Switch that triggers at 2V

Question

I have a piece of electronics that acts as a event sensor and its trigger voltage starts around 3.3V. Lets say that I want to little bit hack this device and hook it up to a button that is on other device. I found out that when I press this button, LED will turn on and there is about 2.3V that can be measured one resistor. If button is pressed again, LED will turn of and there will be 0V.

I want to make this button as an input to the event sensor, but 2.3V is too low voltage to trigger it. I could use Arduino that would read input voltage and I can define trigger threshold there. But I want it to be simple electronics, passive and efficient. Maybe MOSFET or BJT? Can someone give me advice how to do it?

Thank you

Answer 1

^{simulate this circuit – Schematic created using CircuitLab}

This is an inverting switch. R values can be changed

Answer 2

Use a voltage divider to create a desired trigger level voltage and use a comparator to deliver full (3.3V for example) voltage when that voltage level is reached.