RPM Jack Counter

An RPM counter that uses the audio jack as input

Requirements

To compile this project you will need a machine running Linux, Windows or macOS and the latest flutter framework.

Dependencies

This project depends on:

• sound_stream from casperpas link here.
• markdown from dart.dev link here.
• flutter_widget_from_html from daohoangson.com link here.
• in_app_purchase from flutter.dev link here.
• shared_preferences from flutter.dev link here.
• permission_handler from baseflow.com link here.
• flutter_svg from dnfield.dev link here.
• provider from dash-overflow.net link here.
• path_provider from flutter.dev link here.
• mic_stream from Aaron Alef link here.
• cupertino_icons from flutter.dev link here.
• google_fonts from material.io link here.

Minimum requirements

I have just tested it on a Galaxy A40 and Galaxy S10 (Hong Kong version). No further testing has been performed. I expect it to work pretty well on any other device that supports flutter, as it uses pretty standard packages, as well as on iOS devices, as long as it has a headphone jack. It should work also over bluetooth, but you'd need to send the pulses through bluetooth audio, maybe picking a cheap bluetooth broadcaster through Amazon, like this ones:

• EasyULT Transmisor.
• ELEGIANT Transmisor.

This is NOT and endorsement for ANY product, nor any recommendation whatsoever. This should IN THEORY work, though.

Sadly I don't own any iOS device, so unless you can give me one, I won't be able to test it for you.

How it works

My bike sends the information through an audio jack cable. Each time a revolution is performed, an audio pulse is sent through the headphone jack. We receive the input from the mic using sound_stream and count how many peaks are reached per second. The information will be passed to a method that will turn those numbers into revolutions/minute (RPM).

As simple as that.