Transfering 6 switched states across 2 (or 3) connections...


Joined Jun 2, 2008
Just throwing this out there.

I presume the switches are just lighting LEDs and nothing else?

Use the switches to short out resistors on a resistor chain and monitor the voltage at the other end with window comparators to determine which switches have been operated based on the returned voltage and light the corresponding LEDs.

After a little thought it's next to impossible with one channel looking at six switches. You have three wires available so a 2 channel solution is available which will take some thinking about. Use a four way jack plug and you can use one wire to monitor 2 switches which is feasible.

This way avoids the use of programming code but will require a little thinking about and a few op amps! ;)


Joined Apr 5, 2008

You state you have 6 switches.
Is only one switch used at a time or can there be a combination of switches active?



Joined Apr 5, 2008

Then there are two possibilities.
1) serial communication as others also mentioned.
2) DAC / ADC conversion, wich might be more sensitive to failures, depending on the voltage range used.



Joined Oct 29, 2013
Just to throw this against the wall... What if the place you put this thing down had a specific shape to lock the piece in place, and had 6 circles of decreasing diameter inside each other, and a dot in the middle. Then the bottom of your mobile piece can have 7 pins, each at the proper distance from center to touch one of the circles. Now it doesn't matter which way the item is set down, as long as it's in the correct location.

Also wireless is cheaper and easier than ever. You would only need 2 contacts for power, and the data can go wirelessly. Though that's going to require more thinking.

Thread Starter

Jonathan David Bond

Joined Nov 10, 2015
I've considered concentric contacts, but worry about getting a good connection due to dust etc... The pieces would need to be weighted or magnetic to be secure. Also they have the potential to make the base of the piece bigger than I would like.

I've discounted wireless, partly because I may still need to decode inside the piece and the 2 options I can think of both have drawbacks.

Rf - there are 16 locations and 4 pieces, signals could get crossed.

Optical - needs direct line of sight, which needs the piece to always be placed the right way. Also suffers from dust and other contaminations.

But I like your thinking.