01
DESIGN
Work inside real constraints.
Select components, size circuits, compare tradeoffs, and prove that your design actually meets the requirement.
Train your
hardware judgment.
Solve realistic engineering cases. Inspect the system. Take the measurement. Make the call.
01 / THE PRACTICE
You learn by doing the work.
02
DEBUG
Follow symptoms to root cause.
Choose what to measure, interpret captures, reject weak hypotheses, and isolate the mechanism that explains the fault.
03
REVIEW
See the detail before it ships.
Inspect schematics, footprints, return paths, protection, placement, and evidence before making a release decision.
04
BRING-UP
Power the board deliberately.
Move through first power-on with bounded checks, safe sequencing, measurements, repairs, and release gates.
02 / HOW IT FEELSCloser to a lab bench
Closer to a lab bench
than a quiz.
The motor starts. The controller restarts.
The board boots and streams sensor data normally. When the 12 V motor is enabled, the motor twitches and the MCU boot banner appears again.
Compare captures at the moment of failure.
The scope shows total board current flattening at the 1.00 A source limit while 12V_IN collapses to 3.05 V and MCU_3V3 falls to 2.72 V, below the 2.75–2.88 V brownout falling range.
The timing tells the story.
NRST asserts only after the MCU rail crosses brownout. The aligned captures support supply current limiting, not firmware timing or direct reset-line coupling.
CASE 006 / MOTOR START RESETSCOPE / 40 ms
01 / SYMPTOM
12 V SOURCE1.00 A LIMIT
3V3 REGMCU
MOTOR0.42 A RUN
MOTOR ENABLEMCU RESTART
The motor starts. The controller restarts.
The board boots and streams sensor data normally. When the 12 V motor is enabled, the motor twitches and the MCU boot banner appears again.
03 / SELECTED CASES
Browse the full case library Choose a case to start.
5 V Sensor, 3.3 V MCU
Two resistors. Four requirements. Design a sensor interface that meets all of them.
Where Does the Current Come Back?
A clock trace crosses a gap in its reference plane. Follow the other half of the circuit.
It Changes Layers. What About the Return?
Identify the reference before and after a signal via, then provide a local return transition between unlike plane nets.