Konstantinos Paraskevas' NanoCell Aims to Deliver the Perfect ESP32-C3 Board for Battery Projects
Adding just 66.1μA to the Espressif ESP32-C3's power draw, this compact dev board offers easy Home Assistant integration.
Maker Konstantinos Paraskevas has designed a compact development board, built around the Espressif ESP32-C3 system-on-chip and targeting low-power battery-powered Internet of Things (IoT) projects: the NanoCell.
"[NanoCell is] an ESP32 development board I made to simplify the creation of small battery-powered devices for use with Home Assistant and ESPHome," Paraskevas explains of the project, which is now on board revision v2.1. "By incorporating a high-efficiency Buck-Boost converter for the 3.3V supply, an improved Battery Management System (BMS) IC, and enhanced LED indicators," he adds of the latest version, "we've optimized the board for better performance and ease of use."
The heart of the breadboard-friendly development board is Espressif's ESP32-C3, a microcontroller module which integrates a single 32-bit RISC-V core running at up to 160MHz and 400kB of on-board RAM with Wi-Fi and Bluetooth 5 Low Energy (BLE) radios for connectivity.
In the NanoCell, this module is broken out to a pair of 0.1" headers suitable for breadboard use and with additional hardware specifically tailored for battery use — including charging and monitoring of an optional lithium-polymer or lithium-ion battery, complete with protection hardware and I2C-accessible battery capacity measurement and monitoring.
According to Paraskevas' testing, the latest NanoCell revision draws just 66.1μA in idle standby with the ESP32 module powered off with a peak power draw of 464mA while charging a connected battery. "If you want to calculate the battery life of your project," Paraskevas notes, "you should expect at least 66μA of current, in addition to the current consumption of the ESP32 module."
Hardware design files for the NanoCell are available on Paraskevas' GitHub repository under the GNU General Public License 3, along with instructions for using ESPHome to integrated the board into a Home Assistant home automation setup; fully assembled units are available to order on Tindie at $14.49 each.