A small mistake that may be fatal to the sensor

Support Sensors
1

Hello!

I am using a Nodemcu 32s esp32, when using a QTR-MD04RC with it on pins 12, 14, 27, 26 (all in order) it worked at the start of this day. However, as I’ve tested it with other pins then went back to the first 4, it stopped working (as in it showed values 2500).

I have an idea the sensor may have beoke down since i accidentally connected gnd to 5v and vice versa.

However i have doubts since it was like this at the beginning when i first unpacked it and used it (aka only showed 2500 values).

My question is if it can break if you connect the gnd and 5v of the sensor to the opposite of it. Also, what can i do to fix it if it actually isn’t broken?

(Note: I’ve used the rawvaluesexample mostly to test the values and it still appears to show 2500)

2

That is just about always, and instantly, fatal.

We have all made mistakes like that, and learned to be more cautious. A good rule of thumb is to never change wiring while the power is turned on.

1 Like
3

Thank you for your response!

Dammit now i gotta buy a new one though HAHAHHAHA

4

Hi, mcduffie.

These sensors do not have reverse voltage protection, so connecting power backwards will likely destroy them. However, if you didn’t see any smoke come out or other visible physical damage, you could hang on to it until you have a replacement to verify that your setup is working correctly. At least they’re on sale right now!

- Ben