Audio Cable length for Escape Room Puzzle

Hello Everybody!
First of all I want to thank the community for everything I've learned so far in the forums! Great Help!

English is only my third language, so please, be understanding, I'll do my best to make this post understandable.

I'm new to Arduino, I have some background on web programming, I'm loving it an I definitely want to learn more, I hope you expert guys can help me.

Now to the thing...

I'm designing a puzzle for an Escape Room Facility, the puzzle represents a spaceship command center and the players need to "Hack it". To accomplish the Hacking they need to connect a couple of devices to the command centre through a few cables they need to find hidden in the room.

The command center will have a few of this cables, each one labeled with a different color:
goo.gl/phBlpe

My plan is to cut them in half and connect the female half to the hidden Arduino, and the male half connected to the female part with the cut end hidden so it is not visible, this way it looks like the cables are connecting the control center to something else in the ship.

Th players will need to find the cables around the room (M/M 1 meter/ 3 feet long cables goo.gl/Uzls0D). Once they have the cables they will need to disconnect the female part of the cable mentioned earlier and connect it to the "hacking Machine" using the M/M cables they found in the room.

The hacking machine is noting but a box with a few female jack connectors (each one a different color). All the jacks will be Stereo, so they have two lines. My intention is to jump this to lines with a different resistance in each of the female connectors in the Hacker box, so Arduino will be able to read a different analog signal from each of the resistances.

The idea is that the players need to connect each female cable connected to the Arduino to the right female connector in the box (same color), if they do it right, the Arduino will read the right analog signal, if they do it wrong the resistance will not mach the expected signal and Arduino will know it is wrongly connected.

I have two questions:
Is this kind of cable good for this kind of use? Is it too big a gauge? Is it too large?
Is there a better way to design the circuit?

If the cables fit the game then there is no such thing as too large as far as the electronics go.

Grumpy_Mike:
If the cables fit the game then there is no such thing as too large as far as the electronics go.

Thanks Grumpy_Mike!

I read somewhere that long cables could cause unreliable analog inputs. Maybe I misread it!

It could but that is minimised if the cable is bigger. If you get that problem then the simple fix is a capacitor between the analogue input and ground. A 0.1uF ceramic is a good start point.

Also keeping the resistor values low drives more current and so is less susceptible to interference.

Grumpy_Mike:
It could but that is minimised if the cable is bigger. If you get that problem then the simple fix is a capacitor between the analogue input and ground. A 0.1uF ceramic is a good start point.

Also keeping the resistor values low drives more current and so is less susceptible to interference.

Thanks again Grumpy_Mike!

I should use a voltage divider to get a good reading right?

You should have a resistor from input to 5V and then you can measure he result of differing resistors to ground when you connect it to certain things.

also you can put the resister inside the plug with the cable only mechanicaly connected inside not electrically, as only the female cable actually needs to be "live" unless you want something to happen at the far end. This would also reduce the added resistance of the wires in the cable.

Another idea is if you're using stereo headphone type cable which is normally "two core shielded" is have some wires with only left channel connected, some with only right channel connected and some with both connected. For this to work you need to use the shield as the common outbound voltage and the left and right (normally red and white coloured) wires connected each to one analog pin. Thus you would have two inputs per cable connected to the arduino - 1 for left and one for right so you would then be able to use fewer resister value combinations and so reducing the risk of false positive readings as you would have bigger gaps between values
For example 100ohm, 1kohm, 10kohm x 2 channels gives you 9 possible value combinations per cable.

You will need to do tests to determine the best values.
Also you could raise the complexity by making two or more sets of male cables, one set with only 2 or 3 differant possible resister values for "easy" and say 6 differant resister valies for "hard" with a simple switch on the arduino to select the difficulty level and tell it what set of values to use.

When building it, have the arduino connected to a pc with the readings being sent via serial.print commands to help troubleshoot your code when you connect it all together.