Background
When I created my first friendship lamp version, I loved how interactive it was and the connection it brought me to my best friend during the Covid-19 lockdown. One thing I noticed, though, in mine and other commercial versions, was the lack of variation in features and design. Every friendship lamp I’ve found follows the same design premise- a multicolor LED that can be controlled by the other partner lamp. I thought it might be cool to design a friendship lamp with a new, more aesthetic style.
Inspiration
I’ve always liked the look of wooden/industrial looking “Edison bulb” style lamps. There are many commercial regular lamp options in these styles, as well as many tutorials online on the creation of these lamps from scratch. I thought it would be cool to design the friendship lamp to follow the look of these, with touch controls that cause the partnered lamp to light up and pulse in relation to the interaction with the first lamp and vise versa. Some of the design inspirations are below.
Wood Enclosure Design
I wanted to follow the “wood box” style of the inspiration lamps, and I couldn’t really find any commercial boxes to buy that had the style I wanted, so I decided it was time to learn how to do some woodworking.
After getting a plank of pine wood, I cut it to squares of equal dimensions and drilled out the center of a portion of them to make room for the electronics. A smaller hole was drilled in one square for each lamp for the lamp socket to go through. These pieces were laminated together with wood glue, and then sanded for hours to get a good finish.
As I found stain to work terribly on pine wood, I decided on just conditioning and varnishing the boxes, which came out quite nice.
Electronics Design
To act as a touch sensor, I soldered together a brass ring that went around the wooden enclosure upper edge and connected to a touch sensor. 5V for the electronics was gotten through a disassembled 5V USB phone charger to prevent the need for custom AC regulator circuitry.
Since I wanted to be able to control the brightness of the AC bulb, not just on and off, I used a AC dimmer circuit with zero cross detection and a triac. I first prototyped this out using off the shelf components, and then tried to shrink the off the shelf components into a small enough form-factor to fit in the housing. Although I barely got it to fit, I wasn’t comfortable with such a cramped and messy electrical system dealing with mains power. Because of that I went to create a custom WiFi-connected AC dimmer PCB for this project.
To reduce the form factor of the design, I made a custom PCB of the same electronics circuit. I wanted to keep this project simple so I used an SMD ESP32 module with antenna instead of making that embedded RF circuitry from scratch and having to deal with FCC regulatory requirements if I ever sold these. The PCB is below.
Software
Just like my previous friendship lam version, communication between the two lamps occurred over the Adafruit IO Free MQTT Network which made my job much easier. The software was set up so when one lamp was touched, the other would fade on and then slowly fade back down over the course of 20 minutes. If the first lamp was touched again during this period the second lamp would start pulsing to show the user that the other lamp was being actively touched. This worked in both directions.
Result
I only ended up having enough resources at the time to make one of the lamp’s electronics, but I still got good data from one and really loved how it looked and the features it had. I feel with sone more improvement it definitely has potential, and I would love to revisit this project in the future to get both lamps fully working and connected. Here is a video of the lamp doing a test pulsating pattern.