Maker David Birgé-Cotte has opened orders for La Spirulerie's Board, an ESP32-based control board originally built for a micro-algae bioreactor and since respun into a more generically-applicable controller for 12V and 24V devices.
"I made the Spirulerie board for creating a micro-algae bioreactor (a very special aquarium)," Birgé-Cotte explains. "But during the design I realized that the problems I wanted to solve (driving 12V devices on multiple PWM channels) were not unique to my aquarium but and I could design a more generic board to [support] any 12/24V appliance!"
Built around the Espressif ESP32 microcontroller, the board includes four 12/24V control channels, Grove ports for additional sensors or other hardware, and a OneWire port pre-populated with a DS18B20 temperature sensor. A bundled "Spirulerie Interface" offers feedback and control through a 1.8" colour display and three programmable buttons.
The board was born, as the name implies, from La Spirulerie, a project to design an open-source kit for the growing and harvesting of the cyanobacteria spirulina — a popular and healthy dietary supplement. "The production kit allows you to grow spirulina simply," Birgé-Cotte explains. "Made using 3D printing and using quality materials (cork insulation, Plexiglas, etc) the kit is designed from the start to be durable, repairable, modular, and modifiable by the community."
La Spirulerie's Board is available on Tindie at $120 including the display and button kit and temperature sensor; it's also available as part of the full La Spirularie bioreactor kit on the project's website, priced at €379 (around $460). Hardware design files and software sources have been published to GitHub under the GNU General Public License 3.0.