97. Bearing Witness

“Bearing Witness” 10: Done!

https://youtu.be/vnT8qnlGeMQ Here it is! I’m very pleased with the result. It’s hard to tell on a video because the candles are brighter than the dark painting so they over-expose the camera, but I think I’ve done a good job on simulating a flame. As time goes on I’ll experiment with assorted ideas for improving the…… Continue reading “Bearing Witness” 10: Done!

97. Bearing Witness

“Bearing Witness” 9: Software

Candle flicker I wanted to achieve a candle effect. So it lit some candles and stared at them for a while. I mean I did some research… Three things about candle flames: Flickering = fading rapidly and non-linearly between brightness levels Flickers usually loosely follow a pattern, around an average brightness No two flickers are identical…… Continue reading “Bearing Witness” 9: Software

97. Bearing Witness

“Bearing Witness” 8: Assembling the electronics

So, I have 1.2 metres of 2.5 cm right-angled aluminium on which to attach all the electronics. Step one: the candles: I bought a batch of 2.5mm nuts and bolts to attach the LEDs. There’s a washer behind the nut to spread the load where it meets the LED base, and a shake-proof washer by the head…… Continue reading “Bearing Witness” 8: Assembling the electronics

97. Bearing Witness

“Bearing Witness” 7: Assembling the frame

The original frame was of traditional construction. It consisted of four pieces of wood for the front, joined at 45 degree angles, and four pieces of wood for the edge, screwed to each other and to the front. What I needed to do was remove one of the edge pieces – the one at the bottom…… Continue reading “Bearing Witness” 7: Assembling the frame

97. Bearing Witness

“Bearing Witness” 6: Ultrasonics

Next, to get the ultrasonic range-finder working. The idea is to make the artwork interactive: the candles will glow until someone walks up to it, at which point it will begin a new sequence of bright flash / darkness / slow candle lighting. I bought this ultrasonic sensor on eBay for £1.63. It should allow the measurement…… Continue reading “Bearing Witness” 6: Ultrasonics

97. Bearing Witness

“Bearing Witness” 5: Electronics

The Arduino For the previous project I used an Arduino Uno to control the LEDs. It worked fine, but it’s too large to fit inside the frame of this artwork. However, a little searching on the internet came up with the Arduino micro. It has all the same functionality as the Arduino Uno (with a few…… Continue reading “Bearing Witness” 5: Electronics

97. Bearing Witness

“Bearing Witness” 4: Temperature check

As described in the previous post, the heatsink for the Flash is only designed to keep the temperature at a safe level for a few minutes. Since the LED will only be lit for a few seconds every few minutes that’s all that’s needed. The problem is that if a problem occurs with the Arduino, such…… Continue reading “Bearing Witness” 4: Temperature check