Introduction: Simple Marker Conductive Interface
Very simple way to make a marker interface for MakeyMakey or other micro conductive input.
Sometimes old input ways are good, both for training and for using pre learned haptic response. In an attempt to see how to best make a marker based way to input to a computer. Successfully did a very quick prototype.
Step 1: Parts List
- Water based marker (or a totally dry alcohol based one)
- Rubbing Alcohol
- Water with a little salt.
- Electrical tape
- Makey Makey, or any other micro current switching interface.
Step 2: Assembly
I was ok with some ink for this prototype, but for my next one I flushed out the pigment and charged with a little saltwater
The simplest way to do it is to push a thumbtack through the sidewall of the marker into the cartridge, Connect the wire to the thumbtack, you could tape over it to keep the wire attached and avoid any possible leakage (very tight fit on mine so was not needed)
Then on another surface run some conductive pads I used copper foil tape, but tinfoil, or even heavy pencil lead lines or wires or entire metal surfaces would work, depending on if you wanted one target or many..
To make a invisible marker, or are using a dried out alcohol marker, pull out the end "cork" plug on the end of the marker furthest from the tip, pliers can be of help with this. (might want to use gloves, may still dye you), remove the cartridge, and the tip of the marker (pliers will help with this too, just pull the tip out.
Place both tip and cartridge into a container with about a cup of rubbing alcohol. and shake, and after an hour or two pour off alcohol (careful not to loose cartridge and tip, and soak with another cup of fresh alcohol. for another few hours, shaking every once in a while. after two soakings. the tip and the cartridge should be a lot less color filled. If this is not the case go for a 3rd soak.
Once they are pretty white, remove them and wash them with flowing water and let that soak overnight. remove from the water and let dry.
Also rinse out the inside of the marker
now re-assemble the marker. put the now drained cartridge in and push the tip back in,
over a sink, add about a tablespoon of saltwater in the "cork" end of the marker. and test it on some white paper, you should see just a wet line where the marker goes. if its not wet add more saltwater until you get a good line but not dripping.
Re install the plug/cork
Now you can use the above mentioned Thumbtack and wire, to wire up the marker. Was fun to see how far away from the conductive pad i could draw a saltwater line and cross it again to switch, (usually less than a few inches when it was extra wet, when the marker was getting a little more dry it only conducted for 1/8th inch. )