5V Capacitive Touch Sensor Turn on 12VLED Light

I'm a general handyman, I can operate a crane, wire a house, replace a head gasket... Now I want to add lamp builder. 40 years ago I bought a Lamp that had a plant around the base.. When you touch the plant leaf, it turns on the light.. touch the leaf again it turns it off.
This is a live plant and it has been changed over the years. This year it stopped working and I took it apart. there is a wire that runs to a copper foil that is under the soil... I replaced the foil and re-soldered the wire and it's great again..
Now my granddaughter (19 months) loves to play with it so I wanted to build her one..
I tried using a replacement touch lamp switch but it would only work when touching the soil or the stems of the plant, close to the soil.. not sensitive enough.. So rethinking it I want to try using a 5V Capacitive Touch Sensor (Phidgets) to turn on and off a 12V LED Light bulb.

In my limited understanding, I start with a 12VDC power supply, run that to some type of controller that will send 5VDC to the sensor and send 12V to feed a relay. The 5V signal back to the relay switches the relay on and the 12V goes through to the light.
I fear I must be wrong because the relay needs to switch the light on... and have it stay on until it's touched again and then go off.. I think this would only work if you kept holding it..

Space is limited so, do I need a controller? With a controller do I need a relay? Should I use an Arduino? Do they have different sizes? How would you attack this?

Thank you for your kindness!

I would like to make a few points learned the "hard way." The "hard way" was designing, building, and coding and continually testing a system to enable switching the music (iTunes from my PC) between 2 pairs of speakers.

The latching-switch (effectively DPDT) is the first task. This part was tested without the relay and its portion of the work. This portion would be pure Arduino (bread-board), with 2 LEDs to indicate switch states.

Your control circuitry would switch an SPST relay on or off to turn the lamp on or off. You can use a 5vdc SPST relay. A 12VDC component should not be powered through the Arduino circuit. I burned out two (I am slow to learn) Arduino UNOs before I realised that the 12 volt push was too harsh.

Even with the 5VCD relay I was spooked enough to use an "OPTOCONTROL" to switch the relay. The optocontrol takes a light-current signal (digital-write HIGH) to trigger a switching transistor in the same case. If you use a 12-volt relay I know that you will need the Optocontrol.

I hope that this helps you. Cheers. Tom Kane / Vancouver, BC, Canada

Thanks Tom. I'm definitely new to this but I'm older now and have some time on my hands to learn.. Watching Paul McWhorter's tutorials is very helpful , as is finding out that 12V is disagreeable with the Arduino.
Still I now need to look up DPDT, SPST, latch switching and OPTOCONTROL.
I remember when I went into teaching.. the jargon was new and needed to be learned.. feeling that again.. Thank you for your input!

What you need for this is a TTP223 module, dirt cheap and you need no Arduino or toggle circuit as it does it all for you. You do still need the relay module to switch the lamp.

](1 Channel Capacitive Touch Module - TTP223 [4481] : Sunrom Electronics)
Note that you solder over jumper "B" to cause it to toggle between "on" and "off" each time the touch pad is touched, your touch pad (plant) you connect to the top right connection.

Now all you have to figure is what relay board to use. :grinning: