The more you know… A Material Safety Data Sheet(MSDS) outlines what you need to know about working with something, especially hazardous things. Make these interactive light up data sheets as posters to highlight important facts from the applicable MSDS. Remember to post in a place visible and accessible by all.
Step 1: Get on Board...
I created some artwork in GIMP. You can copy the images attached, use them as a starting point or make your own.
The print images are then glued to a piece of box cardboard to act as a solid base for your signage. I used a glue stick since using a lot of liquid glue would warp the paper. Spray adhesive works best but it has its own MSDS that you should read up on.
You could use anything solid for your base layer: plywood, hardboard, plastic, etc. I have a lot of cardboard laying around to recycle so...oh, don't forget to peel off all the tape and glossy stickers that glue doesn't like to stick to...
Trim around the edges to make everything look neat and professional.
Step 2: 'lectronics and Bright Lights...
I used an Adafruit Circuit Playground Express board but any microcontroller will do. It is capable of being programmed in Circuit Python so I can use it's capacitive touch and sound features.
A short strip of 2 Neopixels is used for the cat eyes. The Neopixels on the board will also be lit up.
I like to solder the + and GND wires on the back of the Neopixel strip at the next full pads down from the cut end. It seems to give a little more support for the fragile end.
I soldered a few extension wires from the capacitive touch pads on the board. They will connect to the wire sensor segments on the cat silhouette image.
Use a thick wire for the touch sensors. This is 12AWG for house wiring. Shape the wire with pliers. Use an awl to punch holes in the cardboard to embed the wire touch sensor segments.
Secure all the loose wire segments in the holes with hot glue or by taping on the back of the cardboard.
Circuit Python code for Cat sign:
Circuit Python code for Dragon sign:
You will have to get your own sound bites to use. They need to be relatively short or .wav files of a small size so that they can fit in the limited memory of the board. I reused the "angry cat" sound I had for the dragon fire since it was the only thing that fit after I cleared up some room by deleting unused library files.
When you get everything running, you may have to adjust the placement of all the wires. Think of the capacitive touch wires as antennas. If they are close to each other, they may impose their signal on the other and cause interference. That translates into someone pushing the doorbell button repeatedly. Try to separate the wires as much as you can and don't have them cross over each other or overlap. I have all the wires pass through one hole in the cardboard from the board and then they radiate out. That initial bunching up should be compensated for when the program runs to establish the base capacitance. The wire that carries the active signals for the Neopixels may affect your sensors only when the Neopixels are lit so take note then and adjust if necessary.
I am just learning to use Circuit Python so I tried to port over the arduino Fire sketch to Circuit Python. The flame effect still needs tweaking. Driving Neopixels in complex animations seem to run slower in an interpreted language like Circuit Python so you have to optimize code and speed up things to compensate.
Step 3: There Be Dragons...
The Dragon Safety sign is constructed in the same manner as the first Cat Safety sign.
Instead of the strip of 2 Neopixels for the eyes, it is a strip of 10 Neopixels. The extra Neopixels make up the length of the flame from the dragon's mouth.
The Neopixel strip is diffused with a strip of white felt and fiberfill batting(plushie stuffing).
Make several interactive signs on whatever topic is needed. Doggo? Werewolf?