1) Assistive Button $10-35
2) Female Mono/Stereo Audio Jack 1/8 inch $3.19
3) Male 4 Conductor TRRS Audio Plug 1/8 inch $6
4) 4 wires, No Matter Length $0-$10
5) 100-100k ohm resistor $1 (RadioShack)
2) Soldering Iron
Steps 1: Gather Materials
Steps 2: Assembly
Please refer to the diagram for outline. The VR is the right channel audio wire, and WL is the left channel. R is the resistor. Vsw(+) is the input to the button (sleeve) and Vsw(-) is the output, or tip. These are all shown on the diagrams on the website.
If you cannot read a schematic well, the pictures with the colored wires may help. Black is ground, white is microphone, grey is right channel, and purple is left channel. Please reference the diagram.
After everything is soldered together, a hot glue gun was used to strengthen the connection. Also, electrical tape was placed over the exposed wires for a better look. Electrical tape was used instead of shrink wrap to be able to trouble shoot better.
Steps 3: Software Test
Download the APK file attached to this step to your phone and plug in the button you have made. Turn up your volume to 100%. The number is the sound energy of the microphone input. You should see a spike in that number and the screen should turn blue when you click the button. If this happens, you have successfully created the button!
If not, here are some trouble shooting tips:
1) Make sure your Android phone has no media audio effects on. Go to Settings -> Sound -> Media Audio Effects -> Wired Connection -> Disable Audio Effects.
2) You actually have a microphone line in to your phone
3) Media Volume is 100%
Note: This adaptation will only work for an Android phone with a microphone line-in.