Quantity   Component name
1 × Arduino Nano Amazon
1 × UCTRONICS HMC5983 magnetic field sensor Amazon
1 × HTC M8 vibration motor Recovered from an old cell phone
1 × 18650 battery Recovered from somewhere
1 × TP4056 lithium battery charger Amazon
1 × Step up converter power supply charger board Amazon
1 × 3D printed enclosure Designed by yours truly