Preparing a Raspberry Pi Zero with WiFi and SSH

When working with a Raspberry Pi Zero W, as there is no network port, you will need to enable WiFi and SSH as well so that you can connect to it when it first boots.

This is far simpler than the alternative, which is to connect a keyboard and monitor to the Raspberry Pi Zero W to then set up WiFi and SSH. You can simply use your existing setup.

Prepare the SD Card

You will need a microSD card and a USB adapter. These are all cheap and plentiful, some examples of adapters are here and here. Plug your microSD card into a USB adapter, then plug it into your computer.

USB SD Adapter

Download OS image

The official image for Raspberry Pi in general is Raspbian, which can be downloaded here. If you don’t need a desktop environment, download the Lite version. Not having a desktop environment frees up valuable memory and CPU.

raspbian images

Optionally, if you have WSL you can download and also verify the checksum.

/c/Users/mendhak/Downloads$ wget -O raspbian.zip https://downloads.raspberrypi.org/raspbian_lite_latest 
/c/Users/mendhak/Downloads$ sha256sum raspbian.zip
12ae6e17bf95b6ba83beca61e7394e7411b45eba7e6a520f434b0748ea7370e8  raspbian.zip

Flash the SD Card

Download Balena Etcher, choose the portable version from the dropdown.

etcher

Launch Etcher, then select the zip file that you just downloaded, and choose the USB device carefully.

etcher

Click Flash and the image should get written to the SD card shortly.

etcher

Configure the OS

Once flashing is complete, unplug and replug the USB adapter. The drive should now appear in Windows (it appeared as D:\ for me) filled with OS files for the Raspberry Pi.

boot drive

You now need to allow the Raspberry Pi Zero W to connect to your network and allow yourself to connect to it.

Enable SSH

Raspbian disables SSH by default. To enable it, create an empty file in this drive, called ssh.

enable ssh

Just the presence of this empty file on disk is enough for Raspbian to enable SSH when you power up the Raspberry Pi later.

Enable WiFi

You will need to tell Raspbian how to connect to your WiFi.

Create a file called wpa_supplicant.conf in the same boot drive. Paste these contents in there, and replace the country, SSID and PSK values.

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

network={
     ssid="your_network_name"
     psk="your_wifi_password"
     key_mgmt=WPA-PSK
}

Raspberry Pi Zero W does not support 5 GHz, make sure you have 2.4 GHz enabled on the SSID that you are connecting to.

The country code is not always necessary, but helps the WiFi radio figure out which channels it can operate on as different nations may ban the use of certain frequencies based on military, security, industrial/scientific requirements. Without the country code in place, the WiFi may simply refuse to connect.

Run the Raspberry Pi Zero W

Plug the SD Card into the Raspberry Pi Zero W. Connect a micro-USB cable and power up the Pi. You can use the official Raspberry Pi power supply (~2.5A) or a USB port that supplies adequate power (~1.2A).

raspberry pi zero wh

Wait a few minutes, then have a look at the list of connected devices on your router’s admin pages and find its IP address. If you’re having trouble figuring it out, pick one, start pinging it, and disconnect your most recent Pi to see if that’s the right IP.

pihole devices

Once you have the right IP, ssh to it with the default password of raspberry

You’re now connected to the Raspberry Pi.

Change password

As a best practice, run sudo raspi-config and follow the prompts to change your password.

pihole devices

Change hostname

Under sudo raspi-config, choose Network Options, then Hostname. Set the name to something distinctive from other Raspberry Pis.
After renaming you will be prompted to reboot.

Increase swap space

Open up the swap configuration file

sudo nano /etc/dphys-swapfile

Change the CONF_SWAPSIZE value from 100 to something larger, like 2048, then save and exit. Restart the swap service.

sudo /etc/init.d/dphys-swapfile stop
sudo /etc/init.d/dphys-swapfile start

Verify the new swap space using free -m

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