Grab a set of jumper cables. Remove the connectors using wire cutters. Peel, strip and tin the ends of each wire. Tin the pins on the TFT display and solder the wires to them. Write the colors to each pin for reference.
Follow the wiring diagram and tin the pins on the Teensy. Solder the wires from the display to the Teensy using the wiring diagram and your color reference notes.
Tin wires to 3.3V and GND pins on the Teensy board. Solder the positive wire from the UV LED to 3.3V and the negative wire to GND on the Teensy.
Secure the Teensy to a pair of helping third hands. Solder the wires from the pushbutton to #0 (wink left) and a ground pin on the Teensy.
To remove light leaking from the inside of the enclosure, paint the LED black using black acrylic paint using a tooth pick.
Use a piece of black electrical tape to cover the bottom of the TFT display. This will help block any light leaking from side the enclosure.
To mount the Teensy and Lipo backpack PCB’s to the panel, we can use tack. Using tack allow you to shift the components around for optimal placement. You can optionally use epoxy or E6000 adhesives to permanently secure the boards to the panel.
Install Display to Panel
Fit the wires from the TFT display in between the bottom left walls (Peel apart the wires if needed). Lay the display over the two pushbuttons with the pins facing towards the top of the panel.
Place the Teensy PCB below the display, underneath the bottom wall. Press it down to secure the tack to the panel.
Insert the slide switch through the hole near the bottom of the face piece (chin). The tolerances should be pretty tight to hold the switch in place, but you can optionally apply adhesives to permanently secure it.
Mount Battery to Panel
Add a piece of tack to the lithium polymer battery. Place it behind the slide switch and press it down to secure it onto the panel.
Stick the Lipo Backpack below the Teensy board. Press it down to secure it to the panel.
With the wings and cabochon installed, carefully lay the face part over the panel. Line up the lip of the panel with the inside of the face part and press them together - it should snap into place.
While holding the parts together, insert #4-40 3/8 size flat Phillips machine screws into the mounting holes on the back of the panel. Tightly hold the two parts together while fastening the screws all the way through until they’re flush with the surface.
If everything fits nicely, flip the switch to power on the circuit. Slowly push the cabochon inward to actuate the pushbuttons. If everything is neatly in place, the eye should wink!
If the screen turns white when pressing the eye, some of the wires are probably shorting out. Take it apart and diagnose the wiring. Ensure the wires are neatly nestled behind the display.
Now its time to install the doorbell. If you haven’t already, you should poke around your existing doorbell and see how it’s being mounted. If it’s using the same mounting plate like in this project, congratulations! You’ve won the maker lottery.
Most doorbells probably aren’t standardized, therefore they’re all going to have different mounting holes.
Once you’ve figured out how to mount the plate, it’s relatively easy to stick the enclosure to it - I used double-sided foam tape. The mounting plate has a large opening in the center to allow the two pushbuttons to fit into. The mounting plate itself is secured to a metal bracket thats fixed to the wall using two screws.
My original doorbell was a slightly larger, so you can see how the non-painted areas show through. There's only two wires that need to connect to the second pushbutton. Since the pushbutton doesn't have specific polarities, it didn't matter which lead is positive or negative. Just be careful that those wire DO NOT touch the wires from the pushbutton that triggers the eye wink. NEVER connect the doorbell wires to the same pushbutton - that would totally cook the Teensy board.