This video is about handmade speedometer / odometer based on Arduino for bicycle, you can find all useful links down here. This is not so benefiteful, but very interesting handmade technology project.
Servo and scale show the velocity of bike, and 7 segment display shows the distance (odometer), also ODO is stored in EEPROM, so it keep distance after system reboot.

► Page on Instructables
https://www.instructables.com/id/DIY...

► GitHub (scheme and sketch)
https://github.com/AlexGyver/EnglishP...

► Components
Arduino NANO http://ali.pub/pd9j7
Hall sensor http://ali.pub/v9li4
Servo http://ali.pub/ukaeg
Display http://ali.pub/b8fzv
5V dcdc step up http://ali.pub/u5pg9
Lithium charger http://ali.pub/zvytc

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★ My website
http://alexgyver.ru/
★ Me on GutHub
https://github.com/AlexGyver
★ Me on Instructables
https://www.instructables.com/member/...