Recently I have been thinking much about home automation and one of the things that came to me was to replace my mechanical switches with a smarter one. In this project I will be explaining to us an easy but effective way of designing a smart touch switch using TTP223 capacitive touch module. The smart touch switch in this project did not use any microcontroller, so we don’t need to write any program, which makes it easier and more cost effective. You can see other of our previous home automation projects here.
Required components
| TTP223 touch module x 1 | Buy here |
| 1 Channel Relay Module x1 | Buy here |
| AC – DC (220v-5v) module x1 | Buy here |
| Green Light emitting diodes x1 | |
| 150ohms fixed value carbon resistor | Buy here |
| Solderless Prototype board and wires | Buy here |
The schematic diagram
TTP223 touch module
The system uses the TTP223 module. In the heart of the module is the TTP223B integrated circuit. The TTP223 is a touch pad detector IC which offers 1 touch key. The touching detection IC is designed for replacing traditional direct button key with diverse pad size. The module have 4 different modes that can be configured using 2 jumpers A and B. You can download the TTP223 datasheet here.
Configurations:
A Not connected = ACTIVE HIGH
A Connected = ACTIVE LOW
B Not Connected = Momentary switch
B Connected = Toggle switch
By default the jumpers are not connected, which means that the module will generate an ACTIVE HIGH signal through the I/O pin and will act as a momentary switch. But in our circuit, we want the module to generate an ACTIVE HIGH signal that will be fed to the Relay module and also act as a toggle switch, so we will connect the B jumper on the module with a little amount of lead.
1 Channel Relay module
A 1-channels 5v relay is used in the circuit to switch the load ON or OFF. The relay are capable of driving 250v/10A AC load. The Module has 3 pins marked -, + and S. – and + pins are the power supply source of the module. S is the signal pin.
The relay module used in this project is an Active HIGH. Which means the relay will be energized when a HIGH signal is sent to the Signal pin (S) of the relay module. The signal (S) pin of the relay module is connected to the output (I/O) pin of the TTP223 module.
Power Supply Module
220v-5v isolated power supply module is used to power the whole system; relay module and the TTP223 module. Positive (+) and negative (-) of the power supply module connects to the positive / negative (+ / – and VCC / GND) of the modules respectively. Life (L) and neutral (N) connects to AC mains supply.
Application of the System
The smart switch can be used anywhere to switch a load ON/OFF as long as the load is within the capability of the relays. The smart switch can be used at home or office to control appliances or lighting points or even incorporated in any gadget to give it that smart tap-to-switch feeling.
Watch it work
Thank you for reading through. if you like the project, you can share it with your friends using the social media buttons and if you have built the system and/or have any question, tell us through the comment box below.