Large Object Capacitive Touch

[midazoblam]

Newbie here. I'm using an ESP32 to make an automated reading light that goes on when the person sits in a specific seat on a couch next to a light. There's a car seat pressure sensor in the cough pillow which detects presence, and the ESP32 can connect directly to a kasa smart plug that the light is plugged into. All of that works great. We also want to be able to use the light even when someone isn't sitting in that seat. The smart plug itself is out of reach, and we don't want guests to need access to the kasa app to turn the light on.

I need help creating an unobtrusive way to detect when the user manually wants the light on. At first I thought I'd connect the large metal light to a capacitive touch pin, but the output drops to 6 when untouched, 5 when touched, and there's just too much noise to make this reliable. Putting in a resistor (any size) with a 10 uF capacitor in parallel seems to bring the signal to a static 0. Any advice on how to either 1) make the capacitive touch sensor work well with a large metal object, or 2) how to otherwise creatively allow for a manual on/off?

TYIA

[liaifat85]

ESP32 has a built-in capacitive touch sensor. ESP32 Board has 10 built-in capacitive touch pins, which generate an electrical signal when someone touches these pins. These ESP32 touch pins are normally used to wake up the board from deep sleep mode. These touch pins are also used to replace the normal mechanical buttons with touch pads, improving the presentation of the IoT projects.
source: https://www.theengineeringprojects.com/ ... ensor.html
However, using capacitive touch sensing for a large metal object like a light might indeed introduce noise and reliability issues due to the size and conductivity of the metal.
Instead of capacitive touch sensing, you could use a proximity sensor. These sensors can detect the presence of a hand or object near them without direct contact. There are various types available, such as infrared (IR) or ultrasonic sensors, which you can explore based on your requirements and the design constraints.