Candle in the Wind (Version 002)

I have updated the candle so that it looks a little bit more like a candle.

Although the assignment was to replicate the essence of a candle, not necessarily remake a candle in the literal sense, I decided to enclose my e-candle in a way that evokes the real deal. Since I’m going for the feeling of lighting and un-lighting a real flame, I figured a true-to-life look would help sell the experience.

When all you have is a hammer…

Last week I took my first DIP into ATTiny waters. Although using the ATTiny adds a tad more complexity into completing a project, it opens up many new possibilities for small enclosures.

Originally I didn’t intend to use the Tiny this week. I had procured a large candle to house the electricals, but like a muppet I drilled too fast into it and broke it in half.

A candle, broken in half.

I panic-raided the junk shelf to see if there was an appropriate container that I could melt the wax into or something, and found a single tealight candle. Not one to shy away from a challenge, I found myself asking: can I fit A into B?

Thus came about my second attempt with the ATTiny85

The Process

The process was simple enough, since I had everything breadboarded up. I first made sure the circuit worked on a Tiny, which it did without much trouble.

I had a blank PCB board that, with some adjustment, fit nicely into the candle’s cavity.

I got pretty tunnel-visioned during the soldering, so the only picture I have of the process is of these markings I made to help me identify the different sides and orientations of the chip…

Fortunately everything went well.

In the end the package just fits within the candle. The microphone sticks out a little but as the project currently stands that is unavoidable. Perhaps the next iteration of this project could involve a NeoPixel ring instead of the jewel, and house all the different sensors on the inside of the ring.

The Outcome


The first week’s assignment for Light and Interactivity was to experiment with different types of LED fades. The technical output was “create an uninterruptible fade. With these constraints I found an adequate box in the junk shelf, glued on some googley-eyes, and created ‘LightBot, the anxious robot’.

Lightbot has a pleasant slow blue breathing when it’s asleep, a healthy green heartbeat when he’s awake, and a panicked ‘HELP ME’ fade when it’s upset. Lightbot gets upset when it’s turned upside down…

I spent a bit of time experimenting with different fades on an Arduino Uno. I settled on a fast sinewave for ‘happy’, a slow sinewave for ‘asleep’ and two quick pulses followed by a pause for ‘panicked’.

At the end of the code for the two pulses, ‘state’ is multiplied by ‘intensity’, creating the two on, two off pattern.

Once I’d found the right fades I used the Uno as a bootloader to load the sketch onto a ATTiny85 so I could fit all the electricals inside the body of LightBot. I followed this guide to set up the tiny.

ATTiny85 with an accelerometer on pin A2, and 3 distinct LEDs on pins 0 – 2