Connect with stackmat like hardware timers

Some of hardware timers are able to output their timing data by 2.5mm cable. For most of these timers, csTimer is able to decode the data.

Here's a diagram how a hardware timer works with csTimer.

[ Hardware timer ] --> (2.5mm to 3.5mm adapter) --> [ Internal sound card --> Browser --> csTimer ]

However, the signal from hardware timer might be distorted. And for most cases, the distortion is due to unexpected behaviour of the sound card and the browser, e.g. noise/echo cancellation procedure. Especially for mobile devices, there is few options to affect the behaviour of the system and browser.

To fix these problems, we find a robust solution with aid of external sound card and native application, whose diagram is as follows.

[ Hardware timer ] --> (2.5mm to 3.5mm adapter) --> [ External sound card ] --> (USB/Type C/etc.) --> [ Native app --> csTimer ]

A beta version of the app is available at cstimer_stackmat.apk