Adrien Arias, Luke Davis, Joseph Fiol, Benjamin Gartside, Ethan Haddorff, Nicolas Porras, Kellan Wallace
Abstract : Speculos is a lightweight, cost effective, portable heliostat module that is designed to maximize precision and sunlight redirection while minimizing material use and cost, per the group’s hedgehog concept. The low cost of the unit is achieved using two stepper motors and manufacturing most of the main support structure from PETG and PLA, two low-cost thermoplastics. The module consists of a central support that functions as a protective case for the electronics used to control the motion of the mirrors. Rotation of the mirrors is achieved with two Nema-17 stepper motors, both of which rotate a shaft with a built-in gear on the azimuth and elevation axes, respectively. An ESP-32 Wrover board is used in conjunction with a Rhino PSB24-060-P switching power supply to control motors, as well as sense temperature with an SHTC3 temperature and humidity sensor to ensure safe operating conditions. Two limit switches are also incorporated into the design to allow for homing and to prevent rotation outside a desired range. The two reflective surfaces used are made of acrylic, again for their low cost and light weight. Outside of its efficient cost, low weight and high collection area, another feature of this module is its ease of assembly, since it has a relatively low number of parts. 3D printing was used frequently to simplify generation of complex contours and attachments. Through careful feature choices, our design will supply energy for up to 20 years under operating conditions to further promote principles of sustainability in energy production.