Detecting a sensor when it disconnects

Projects General Guidance
1

hi, i am on a project. i am using a "seat occupancy sensor" which has 10M ohm resistance when no one sits on it. if anyone sits it has around 2k ohm depending on how much pressure on it.

I can use this sensor perfectly. but now i want to detect if sensor is connected properly or there is a broken wire between sensor and Arduino Nano. for this purpose i am planning the add 500k ohm paralel the sensor and so i can read around "20" out of 1023 with analogRead() function. and if i read below 20 this means the cable is broken.

is my approach correct? if yes my resistor values are ok? if no what is ur recommendation thank you.

circuit

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2

So easy to try!

3

i tried it worked. but i am not sure if it is correct way to do it or not. i mean i never saw adding resistor to a sensor. it is claver or stupid?

4

IF it works, it's clever. But if this is for other than just testing, then you need to do the test over a long time period and various environments.

5

thats why i asking here. before long run maybe someone comments ,positively or negatively, or share their experiances

6

Sounds fine to me

7

At the sensor itself. Sounds fine.

It sounds as if you are using a 10k pull-down resistor. If using a Nano - or the less appropriate UNO - you should be using a pull-up resistor and the sensor connected between an analog input and ground.

The obvious approach here is to use the internal pullup with pinMode of INPUT_PULLUP. 470k would then read about 950. :+1:

8

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