Capacitive Touch Switch (TPP223)

Smart Home Integrations SmartThings
1

I'm attempting to use a capacitive touch switch with the Konnected development board. This is my first use of this type of device and need some guidance on its capabilities and how to integrate it into the Konnected development board using the standard Konnect firmware and DH. Since there isn't a Konnected predefined DH for a capacitive switch I've used momentary, switch, blink/beep, smoke ... without any success.

Based on the testing I conducted with this capacitive switch on a ESP8266 using a Arduino sketch I wrote this device can be read from the ESP8266. The only thing unusual about the Arduino sketch was defining the digital input pin for this device as an "INPUT_PULLUP".

I'm seeking some suggestions on how to integrate this TTP223 switch with a Konnect Development board. I suspect the current set of standard Konnect device handlers don't support this device. I

TTP223 Capacitive SwitchTTP223 Capacitive Switch

Thanks in advance for any suggestions or solutions.


Greg

2

Gesh, guess I should do more testing before posting. 

After sleeping on it I ran a few more tests this morning and discovered a feature I hadn't noticed before when defining an open/closed switch in the Smartthings DH. You can define the switch as either Normally Open or Normally Closed. 


Setup: 

Konnected Development Boards (ESP8266/NodeMCU; FW 2.2.6)

TPP223 Capacitive Switch - Power 3.3V 

Test breadboard with 3.3 and 5.0 volt power

Configuration: Pin D6 - Definded as an Open/Closed Switch, Normally Closed 

Tests: 

Condition 1: Measure voltage on Pin D6 with capacitive switch inactive (no touch)

Results 1: Voltage on Pin D6 = 0.0 Volts DC; Smartthings reports switch OPEN


Conditions 2: Measure volatage on Pin D6 with capactive switch activated (touched)

Results 2: Voltage on Pin D6 = 2.8 Volts DC; Smartthings reports switch CLOSED. 


What has me puzzled is with the switch inactivated (no touch) and Pin D6 with 0.0 Volts why this isn't considered a Normally Open switch. Does the logic level on Pin D6 have something to do with it? What am I missing?


-Greg