Touch Sensor module:
Based on the touch sensor chip TTP223B, the module is capacitive touch switch module.
Normally it outputs low and it is at low power state.
Only when you touch the appropriate location, it will output high.

Touch Sensor (T) module:
Based on a touch detection IC (TTP223-BA6), and the IC is in toggle mode;
Power on, the module output low level (You can modify the initial level by the toggle switch) and the mode is low power mode;
Touch related position with finger, module will output opposite level ( ie, the original output is high, and then output is low after touch).
If the module is mounted in the surfaces of non-metallic materials such as plastic, glass, acrylic, you can make the keys hidden in the walls and desks.
Features:
- Funny and easy to use, can replace the traditional button or self-locking switch
- Increase the filter circuit, the signal output stable
- Low power consumption
- Working voltage: 2~5.2V DC