I'm using a Hero board so I hope it's okay to post this here.
I'm trying to use these for leak detection so I'm not concerned about the responses of people saying these sensors don't last long in soil. I'm going to be experimenting with putting them in window sills and on my basement floor by my water heater and the sump pump.
I got one of them hooked up on my bench and have it giving me readings. I'm not to the point where I'm actually using the readings yet I'm just trying to prove the concept of being able to use these.
Since I was getting readings I decided to see what would happen if I connected 2 more sensors so now I'd be using A0, A1, and A2. The other 2 connections are VCC and GND.
As soon as I connected the Arduino I started seeing smoke. I immediately unplugged it. I took a minute to verify all my wiring and make sure nothing was touching that shouldn't be. I quickly tried once more and unplugged again when it still smoked.
Upon close examination I'm seeing a white dot on what looks like D3 or U3 I can't really tell which one.
I unplugged all the wires connected to the board and now when I connect it to the computer it's fine and seems to operate normally.
Any idea what may have happened?
I know the concept of using MOSFET's when driving LED's. Is there a similar need for a project like I'm doing?
Thanks in advance.