moving radio head unit in truck.. how to control volume?

[jeste]

I'm going to move the head unit in my truck back into the dash and put my 7" galaxy tab 2 in the front. It has an FM tuner and internet access via phones hotspot. The tablet can control everything I need to except for volume. It will be mounted behind the dash to only the screen will be in sight. Does anyone have any ideas for me to control volume on the head unit? I can probably use the remote.. assuming it will pick up being relatively out of sight. but that's not cool enough. would taking the volume knob's potentiometer off and wiring it up on the dash be too much work? I cant think of any other way of auxilary control with it. thanks.

 

[Gryd3]

I'm going to move the head unit in my truck back into the dash and put my 7" galaxy tab 2 in the front. It has an FM tuner and internet access via phones hotspot. The tablet can control everything I need to except for volume. It will be mounted behind the dash to only the screen will be in sight. Does anyone have any ideas for me to control volume on the head unit? I can probably use the remote.. assuming it will pick up being relatively out of sight. but that's not cool enough. would taking the volume knob's potentiometer off and wiring it up on the dash be too much work? I cant think of any other way of auxilary control with it. thanks.

Well... let's back up a tad.
Volume control is done one of two ways. You can adjust the gain in the head-unit, or you can adjust the strength of the signal from the Tablet. So in actuality, you can indeed adjust volume with your tablet. Turn up your head-unit to a higher volume, and turn the volume 'down' on the tablet. The downside here, is that you may here a faint hum or hiss when you are playing your audio softly, because the head-unit is still cranked pretty high. If this is out of the question due to the volume buttons being out of reach, you can simply cut the audio cord between the tablet and head unit and insert a volume knob there... This time however, the tablet and the head-unit should be set very loudly... the new volume knob will be able to decrease the volume giving you your control.
As far as relocating the volume knob is concerned... it really depends on the head unit. It can be done, but many modern head-units don't use a simple potentiometer. They typically use an alternative rotary knob that 'clicks' as it rotates... it's a digital alternative. This can be moved but will require more wires to be disconnected, lengthened and reconnected...
I very highly doubt the remote control option you mentioned will work... and here's why I think that. The remote is typically IR... which is line of sight, as soon as you put any obstruction between the remote and the head-unit's receiver, they can no longer see each other and the remote will not work.

So, the only suggestions I have are the two above... by leaving the head-unit's volume high, and reducing the volume of the signal with a new volume knob or the tablet... or you can go all out... and make a new circuit and hide an IR LED behind the tablet. Your new circuit will then pretend to be a remote control and can control the head unit from custom made buttons or dials. (This would take a fair bit of work)

 

[jeste]

This volume knob turns an unlimited amount of times. Now that you mention it, it may be alot more complicated than I thought. Adjusting the tablets volume would be the buttons on top (in landscape orientation how it will be mounted) also, the noise level with the head unit volume up is what I want to avoid. I record with a little jam band so my brain works to find and eradicate any unnecessary noise or feedback. Another thought I had is an IR repeater.. I have one for my TV remote to control a TV in the other room. It receives IR signal, converts to RF, sends it to an RF receiver and transmits back to IR. and it runs on 12VDC so no inverter spaces will be taken up. But I hate volume buttons. sometimes you get into a situation where you need to turn the volume down quickly and the knob is real easy for that.
Thanks for the input.

 

[Gryd3]

This volume knob turns an unlimited amount of times. Now that you mention it, it may be alot more complicated than I thought. Adjusting the tablets volume would be the buttons on top (in landscape orientation how it will be mounted) also, the noise level with the head unit volume up is what I want to avoid. I record with a little jam band so my brain works to find and eradicate any unnecessary noise or feedback. Another thought I had is an IR repeater.. I have one for my TV remote to control a TV in the other room. It receives IR signal, converts to RF, sends it to an RF receiver and transmits back to IR. and it runs on 12VDC so no inverter spaces will be taken up. But I hate volume buttons. sometimes you get into a situation where you need to turn the volume down quickly and the knob is real easy for that.
Thanks for the input.

Well, if you are feeling particularly brave, you could take a look at the head-unit and find out how many wires would be required for the volume knob. Note that if it has a directional or centre push button, it will make it that much harder... You can use ribbon cable from old computers (IDE cable) to make the extension.
I think you only have three options for what you want to do...
Make a circuit to emulate the remote. You can then attach a knob to this for volume control.
Use or make an IR repeater, (It could be wired, it only needs to move or repeat the signal a few centimetres.
Extend the volume knob.

If you get any decent ideas other than this, let us know. We can help you move forward.

 

[lilmatt119]

In my mind, making a new circuit and adding a knob sounds simpler....I have a feeling removing the knob from the head unit will be a real PITA, as most not only control volume but also have the center-push function and even center-push-and-hold to open yet another menu.