Balancerator: two-servo power fault

second servo added → sweep turned into vibration / continuous rotation??
separate supplies got the test working. need to measure the power behavior instead of leaving the explanation at 'probably draw/reset'

• symptom: after adding the second motor, the sweep example failed. The notebook describes vibration followed by continuous rotation rather than the expected sweep.

• debug sequence: check logged program logic, configured ports and baud-rate assumptions; then separate the Arduino and servo power supplies. The separate-supply test is recorded as successful. Power draw/reset behavior was the proposed explanation, not an electrically measured diagnosis.

• code reference: Arduino Servo.h sweep/knob examples. The notebook mixes servo-control and software-serial terminology; do not copy that wording into a wiring specification without checking the actual motor interface.

• review questions: measure supply behavior during simultaneous movement; confirm the actual signal wiring and power-return arrangement from the hardware. Keep supply changes and firmware changes separately logged so the fix is reproducible.

Balancerator wiring and pinout diagram.