Fix 16-bit int overflow in NonBlocking example move distance#142
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100 * MOTOR_STEPS * MICROSTEPS (= 320000) was computed in int arithmetic, which overflows on 16-bit AVR before promotion to the long parameter of startMove(), producing a negative distance that reverses the move direction on Uno-class boards (gcc flagged it with -Woverflow). Use 100L so the whole expression is evaluated as long. Also fixed the commented-out startRotate() line (100 * 360 = 36000 overflows too) and audited the other examples: all remaining arithmetic in move()/startMove()/rotate() arguments stays within int range (largest is UnitTest's 200 * 128 = 25600). Verified: make NonBlocking.hex TARGET=arduino:avr:uno builds clean with --warnings all (the previous -Woverflow warning is gone). Agent: claude-fable-5 (Claude Code 2.1.153); max context and thinking level not exposed to the agent Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Summary
examples/NonBlocking/NonBlocking.inocomputed the move distance as100 * MOTOR_STEPS * MICROSTEPS(= 320,000) inintarithmetic. On 16-bit AVR this overflows before promotion tostartMove()'slongparameter, yielding a negative value that reverses the move direction on Uno-class boards. gcc was already flagging it with-Woverflow. Fixed with100Lso the expression is evaluated aslong; also fixed the commented-outstartRotate(100 * 360)alternative (36,000 overflows too).Audit
Checked all other example sketches for arithmetic in
move()/startMove()/startRotate()/rotate()arguments — everything else stays withinintrange (largest is UnitTest'sSTEPS * microstep= 200 × 128 = 25,600).Testing
make NonBlocking.hex TARGET=arduino:avr:unobuilds clean with--warnings all; the previous-Woverflowwarning is gone. Behavior on 32-bit targets is unchanged.Agent: claude-fable-5 (Claude Code 2.1.153); max context and thinking level not exposed to the agent
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