Electric candles

Many flameless candles have a plastic flame on a pivot, lit from below by one LED, with a small coil underneath that nudges the flame so it sways. A PropMesh board can drive both as a single Candle output: the LED flickers like a real flame, the coil keeps the flame swaying, and the candle lights, gusts and goes dark with the show.

Setting it up in the console

Assign the LED’s pin to Candle (flicker LED + flame coil). Two options sit beside it:

coil: the pin that drives the coil.
LED on = LOW: tick this if the LED lights when its pin is pulled low. Most candle boards sink the LED through the pin, so this is usually on.

The CANDLE settings shape the flame. The ? next to the label shows this same summary in the console.

Setting	What it changes
drama	how strong every effect is: 0 is a calm, steady flame, 1 is a real candle, 1.5 is one in a draft. It also sets how hard the coil pumps in a gust.
floor	the dimmest the LED ever gets. 3 % lets a sputter look like a near-blowout; 30 % keeps the candle looking steady.
gust every	the average time between gusts: quick dips in the light with a big swing of the flame
sputter every	the average time between near-blowouts, where the flame stutters and flares back. 0 turns them off.
swing	how often the coil kicks. Match it to the flame’s own swing with Find the swing….
kick	how long each coil pulse lasts. Longer kicks swing harder and use more battery.
swing the flame	untick to keep the flame still while the LED flickers
draft	candles in the same draft, A to H, gust and sputter together, as if one breath of wind crossed them all: the same moment and the same strength, while each flame dips in its own rhythm and keeps its own shimmer and sway. They can be on different boards. Alone means its own random timing.

Gusts and sputters come at random intervals around those averages, so the flicker never falls into a rhythm.

The coil follows the flicker. At rest it keeps the flame swinging with kicks whose strength drifts up and down, so the sway varies but never dies away. Just before a gust it starts pumping harder, up to about 1.7 times the kick at full drama, and keeps going for a second after, so the flame swings most as the light dips.

Several candles on a table or along a path look best in one draft: the gust reaches them all within a third of a second, each answers in its own way, then they go back to flickering on their own. This works from the mesh clock, so it needs no extra wiring and keeps working even when the candles can’t hear each other directly.

Finding the swing

Each candle’s flame piece has its own natural swing, like a pendulum, and the coil moves it furthest when its kicks land at that rate. Press Find the swing… in the candle’s TEST column. The board then kicks the coil at one rate with no gusts, and holds the LED steady instead of flickering, so all you have to judge is how far the flame piece swings. Use the brightness slider to make the light dimmer or brighter while you watch.

Sweep steps the rate up by 0.10 Hz every 2.5 seconds, from 0.5 Hz to 6 Hz and around again. Watch the flame and note the rate where it swings widest. The sweet spot is usually between 2 and 4 Hz.
− and + nudge the rate by 0.05 Hz. Pause the sweep near the widest swing and nudge until the motion peaks.
Steady / Bursts switches between kicking every cycle and kicking in sets with a rest between. If steady kicks don’t get the flame going, try bursts: the rests let a set catch the flame at a different point in its swing.
Then the kick. With the rate found, use the KICK row’s − to shorten each pulse by 2 ms at a time. When the swing visibly shrinks, go back up one step. The lightest kick that still swings the flame fully is the one that keeps the coil cool and the battery lasting.
Use puts the rate and the kick into the candle’s settings. Then press Save to node.
Stop ends the kicks. The board also stops on its own after two minutes, because the coil warms under steady kicking.

In the show

The candle’s TEST column has a brightness slider, Light and Out, and Gust and Sputter buttons to try the effects on demand.

In a sequence, a candle is a track like an LED dimmer: its value is the brightness of the flicker, 0 puts it out, and it can fade. A candle that fades up at dusk as part of an ambient loop, and gusts when a scare goes off nearby, is a few steps.

To keep it lit all evening, make it an ambient loop: a new sequence with one step, the candle at full brightness, with Ambient loop turned on and every set to 600 s. The candle then lights whenever the show is Ambient or Armed, including a few seconds after the board restarts, and goes out with Off, the schedule or STOP ALL. A board restarts with every output off, so without a loop a candle stays dark until something turns it on.

If the candle runs on its own cell, tick On battery for the board. Left on mains power the board never sleeps and the radio runs all day, which empties a small cell in about a day. On battery it sleeps outside the show and the flicker and the coil work as before during it. See Battery boards.