Rotary Encoder as volume press button

Hi everyone.

A bit of a background so you know what I am trying to achieve and the best way to solve this;

I am installing an Android tablet in my car. Sine I'm integrating the device in to the dashboard, I won't have access to the volume buttons (up/down), which are on the side of the tablet. So, I'm going to solder 4 wires to these button and extend the volume buttons and mount them somewhere suitable.

So now, I want to use something like a [u]rotary encoder[/u] to control the volume. So in other words, every time I turn the knob right the volume up button is pressed and when I turn the volume down, the volume down button is pressed. In other words use the rotary encoder as a close switch circuit to press the buttons.

Is a rotary encoder my best option here? I don't mind programming something with an Arduino and a rotary encoder to act as a press button, however if there is a device already that can do that, I may as well use that.

I've also found this: Not sure if it will act as a close circuit for what I need for at all?

Any help is appreciated.


This encoder and board appears to be designed specifically for Sure's own amplifier boards. It's a proprietary signalling protocol.

Rotary encoders are typically simple quadrature inputs, that require two input pins on an Arduino. Assuming you're confident you can make the volume buttons do the right thing, decoding a general-purpose rotary encoder is not hard. I'm using these guys, and they're OK. Slight clicky feel. You need to add a knob of some sort yourself to make it look good:

However, I would recommend either using the on-screen volume control of most Android tablets, or using a Bluetooth control that can change the volume, or (perhaps best) wire the tablet to the car's regular stereo system, and use that for volume control. The wire-from-volume-buttons approach probably won't be super robust, because you don't get "absolute" control, only "relative" control.

@jwatte: yes you're right. Since the actual headunit is used as the amplifier in the car, I'm gonna extend the volume button on it and mount on the dashboard for the volume control. That approach will work much better for sure.

Thanks for all the input though.

Android 3.0 (Honeycomb, intended only for Tablets) is a bit of a dogs breakfast and I think most people are hoping Android 4.0 (Ice Cream Sandwich, intended for best android Tablet and Phones) will sort that out.