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ZDNET's key takeaways

A low-cost $7 board handles ad blocking duties effectively.
It functions as a DNS sinkhole to filter ads prior to loading.
Alternatives range from Raspberry Pi setups to dedicated hardware purchases.

Necessity drives innovation, and escalating Raspberry Pi prices have pushed me toward economical alternatives that may suit specific tasks better. While the Pi excels in many roles across its nearly 15-year history, it often exceeds requirements for simpler projects.

Recently I sought an ad-blocking tool due to constrained bandwidth rather than aversion to ads themselves. Instinct led me toward a Raspberry Pi until current pricing prompted reconsideration.

Plans involved running PiHole, yet recall of an ESP32-based ad-blocking initiative offered a path forward with boards available below $10.

Exploring the ESP32-S3 option

Significant contrasts exist between a Raspberry Pi 5 and an ESP32-S3 board. The Pi 5 features a 2.4 GHz quad-core Arm Cortex-A76 processor, ample RAM, and support for microSD or NVMe storage. By comparison the ESP32-S3 employs a dual-core Tensilica Xtensa LX7 32-bit chip reaching 240 MHz, 520 KB RAM, and up to 16 MB flash. Power draw differs markedly too, with the Pi 5 consuming up to 12 W versus milliwatts for the ESP32.

This project favors the ESP32 despite certain trade-offs discussed below.

Required components

An ESP32-S3 board with 8 MB PSRAM is essential, as the 4 MB variant introduces limitations. This model delivers improved speed and efficiency needed for ad-blocking tasks. Boards are obtainable economically in three-packs around $20.

Initial impressions highlight the board's miniature size, confirming it operates as a fully functional computer. A USB-C cable handles connectivity and power, eliminating any microSD requirement.

Software needs include the ESP32_AdBlocker project alongside the Arduino IDE for installation. Setup involves configuring the IDE for ESP32 support, loading the code, linking the board, and initiating upload. Connection uses the COM or USB/Native port on the right side when oriented with ports downward.

Common hurdles involve charge-only cables or IDE configuration tweaks, with recommended settings available for reference. Cases can be purchased, 3D-printed, or improvised using electrical tape or shrink tubing.

Board initialization process

After software loading the ESP32 operates as a network device. Initial startup creates a Wi-Fi access point named ESP32_Adblocker followed by unique characters. Connection to this network allows access via 192.168.4.1 to input home router credentials.

Subsequent reboot permits entry of a chosen blocklist URL from available repositories. Devices must then route DNS queries to the board's address, typically by updating router settings accordingly.

Operational mechanics explained

URL entry triggers DNS lookups to resolve server locations. The ESP32 intercepts these requests, checking against a blocklist of ad domains. Matches return an unreachable address to prevent loading, while valid requests forward onward.

This creates an efficient DNS sinkhole for most online advertisements, conserving bandwidth.

Limitations include incompatibility with YouTube ads sharing video servers and lack of IPv6 support. Nonetheless the approach demonstrates substantial capability from an under-$10 device.

Alternative considerations

For short-term bandwidth relief this method delivers results alongside engaging hands-on experience. Longer-term needs might favor a Raspberry Pi Zero 2 W with PiHole, elevating costs to roughly $15 plus storage. Other paths encompass dedicated machines, virtual instances, or prebuilt appliances, though each varies by use case.