Raspberry Pi Zero W

Buy

• https://www.raspberrypi.org/products/raspberry-pi-zero-w/ (~15$)

Setup

Create a bootable SD card

Download Raspberry Pi Imager

• Download the Raspberry Pi Imager tool and install it

Download and Flash IMG

Use the Raspberry Pi Imager to download and create a bootable SD card

• Insert an SD card to your computer
• Launch the Raspberry Pi Imager tool
• Choose OS Raspberry Pi OS (other) > Raspberry Pi OS Lite
• Choose SD Card
• Flash the (zipped) Raspbian Lite IMG to the SD card
• Remove and re-insert the SD card to your computer
• There should now be a disk drive named boot

Enable SSH

Create an ssh marker file on the SD card

• The following file will enable sshd, the SSH daemon, on the Raspberry Pi
• Navigate to the disk drive named boot and create an empty file named ssh with

  $ cd /Volumes/boot
  $ touch ssh

  or on Windows, assuming the boot drive is E:

  C:> E:
  E:> type nul > ssh

• Note: once sshd is enabled, the Raspberry Pi will remove the ssh file

Enable RNDIS

Edit configuration files on the SD card

• The following edits convert the Raspberry into a RNDIS USB device
• Open config.txt and append dtoverlay=dwc2

  $ cd /Volumes/boot
  $ open config.txt
  $ cat config.txt
  …
  dtoverlay=dwc2

• Open cmdline.txt and add modules-load=dwc2,g_ether after rootwait

  $ cd /Volumes/boot
  $ open cmdline.txt
  $ cat cmdline.txt
  … rootwait modules-load=dwc2,g_ether …

Configure Wi-Fi

• Create wpa_supplicant.conf

• On the disk drive named boot, create an empty file named wpa_supplicant.conf

  $ cd /Volumes/boot
  $ touch wpa_supplicant.conf
  $ open wpa_supplicant.conf

• For content and options, see Configure Wi-Fi

Connect the USB

• Insert the SD card into the Raspberry Pi (it is the Pi's "hard disk")
• Connect the USB cable, use the left USB connector on the Raspberry Pi

Get USB access from Windows

Install RNDIS driver on Windows

• Download http://web1.moddevices.com/shared/mod-duo-rndis.zip
  (see https://forum.moddevices.com/t/rndis-driver-for-windows-10/299)
• Open device management (WINDOWS-R, type cmd, RETURN, type devmgmt.msc, RETURN)
• Find the new USB device in the device tree (e.g. COM3, usually showing a warning)
• Right click the USB device, click Update driver software...
• Choose Install from disk, select the mod-duo-rndis.zip downloaded above
• The USB device should now show up as an RNDIS device

Install Bonjour 3.x on Windows

• Download iTunes installer https://www.apple.com/itunes/download/win64
• Unpack the installer EXE/ZIP, find the Bonjour64.msi installer inside
• Run Bonjour64.msi, select Bonjour uninstall old version
• Run Bonjour64.msi, select Bonjour install 3.0

Share Internet to RNDIS

• Wi-Fi > Properties > Sharing > [✓] Allow

Get USB access from Mac

Share Internet to RNDIS

• System Preferences > Sharing > [✓] Internet
• Sharing > Share your connection from: Wi-Fi to computers using RNDIS Ethernet Gadget

Get USB access from Linux

Share Internet to RNDIS

• https://superuser.com/questions/1150562/how-to-connect-to-a-raspberry-pi-zero-to-an-ubuntu-laptop-by-usb/1219319#1219319

Find your Pi

To find your Pi Zero via USB (if Internet Sharing is enabled), type

$ dns-sd -G v4 raspberrypi.local

Or, use ifconfig (or ipconfig on Windows) you find the local IP prefix, e.g. 192.168.0.

$ ifconfig
en0: flags…
    ether…
    inet6…
    inet 192.168.0.23
    …

Then use nmap to scan the subnet, e.g.

Note: make sure port scanning is fine with the local network admin, e.g. at FHNW it's not allowed.

$ % sudo nmap -sS -p22 192.168.2.0-255
Nmap scan report for 192.168.0.42
…
22/tcp open  ssh

Access your Pi

With ssh (or PuTTY on Windows), default password raspberry

$ ssh [email protected]

Or, via USB, if there's only one Pi

$ ssh [email protected]

Or via FTDI Serial (up to Pi 2, or with this fix for Pi 3).

3V3 (!), Pin 6 = GND, 8 = TX, 10 = RX

Remotely access your Pi

Use a relay service like Ngrok, Pagekite or Yaler.net.

Configure Wi-Fi

https://www.raspberrypi.org/documentation/configuration/wireless/wireless-cli.md

Open the Wi-Fi config

$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

Then set the Wi-Fi credentials

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

network={
    ssid="MY_SSID"
    psk="MY_PASSWORD"
    key_mgmt=WPA-PSK
}

Consider using the hashed version of psk, see output of

$ sudo wpa_passphrase 'MY_SSID' 'MY_PASSWORD'

To activate the new config, type

$ sudo ifconfig wlan0 up

For setup, create the same file on the boot partition of the SD card (on Stretch)

wpa_supplicant.conf

Configure interface priorities

To display the priority metric, use

$ route -n

To change the priority metric (here wlan0 before usb0), type

$ sudo nano /etc/dhcpcd.conf

interface wlan0
    metric 200

interface usb0
    metric 300

Get the MAC Address

$ cat /sys/class/net/wlan0/address

Install git

Install the git client

$ sudo apt-get update
$ sudo apt-get install git
$ git

Configure git user

$ git config --global user.email "USER_EMAIL"
$ git config --global user.name "USER_NAME"

Create an SSH key

$ ssh-keygen -t rsa -b 4096 -C "USER_EMAIL"
$ eval "$(ssh-agent -s)"
$ cat ~/.ssh/id_rsa.pub

Register the key

• Go to https://github.com/settings/keys

  User Icon > Settings > SSH and GPG keys > New SSH key > {Paste SSH key}

Store the key

$ sudo apt-get install keychain
$ keychain ~/.ssh/id_rsa
$ . ~/.keychain/$HOSTNAME-sh

(Until next reboot)

Code

Java

Install

• https://www.raspberrypi.org/blog/oracle-java-on-raspberry-pi/

  $ sudo apt-get update && sudo apt-get install oracle-java7-jdk

• Optional:

  $ sudo apt-get install maven

Libraries & Examples

• http://pi4j.com/ (wiringPi wrapper in Java)

  $ curl -s get.pi4j.com | sudo bash

• http://pi4j.com/example/serial.html
• http://pi4j.com/example/control.html

Javascript with Node.js

• https://nodejs.org/

Install Node.js

• Get the latest LTS (long term support) version from https://nodejs.org/en/download/ e.g. v10.15.3
• Or use a previous version from https://nodejs.org/en/download/releases/ (for compatibility)
• Use the following commands with the selected version, e.g. for v10.15.3

  $ wget https://nodejs.org/dist/v10.15.3/node-v10.15.3-linux-armv6l.tar.gz
  $ tar -xzf node-v10.15.3-linux-armv6l.tar.gz
  $ cd node-v10.15.3-linux-armv6l/
  $ sudo cp -R * /usr/local/
  $ node -v
  v10.15.3

Install Noble (BLE Central)

• Update apt-get with

  $ sudo apt-get update

• Install prerequisites with

  $ sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev

• Install the abandonware fork of noble with

  $ npm install @abandonware/noble

Libraries & Examples

• https://www.npmjs.com/package/rpi-gpio
• https://nodejs.org/api/stream.html
• https://github.com/abandonware/noble (BLE Central)
• https://github.com/abandonware/bleno (BLE Peripheral)

Python

• https://www.raspberrypi.org/documentation/linux/software/python.md (Installing Python packages)
• https://github.com/RPi-Distro/python-gpiozero
• https://github.com/Seeed-Studio/grove.py
• http://www.bluez.org/ (BLE)

C

• http://wiringpi.com/
• https://github.com/tamberg/fhnw-syspr

Pinout

• https://pinout.xyz/
• https://pinout.xyz/pinout/uart
• https://pinout.xyz/pinout/wiringpi

Resources

• https://www.raspberrypi.org/products/raspberry-pi-zero-w/
• https://learn.adafruit.com/series/learn-raspberry-pi
• http://www.tamberg.org/fhnw/2019/Syspr00Einfuehrung.pdf (p.21 ff.)