ECE 477 Senior Design Team 7 Reliability and Safety Ben Horst Katie Taller Matt Klass Jacob Wyant

Safety and Reliability Issues ● Communication between kiosk, micro, and database is inconsistent ● Servo motors don’t function as intended ● IR sensors / load cell don’t provide reliable data ● Inventory items don’t fall correctly within the hopper ● Conveyor belt movement is uncontrolled

Components Likely to Fail ● Freescale Coldfire ● Step Down Voltage Regulator ● N Channel 12V MOSFET ● Low Dropout Regulator ● Quad Operational Amplifier

FMECA - Micro Failure No. Failure Mode Poss. Cause Failure Effects Method Detect. Criti- cality 1AOutput always high/low Software error Parts not controlled properly Obser- vation Low 1BSignal is nondeter- ministic Initializa- tion error, floating pin Parts not controlled properly Obser- vation Low

FMECA - Power Failure No. Failure Mode Poss. Cause Failure Effects Method Detect. Criti- cality 2A0VDamaged component, external short Loss of function- ality Obser- vation Low 2BCurrent draw spike Regulator failure Damage/ fry parts Obser- vation Low 2CLarge voltage spike Capacitor, large voltage ripple Motor operation not as expected Obser- vation Low

FMECA – I/O Failure No. Failure Mode Poss. Cause Failure Effects Method Detect. Criti- cality 3AMOSFET doesn’t switch D1 failure, input signal incorrect Conveyor won’t turn Obser- vation Low

Improvements ● Construct the project out of a non-flammable material ● Enclose the hoppers ● Add hand guards to the conveyor belt ● Add warning labels near moving parts