index of all pages
autonomy
- AI-Enabled Mid-Range Strike Drones (Azov Unit Perspective) An operational view of deep-strike drones: field modification labs, terminal-only AI guidance, and the argument that adaptation speed, not resources, is the real force multiplier.
- Ukraine AI Terminal-Phase Drone Strikes AI scoped to the terminal dive only - GPS-denied terrain matching, adversarial-hardened target recognition, and final-approach guidance - with the human in the loop for the rest of the mission.
- VLA Architecture: Vision-Language-Action Models for Robotics Vision-Language-Action model architecture - a large VLM backbone paired with a small real-time action expert, as used by NVIDIA GR00T N1 and Physical Intelligence's pi-zero.
embedded-systems
- Cortex-M Bare-Metal Boot What happens between power-on and main on a Cortex-M - stack-pointer init, data and bss setup, and the hosted-runtime preamble you write yourself with no OS or libc.
- FreeRTOS Task Control Block (TCB) The FreeRTOS Task Control Block - the per-task struct the scheduler uses to track, save, and restore a task, and how it relates to the task's separate stack.
- Unix signals Unix signals as asynchronous, preemptive notification to a process - the same suspend-save-jump model as a hardware interrupt, one layer up.
guidance-control
- Metaheuristic PID Tuning for Quadcopter Stabilization A 2021 study comparing genetic-algorithm, crow-search, and particle-swarm tuning against Ziegler-Nichols for auto-tuning quadcopter PID gains.
- Quadcopter Flight Physics Overview The fundamental physics of quadcopter flight - forces, stability, and the torque and yaw control principles that control theory and simulation build on.
- Thrust vector from attitude angles Mapping attitude angles to a body thrust vector in the NED frame - how a desired orientation becomes the direction the rotors push.
- TiltDrone: Fully-Actuated Tilting Quadrotor Platform TiltDrone, a fully-actuated quadrotor whose biaxial tilting rotors decouple translation from rotation, giving independent control of all six degrees of freedom.
sensing
- I2C Protocol The I2C two-wire, open-drain, master-slave bus that connects sensors like the MPU-6050 to a microcontroller on the same board.
- I2C Pull-up Resistors Why I2C needs pull-up resistors on SDA and SCL, how to size them, and what breaks when they are missing or wrong.
- MPU-6050: MEMS IMU The MPU-6050 MEMS IMU: a 3-axis accelerometer and gyroscope on one die, the six raw measurements a complementary or Kalman filter fuses into attitude.
state-estimation
- Body rate cross-coupling and when you can ignore it How measured body rates couple into Euler-angle rates, and the conditions under which the cross-coupling terms can be safely ignored.
- Complementary filter for attitude estimation Fusing a drifting gyro and a noisy accelerometer into one roll/pitch estimate by splitting the frequency domain - the simplest useful attitude filter.
- Quaternion kinematics for the error-state Kalman filter A working guide to Joan Sola's quaternion kinematics for the error-state Kalman filter - the reference for fusing IMU data with external corrections in an ESKF/VIO estimator.
- Roll and pitch from accelerometer Deriving roll and pitch from the accelerometer out of the rotation matrix, so the formulas - and their signs - are never guesswork.
- Rotating coordinate frames and the transport theorem Rotating frames and the transport theorem - the NED-frame conventions and derivative rules behind body-to-world rotation in a flight estimator.