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OPi-one Setup Guide

Follow these steps to install OPi-one on your Raspberry Pi 4 and start blocking ads and trackers across your whole home network.

⏱ About 15 minutes to complete

What You Need

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Raspberry Pi 4

2GB, 4GB, or 8GB RAM

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MicroSD Card

16GB or larger (Class 10 or faster)

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Ethernet Cable

To connect the Pi to your router

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Power Supply

USB-C, 5V / 3A (official Pi power supply recommended)

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A Computer

To write the software to the memory card

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Your Home Router

You'll need access to its settings page

1

Download the OPi-one Image

Download the OPi-one software image (100MB). This file contains everything pre-configured — you don't need to install or set anything up manually.

⬇️ Download OPi-one Image (100MB)

Once downloaded, unzip the file to get the .img file inside.

2

Write the Image to Your Memory Card

You need to copy the OPi-one software onto your microSD card. Use one of these free tools to do it — they handle everything for you:

Raspberry Pi Imager (Recommended)

Official tool from the Raspberry Pi Foundation. Simple and reliable.

Available for Windows, Mac, and Linux at raspberrypi.com/software

Balena Etcher

Another popular option. Drag, drop, and flash.

Available at etcher.balena.io

  1. a. Insert your microSD card into your computer (use an adapter if needed)
  2. b. Open Raspberry Pi Imager or Balena Etcher
  3. c. Select "Use custom image" and choose the .img file you downloaded
  4. d. Select your microSD card as the target
  5. e. Click "Write" or "Flash" and wait for it to finish (takes a few minutes)
3

Boot Your Raspberry Pi

  1. a. Insert the microSD card into your Raspberry Pi 4 (the slot is on the underside)
  2. b. Connect an ethernet cable between the Pi and your router
  3. c. Plug in the power supply — the Pi will start automatically
  4. d. Wait about 60–90 seconds for it to fully start up
Tip: A solid red light means the Pi has power. A flashing green light means it is reading from the SD card and booting up.
4

Find Your Pi's IP Address

To use OPi-one, you need to know the IP address your router has assigned to your Raspberry Pi. An IP address looks like 192.168.1.X. Here are three ways to find it:

Option A — Check Your Router's Admin Page Easiest

  1. 1. Open a browser and go to your router's settings page. Common addresses are 192.168.1.1 or 192.168.0.1. Check the label on your router if unsure.
  2. 2. Log in (credentials are usually on a sticker on your router)
  3. 3. Look for a section called "Connected Devices", "DHCP Clients", or "LAN Clients"
  4. 4. Find the device named guardhero or raspberrypi — note its IP address

Option B — Try the Default Hostname

From any device on the same network, open a browser and try: http://guardhero.local. This works on most home networks automatically.

Option C — Use a Network Scanner App

Download a free app like Fing (iOS/Android) or Advanced IP Scanner (Windows). Scan your network and look for a device named guardhero or raspberrypi.

Write it down! You'll need this IP address in the next steps. Example: 192.168.1.42
5

Open the Guard Hero Dashboard

From any device on your home network, open a browser and go to:

http://[your-pi-ip-address]

Example: http://192.168.1.42

You should see the Guard Hero dashboard. From here you can view blocking stats, manage your settings, and verify that OPi-one is running correctly.

Not loading? Make sure the ethernet cable is securely connected and give the Pi another 60 seconds to fully start up, then try again.
6

Route DNS Traffic Through OPi-one

This is the step that activates protection for every device on your network. You tell your router to send all DNS requests (the system used to look up websites) through your OPi-one device, which filters out ads and trackers before they reach any device.

Log into your router's settings page and find the DNS settings. Set the Primary DNS to your Pi's IP address. Leave the Secondary DNS blank or set it to 8.8.8.8 as a fallback.

Common router brands — where to find DNS settings:

ASUSAdvanced Settings → WAN → Internet Connection → DNS Server
NetgearAdvanced → Setup → Internet Setup → DNS Address
TP-LinkAdvanced → Network → Internet → DNS Server
LinksysConnectivity → Local Network → DHCP Server → Static DNS
BT / Sky / Virgin (UK)Advanced Settings → DNS or DHCP Settings
Once saved, restart your router if prompted. All devices on your network will now have their internet traffic filtered by OPi-one — no software needed on any individual device.
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You're All Set!

OPi-one is now blocking ads and trackers for every device on your home network. Open the Guard Hero dashboard to see what's being blocked in real time.

Open DashboardBack to OPi-one

Troubleshooting

I can't find the Pi on my network

Make sure the ethernet cable is firmly plugged into both the Pi and your router. Wait 2 minutes for the Pi to fully boot, then check your router's connected devices list again.

The dashboard isn't loading

Double-check the IP address. Try opening http://guardhero.local in your browser. If that doesn't work, try the IP address directly (e.g. http://192.168.1.42).

Ads are still showing after changing DNS

Some devices cache DNS settings. Try turning your devices off and back on, or disconnecting and reconnecting them to Wi-Fi. It can take a few minutes to fully take effect.

My internet stopped working after changing DNS

Log back into your router and double-check the IP address you entered. Make sure it exactly matches your Pi's IP address. You can also temporarily set DNS back to 8.8.8.8 to restore internet while you troubleshoot.

Still stuck? Contact our support team and we'll help you out.