Motor control, power, and embedded systems
We will work through motors, motion control, power electronics, and embedded systems: write-ups, small browser tools, and open code, anchored by the Modular Motor Controller. The goal is to understand these systems well, and to leave behind something useful along the way.
Field-Oriented Control, from scratch
A series that works up from spinning magnets to a self-tuning motor drive, interactive throughout, built on the ideas behind the open Modular Motor Controller. No prior motor-control background assumed.
What field-oriented control actually does
LiveThree phase currents, one spinning magnetic field. Play with the waveforms and watch the stator vector FOC exists to aim.
Clarke & Park: turning AC into DC
LiveThe two transforms at the heart of every FOC drive. Spin the rotor and watch three wild AC currents collapse into two steady knobs: torque and flux.
The loop that runs the motor
LiveA PI controller, an R–L winding, and a step response. Tune the exact current loop that runs at 20 kHz on real silicon — and see why bandwidth is the only knob that matters.
Finding the rotor without a sensor
LiveA flux observer and a PLL estimate rotor angle from nothing but voltage and current — the trick that lets a drive spin a motor it has never seen.
From simulation to silicon
LiveThe same control core runs in CI against a virtual motor and, unchanged, on two STM32 boards driving real inverters. How the sim-first workflow catches bugs before the smoke does.
Position control on hall sensors
LiveStack a position loop on top of FOC using only the motor's hall sensors: trapezoidal references, what to do between edges, and why stiction sets the limit.
Four overlapping areas.
Motors, power, control, and the firmware around them rarely stay in their own lanes. Each area grows its own thread of notes and tools over time.
Robotics & Motion Control
Choosing and driving motors, closing the feedback loops around them, and the mechanics that carry the load — from a single actuator to a multi-axis machine.
- Stepper / BLDC / brushed DC drives
- Encoders & position feedback
- Mechatronic & CAD integration
Power Electronics
Gate drive, converters, and switching stages that move power into motors and inductive loads within their electrical and thermal limits.
- Gate driver & bootstrap design
- Buck / boost converters
- Si / SiC / GaN switching stages
Controls & Communication
Control loops from current to position, and the buses and bridges — CAN, SPI, RS-485, and Holoscan Sensor Bridge — that connect motors, sensors, and hosts.
- Current / velocity / position loops
- CAN, SPI, I2C, RS-485, UART
- Holoscan Sensor Bridge
- Sensorless & sensored control
Embedded Systems
The firmware and tooling underneath it all — bare-metal drivers, hardware bring-up, and the test rigs that keep the rest honest.
- Bare-metal & RTOS firmware
- Bring-up & hardware validation
- Production test & automation tooling
ServicesRhobic also takes on a small amount of engineering work — hardware design, embedded systems, networking, motor control, and power electronics.
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