Best practice to use a JS function in ionic framework

Hello, I am pretty new in ionic framework and angular JS. Currently I am working on developing a mobile app which will use mqtt protocol for data exchange. I have already written a cordova plugin for this mqtt service and also designed a very basic UI for that. What I intend to know from this forum is the preferred convention of calling a function which I have written in java script.
One of the views which I have defined in app.js is Home which contains the following few lines as part of its template.

<ion-content class="padding">
    <div class="list card">
        <div class="item item-divider">MAC Address</div>
        <div class="item item-body">
            <div class="item item-input-inset">
            <label class="item-input-wrapper">
                <input type="text" placeholder="MAC Address" ng-model="??">
            <a class="button button-small icon ion-bluetooth button-positive" ng-click="??" >

I want to use the value from the text-field and pass that as an argument argument to the function “” which is defined under a JS file named mqttPlugin.js.
I know my question is very basic, but I would appreciate if someone helps me with this. I know that I would have to modify the controller for the view home to make room for such a change, but since I am not familiar with dependency injection, I would appreciate some help.