Cerelog ESP-EEG8-Channel Brain Computer Interface Circuit Board

The Cerelog ESP-EEG was designed from the ground up to close a gap that has existed in the low-cost biosignal hardware space for years: boards that use the right ADC chip but cut corners on every surrounding circuit decision. The ADS1299 is a genuine research-grade component — the same part found in instruments costing tens of thousands of dollars — yet many low-cost implementations treat it as a commodity part and ignore the reference design guidance that makes it perform well. The ESP-EEG was built by following that guidance closely, particularly around the bias drive topology and power supply filtering, rather than around minimizing BOM cost.

Choosing the ESP32 as the host microcontroller was deliberate. It handles SPI communication with the ADS1299 reliably over USB-C at the board's operating sample rate, while the onboard WiFi radio enables LSL streaming to the OpenBCI GUI fork and provides a path to expanded wireless functionality over time. The ESP32-WROOM-DA also includes Bluetooth 4.2/BLE at the hardware level, making it available to product developers building custom firmware — the board ships with USB-C firmware pre-loaded, and no Bluetooth firmware implementation is included by default. As with any microcontroller-based acquisition system, some data throttling applies and occasional packet loss is possible depending on the host environment. The USB-C interface handles the majority of current workflows reliably, and the LIPO charging circuit means the board can be untethered from a computer during a recording session when battery operation is preferred.

From a software standpoint, the decision to integrate with BrainFlow and publish a fork of the OpenBCI GUI rather than building a proprietary application reflects a philosophy of meeting researchers where they already are. Most academic labs already have Python environments with NumPy, SciPy, and MNE installed. Rather than asking users to learn a new toolchain, the ESP-EEG plugs into the infrastructure they already trust. The BrainFlow integration in particular means that any script written for another BrainFlow-compatible board can be adapted to work with the ESP-EEG with minimal modification.

The open-source firmware and published schematics serve a dual purpose: they allow technically capable users to audit exactly what the hardware is doing, and they create a foundation for community contributions. Several community-built tools — including the PhantomLoop neural decoder interface — have already emerged from users who were able to examine the data protocol directly. The Discord community exists specifically to lower the barrier for researchers who are domain experts in neuroscience or BCI but are not hardware engineers, connecting them with users who can help with setup questions quickly.

The board is positioned as a research instrument rather than a consumer product, and that distinction matters practically. It ships without a case by default because many research applications call for integration into a custom headset, enclosure, or experimental rig where a generic case would just get removed. STL files for a printable reference enclosure are available in the GitHub repository for users who want a standalone housing without designing their own.