Decoder Box

This is a secret decoder box for a geocache or escape room. There is a 12 position rotary switch. I only use 6 of the pins (the other 6 positions act as an 'off' switch). You could use a 6 position rotary switch. In this case, I would suggest the addition of an off-on switch.

Position 1: Red LED is illuminated. (Switch is pointing to the #4 on the face plate)

Position 2: N/A (off)

Position 3: Yellow LED is illuminated. (Switch is pointing to the #2 on the face plate)

Position 4: N/A (off)

Position 5: Blue LED is illuminated. (Switch is pointing to the #5 on the face plate)

Position 6: N/A (off)

Position 7: Red & Yellow LEDs are illuminated. (Switch is pointing to the #1 on the face plate)

Position 8: N/A (off)

Position 9: Red & Blue LEDs are illuminated. (Switch is pointing to the #6 on the face plate)

Position 10: N/A (off)

Position 11: Yellow & Blue LEDs are illuminted. (Switch is pointing to the #3 on the face plate)

Position 12: N/A (off)

The code used 6 colours, each to correspond to a # on the face plate. 3 primary colours (Red, Yellow, & Blue) and 3 secondary colours (Orange, Purple, & Green).

Example:

You may have a combination lock with the colours Purple, Blue, Orange, & Green. This would indicate that the code is 6-5-1-3. Purple is made up of Blue & Red. When the rotary switch is pointing to the #6 on the face plate, the Red & Blue LEDs are illuminated.

Video:

[Play Video]

Step 1: Gather Your Materials

Hobby Box - 3.17"L x 3.37"W - Digikey #HM1103-ND

12 position rotary switch - Digikey #EG1951-ND

Switch knob - Digikey #450-1736-ND

Red LED - Digikey #L10001-ND

Yellow LED - Digikey #L10007-ND

Blue LED - Digikey #5100H6-ND

9V Battery Holder w/ leads - Digikey #BH9VW-ND

3x resistors - 1000 ohm

6x diodes - 1N4001

9V Battery

Wire

Solder

TOOLS:

Wire stripper

Soldering gun

Drill w/ multiple drill & driver bits

Saw

Sandpaper or file

Ribstone Creek Brewery box

Step 2: Trim Switch Shaft

Because my switch shaft was too long, I cut it down to the required length for my box and knob with a hacksaw. I cleaned up the edges of the plastic shaft with a file.

Step 3: Drill Mounting Holes

Drill holes in the face plate for the switch. This switch has a small indexing stub beside the main shaft. Drill holes for the 3 LEDs. I don't have a picture of it, but the Battery Holder also requires holes.

Step 4: Solder LEDs & Diodes to Switch Pins

The LEDs push into place.

On pin 1: Solder the anode of the Red LED and the cathodes of 2 diodes.

On pin 3: Solder the anode of the Yellow LED and the cathodes of 2 diodes.

On pin 5: Solder the anode of the Blue LED and the cathodes of 2 diodes.

Step 5: Solder Diode Anodes

Okay, in the last step we connected the LED anodes to pins 1, 3, & 5.

We also connected only the cathodes of six diodes to the switch. (two each to pins 1, 3, & 5)

Now we are going to solder the anodes of those six diodes to other pins in order to create the secondary colour combinations.

From the two diodes on pin 1 (with the Red LED), connect one of them to pin 7 and the other to pin 9.

From the two diodes on pin 3 (with the Yellow LED), connect one of them to pin 7 and the other to pin 11.

From the two diodes on pin 5 (with the Blue LED), connect one of them to pin 9 and the other to pin 11.

Step 6: Solder Resistors

The cathode of each LED is solders to a resistor. The other end of the resistors are soldered together to the negative lead of the battery holder.

Step 7: Schematic

Here's my circuit diagram sketch I made for this instructable.