Cell Phone Interface for Goldwings
This project uses a hands free unit that comes with most cell phones and requires one to make three connections to the wiring under the left fairing pocket near the plug for the headset, and three connections to a hands free unit for your particular phone. It does require a bit of electronic and soldering expertise. If you are not comfortable making these connections read no further and order a plug and play unit from one of the many fine vendors. The connections at the top of the schematic below are the ones on the Goldwing. You can see a pinout in the image at the bottom of the page.
The ground is the simplest connection. Connect a wire from the shield of the mic inputs to get a good ground between the Goldwing and the hands free unit. Make a similar connection to pin 3 from the speaker lead.
The second connection is from the mic input of the Goldwing (pin 1) to the audio from the hands free unit. Cut off the ear bud and discard it. Connect the shield to ground and connect the center conductor to the 10 k resistor. Don't forget the .01 mfd capacitor. The audio from the hands free unit supplies audio to your headset mic input to allow you to hear the phone. If you like you may substitute a 50 k potentiometer for the 10 k resistor. This will give you a volume control.
The third connection is the most difficult. It is from the Goldwing to supply your audio to the cell phone allowing the person you are talking to to hear you. Ordinarily you would speak into the built in mic to talk if you were using the hands free unit in a car. You will be talking into your mic on your helmet headset. Take the small unit apart that contains the mic element. You should be able to pry it apart with a small knife blade or screwdriver. Locate the mic element pins. There will be two of them on the underside of the element. They will protrude out the bottom side of the board. Heat them with a small soldering iron. Do not use a soldering gun. This will be a surface mount board. Use as little heat as possible to remove the element. Using a multimeter determine which pin is the ground. The ground side will show zero ohms to ground. The other pin will show a higher resistance. This is the one you want. Connect the 100 k resistor (or small wire) to this point, going thru the .01 mfdf capacitor and on to pin 4 or 5. You can use either one. Either one will supply audio to the mic input of the hands free unit. Note: If you are lucky enough to have a hands free unit with a wire coming out of the unit with the mic on the end of it this will greatly simplify this step of construction. Cut off the microphone and simply use the ground and mic connection.
This has been tested and works very well. The hands free unit is already set up to work with your cell phone and to operate in the noisy environment of computer noise, radio freq, and other generated noises. Be sure and make good connections for the shielded wires to the proper connections on the Goldwing. All you need to do is make the connections along with the few parts. The two capacitors and the 10 k and 100 k resistors may be of quite a range of different values. Different headsets will have different impedance values. If your volume levels are too low or high don't give up. Substitute different values for the resistors. Any voltage rating for the components will work because you are only working with low level audio signals.
My cell phone is a Motorola Razr. When I plug in the cable from the hands free unit it automatically goes to auto answer mode. When I unplug it to place it back in my pocket it goes back to normal mode. I am assuming most cell phones operate in a similar manner. The audio is very crisp and natural. The person on the landline hears a bit of an echo but most say it is not bothersome. If you have a co-rider she (or he) can hear and talk at the same time as you.
If you have questions email me at Mick*LindleyOnline.com. I will be glad to help you out. Star is substituted for @ sign to thwart email harvesters. This is a great project that is going to save you about $300.00. Have fun, Mick
The connections on the bottom are to be made to a hands free interface that comes with most cell phones. If you don't have one you can get one for 15 to 25 dollars, or much less on eBay. The hands free unit is already set up to operate in a mobile environment we find in cars as well as motorcycles.
The picture below is courtesy of Steve Saunders Goldwing page.
Click on the image to go there.
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