The easiest method is to exploit the headset jack that's currently present on the telephone! Now like every technology job there are limits about the requirements of exactly what this port can perform.
A normal headphone jack will generally just pay for the frequency ranges which a human can listen to (20 -- 20,000 Hz). This looks like a limited selection but for many sensors and software that this is really a fairly broad selection. A fantastic example program is for medical detectors like EKG, EEG and EMG. These signs do not have parts much over 100 Hz in the most!
The wise phone Signal Generator Supplier could be constructed for under $15! The hardware includes one stereo 3.5 millimeter headphone plug, a few wire and optionally three alligator clips to attach the High quality Signal Generator into the test apparatus. The headphone jack contains a left and right channel along with a floor. The significant metal tab at the base is your floor with the red and green wires being connected to the left and right channels . When the headset jack is soldered, it may be shut and the alligator results can be attached either via the set screw based on the sort of connector chosen.