20PCS 2.5-5.5V TTP223 Capacitive Touch Switch Button Self-Lock/No-Lock Module for Arduino

It took some interesting Arduino code to get these going, but they are thin, responsive (sometimes too much which made the code more interesting), standard (I found links to how to build your own TP-223 and they were identical to these) and work very well. I would purchase again, IF I suddenly needed more than 20 to begin with.

Love these little sensor boards. Great sensitivity range (works through chicken wire laced safety window glass) where I installed a touchless doorbell that has no components mounted on the general public side of the office door. Building maintenance prefers this as no holes (screws or wires) need to be made and later filled/repaired. Love the way unit "self adjusts" the sensitivity when powered up. I thought it was NOT going to work due to the metal mesh in the window glass always caused a "contact present" capacitance load, but after 5 seconds, the IC chip adjusts the sensitivity to turn the unit "off" and then waits for a change in capacitance (finger nearness) that works through a 1/4" pane of glass. Love these little units !

Used these on a touch sensitive art project. If you scrape off some of the "Touch Here" area, you can solder a wire onto it and run it to a piece of aluminum foil to expand the sensitivity area (If you want. :-) )!

These really work great. Your finger doesn't even have to touch the surface. When your finger gets about an 1/8 of an inch away, the sensor will trigger. I placed the sensor underneath a 1/16" thick clear plastic and it still works. I like the red led that comes on automatically indicating the sensor is detecting your finger. If you are using two or more of these, be to space them physically a bit apart from each other so you don't inadvertently cause two or more of them to trigger accidentally. I lowered 1 star because the package does not include the pins. I lowered a 2nd star since I am forced to solder the pins myself.

All sensors are working as expected.

These are basic and just work. I use some to be momentary switch and others to be latching on and off switches. I can’t build these myself for cheaper so the choice is easy. For me they activate a little more than 1/4” away with my finger. Have not put them behind an materials for testing how thick something can be and still work.