Quasi-passive (QP) prosthetic ankles are microprocessor-controlled devices that use small actuators to modify functionality without having to achieve the full biomimetic capabilities of fully active ankles. In addition to using lightweight actuators, QP ankles can also use relatively simple electronics systems to distribute power and control onboard devices. However, due to their relative simplicity compared to active ankles, QP ankles have fewer straightforward places to mount sensors, making state estimation more difficult. This project aims to develop a second-generation quasi-passive ankle control board that enables state estimation and terrain detection via a single onboard inertial measurement unit and strain gauge reading. The board is Arduino-based with an STM32H7 MCU, giving the system enough power to run a Kalman filter as well as a neural network-based classifier while remaining easy to use for R&D purposes, low cost, and easy to hand-assemble.