I programmed a $7 ESP32-S3 board to block all computer's web ads - and it took just minutes

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The rising costs of Raspberry Pi boards have prompted exploration of cheaper alternatives. A recent project required an ad-block solution, and instead of reaching for a Raspberry Pi, the author considered a more affordable option: the ESP32 board. Specifically, the ESP32-S3 board, which can be purchased for under $10.

The ESP32-S3 board features a dual-core Tensilica Xtensa LX7 32-bit processor, 520 KB of RAM, and up to 16MB of flash storage. In contrast, a Raspberry Pi 5 boasts a 2.4 GHz quad-core Arm Cortex-A76 64-bit chip, gigabytes of RAM, and support for microSD or fast NVMe SSD storage. The ESP32 board uses milliwatts of power, whereas a Pi 5 can consume up to 12 W.

For the ad-block project, the author chose the ESP32-S3 board with 8MB of PSRAM. This board is faster and more efficient, necessary for running the ad-block software. The cheapest option is purchasing a 3-pack for $20.

Setting up the ESP32-S3 board for ad-blocking involves loading the ESP32_AdBlocker software using the Arduino IDE utility. The process is straightforward: configure the Arduino IDE, connect the board to the PC, and upload the software. The ESP32-S3 board functions as a network appliance after the software is loaded.

It initially starts in Wi-Fi access point mode, allowing the user to connect and configure the board by providing the Wi-Fi SSID and password. The user then specifies the URL of the blocklist to use. To complete the setup, devices must be configured to send DNS requests to the ESP32 board.