUMBER:value:float}"]
# Read metrics about cpu usage
[[inputs.cpu]]
  ## Whether to report per-cpu stats or not
  percpu = true
  ## Whether to report total system cpu stats or not
  totalcpu = true
  ## If true, collect raw CPU time metrics
  collect_cpu_time = false
  ## If true, compute and report the sum of all non-idle CPU states
  report_active = false
  ## If true and the info is available then add core_id and physical_id tags
  core_tags = false
# Read metrics about disk usage by mount point
[[inputs.disk]]
  ## By default stats will be gathered for all mount points.
  ## Set mount_points will restrict the stats to only the specified mount points.
  # mount_points = ["/"]
  ## Ignore mount points by filesystem type.
  ignore_fs = ["tmpfs", "devtmpfs", "devfs", "iso9660", "overlay", "aufs", "squashfs"]
  ## Ignore mount points by mount options.
  ## The 'mount' command reports options of all mounts in parathesis.
  ## Bind mounts can be ignored with the special 'bind' option.
  # ignore_mount_opts = []
# Read metrics about disk IO by device
[[inputs.diskio]]
  ## By default, telegraf will gather stats for all devices including
  ## disk partitions.
  ## Setting devices will restrict the stats to the specified devices.
  # devices = ["sda", "sdb", "vd*"]
  ## Uncomment the following line if you need disk serial numbers.
  # skip_serial_number = false
  #
  ## On systems which support it, device metadata can be added in the form of
  ## tags.
  ## Currently only Linux is supported via udev properties. You can view
  ## available properties for a device by running:
  ## 'udevadm info -q property -n /dev/sda'
  ## Note: Most, but not all, udev properties can be accessed this way. Properties
  ## that are currently inaccessible include DEVTYPE, DEVNAME, and DEVPATH.
  # device_tags = ["ID_FS_TYPE", "ID_FS_USAGE"]
  #
  ## Using the same metadata source as device_tags, you can also customize the
  ## name of the device via templates.
  ## The 'name_templates' parameter is a list of templates to try and apply to
  ## the device. The template may contain variables in the form of '$PROPERTY' or
  ## '${PROPERTY}'. The first template which does not contain any variables not
  ## present for the device is used as the device name tag.
  ## The typical use case is for LVM volumes, to get the VG/LV name instead of
  ## the near-meaningless DM-0 name.
  # name_templates = ["$ID_FS_LABEL","$DM_VG_NAME/$DM_LV_NAME"]
# Get kernel statistics from /proc/stat
[[inputs.kernel]]
  # no configuration
# Read metrics about memory usage
[[inputs.mem]]
  # no configuration
# Get the number of processes and group them by status
[[inputs.processes]]
  # no configuration
# Read metrics about swap memory usage
[[inputs.swap]]
# Read metrics about system load & uptime
[[inputs.system]]

Set the sudo

sudo usermod -aG video telegraf

Optimization

Disable Desktop Booting

raspi-config > 1 System Options > S5 Boot / Auto Login

Limit GPU Memeory to 16B

 raspi-config > 4 Performance Options >  P2 GPU Memory

Disable HDMI

Edit /etc/rc.local

/usr/bin/tvservice -o
exit 0
Disable Bluetooth
sudo systemctl disable hciuart
systemctl disable bluetooth.service

Edit /boot/config.txt

dtoverlay=disable-bt
Disable Onboard LED

Edit /boot/config.txt

dtparam=pwr_led_trigger=none
dtparam=pwr_led_activelow=off

dtparam=act_led_trigger=none
dtparam=act_led_activelow=off

 

 

USB to TTL

Tutorials
Hardware

DietPi

DietPi is a highly optimised & minimal Debian-based Linux distribution. DietPi is extremely lightweight at its core, and also extremely easy to install and use.

Setting up a single board computer (SBC) or even a computer, for both regular or server use, takes time and skill. DietPi provides an easy way to install and run favourite software you choose.