Kayra

Three configuration files belong together

The host, controller and simulation use an 18-value servo vector. The documented map assigns leg channels first, then arms, pelvis and head, with channels 14 and 15 unused. This is a software interface, not evidence of 18 independently verified mechanical degrees of freedom. Arm and pelvis assignments are explicitly unverified, and limits are derived from stored poses plus a margin rather than measured mechanical stops. [S005] [S006]

The controller expects servoConfig.json, servoControl.json and servoMap.json. The documentation says it still runs when the map is missing but does not enforce servo limits. Its identification tool can move individual channels and deliberately bypasses software limits. These details make configuration and physical calibration substantive work, rather than a file-copy step that proves the mechanism is ready. No servo was moved or calibrated in this review. [S006]

The wiring instructions assume a modified board

The wiring page describes a Servo 2040 with its USB/external-power linking trace already cut. In that configuration, the servo supply does not power the controller logic, so the documented untethered setup has a separate 5 V logic supply. Do not assume these instructions describe an untouched board. The same page still leaves the exact servo model, operating voltage, battery and mounting/charging procedure unfinished. This review does not substitute a power recommendation for those missing choices. [S005]

The documented host route uses Python on Linux and USB serial; the body uses MicroPython controller code and a BNO055 IMU. Stored poses can run untethered through the user button, while the host pose editor sends commands over serial. That is a concrete control workflow, but its presence is not a tested balancing or locomotion result. [S005] [S006]

Use simulation as a separate development surface

The MuJoCo directory contains XML models that reference repository STL files and discusses the closed-loop geometry of the leg mechanism. The software guide gives separate host and simulation requirements. Model exploration can help inspect geometry and control interfaces, but this publication has not installed the environment or compared simulated motion with a physical Kayra. [S006] [S007]

The repository carries BSD-3-Clause. That license is recorded for its design and software sources; it does not replace the terms of purchased electronics, board firmware or independent dependencies. No complete current build budget, manufacturing validation or physical performance result is claimed here. [S003] [S004] [S005]