Capacitive touch modules are built into a lot of devices and are now really easy to integrate into projects. These little modules are digital switches/buttons that can be built into things and even sense through tabletops. They can also be configured to output a high or low signal on activation and to be latching like a switch, or momentary like a push button.
The module has three connections for power and one output. They use the TTP223 control chip which has a couple of selectable options.
There are two solderable jumper selectors on the electronics side of the touch module. these are labelled ‘A’ and ‘B’.
There is a good tutorial here where this quick guide information came from.
‘A’ controls the output when activated from either high (positive voltage) or low (no voltage).
‘B’ selects if the module is momentary (only outputting when being touched) or latching (one touch to turn on the output, another to turn it off).
When selecting the jumpers, a small blob of solder can be used to connect both of the required jumper pads together.
| Switch Operation | A | B |
| Momentary, touch HIGH | blank | blank |
| Momentary, touch LOW | Connected | blank |
| Latching, touch HIGH | blank | Connected |
| Latching, touch LOW | Connected | Connected |
