Simulated minefield using pressure sensors

Projects General Guidance
1

Hi - I am creating an escape room for my daughter's after-prom party. I am looking to create a simulated minefield that the kids have to traverse. I bought some velostat and wires and have seen a number of basic videos online but am stuck wondering how I can connect, say, a dozen of these to an arduino such that stepping on any one of them will set off an alarm. I am new to this, so any pointers to code, schematics, etc. would be very helpful.

Oh, yeah - after prom is this Saturday (4/28) :wink: - hey, I had my hands full making the laser tripwire!

Thanks,

Pete

2

Which exact sensors did you buy? Data sheet?

3

Here's some good ideas
https://cdn-shop.adafruit.com/datasheets/HandcraftingSensors.pdf

4

Do you care which one gets stepped on? Or just when any of them gets stepped on, the same alarm sounds?

5

DrDiettrich: I am making the sensors myself using velostat and wire and connecting them to the Arduino.

Blh64: Thanks - it seems like creating the sensors isn't too difficult (?) - just exposing two wires connected to the velostat that completes the circuit when pressure is applied. I guess I'll find out if that is a foolish assertion tonight or tomorrow.

INTP: I want to hook them all up to the same Arduino such that if any of them gets stepped on, the alarm sounds.

Thanks for the thoughts!

Pete

6

"I want to hook them all up to the same Arduino such that if any of them gets stepped on, the alarm sounds."

Thats much easier approach IMHO...

7

You can just wire all the switch pads in parallel with each other , then connect to a digital
Input with say and external 10k resistor

8

And here's where I embarrass myself by asking how to actually do that "parallel wiring w/ 10k resistor" config with Arduino - connect them up to a breadboard? (I'm really new to this stuff.)

Also, practically speaking, that means much more wire on the floor... is wiring in series that much more difficult? If I create a 5 x 8 grid and connect each pressure sensor (two wires attached to aluminum foil separated by velostat) along the path using the wires, will that work? What issues will I have?

Thanks again for all the help!

Pete

9

How do your sensors react to the intended pressure? How much does their resistance change?

Do the sensors act like switches, so that digitalRead() can be used, or is analogRead() required?

10

FWIW...

PeteLind45:
...two wires attached to aluminum foil separated by velostat...

is not an on/off switch. It's a variable resistor whose resistance varies with pressure.

To make a momentary contact switch, see the "button" instructions in the PDF in post #2 (BTW, it doesn't involve Velostat).

That's not to say that Velostat couldn't be used as proposed, but if you go that route, you would have to consider the sensor resistances, how much one changes with pressure, determine the other voltage divider resistor value, and what analogRead() level to trigger on.