Easy Touch Switch for Servo Activation | Microcontroller Compatible

[dmehling]

I am looking for a very simple touch switch/sensor that I will be using to activate a small servo. The sensor will be connected to a microcontroller to accomplish some very basic processing of any input received. I've been told that a capacitance switch would do the job, but I've been unable to locate one that I could easily incorporate into my project. If a capacitance switch is not an easy solution, please suggest an easier alternative.

 

[berkeman]

I like to use individual switches of the PC keyboard style. They are nice for test fixtures, etc., because they have a nice feel to them, and have very long life compared to regular pushbuttons. Like the Cherry MX Key Switch series...here are some links:

Datasheet -- http://www.cherrycorp.com/english/switches/key/pdf/keyswitch_cat.pdf

Digikey catalog page (see bottom of page) -- http://dkc3.digikey.com/PDF/T072/P1756.pdf

You can order one of hte styles that you like (tactile or not, mounting options, etc.), and also order the Keycap. I like the tactile click version myself.

 

[dlgoff]

I made a set of touch sensivite switches that uses a 5MHz oscilator using 3 nand gates of a 4011 chip and coupling ( with a ?pf cap by twisting about a 1/4 inch of 30 gauge wire together) it to the base on an NPN transistor. The base of the transistor also had a 100 Kohm resistor to ground and a small copper touch plate. When you touch the plate, the transistor becomes unsaturated. giving a high on the collector.

I worked very well. You can tune the sensivity by the number of twist on your ?pf cap.