Hello!
I am testing out a concept for a touring theatre show and need some help with the electronics for UV shoes, please. The shoes are worn by the children participants.
I am looking to build false soles onto shoes to house a battery, charging port, sensor and UV LEDs which are (ideally) off when the foot is lifted. When the foot is down the lights are on and leave a lingering glow in the floor (we have a UV sensitive floor).
The theatre company works only with kids, so the shoe area to work with is fairly small.They have 5V battery charging system (from a previous show) so the shoes’ batteries only need to last 4 hours between charging.
My crude tests indicate that the flat style UV LEDs, like the end of a UV torch or the panels used for curing resin give great coverage for the shape I need.
Jane has provided some thoughts on my parts list and has suggested I ask the forum for help.
I am not an electronics person, but can solder some basics and can definately make the shoe.
Your advice is appreciated.
Here is my list:
FSR (pressure pad) (or a small mechanical micro switch was suggested by Jane)
Comparator (adjustable threshold)
Battery (Jane has suggested I look at a a single‑cell LiPo paired with a boost regulator)
I understand the batteries pose a risk and the wiring needs strain relief.
I need to have the test concept done quickly, and can make further refinements from there.
Any help defining a test parts list would be very much appreciated!
To get a better idea of the parts list, could you please send through some more info?
A link to the UV LEDs you intend to use (to estimate power draw) If you dont have any in mind just yet, we do stock these: LED - Ultraviolet | Buy in Australia | COM-08662 | Sparkfun | Core Electronics
Will the shoes be on 100% of the 4 hours? How long would you expect them to be on for?
Could they pulse on once the shoe hits the ground, stay lit for a certain amount of time, then turn off?
Other maybe difficult parts of the project could be making sure the shoes are durable enough to last practice and the show.
Thanks for the feedback Liam, it is definitely an interesting make!
The UV LEDS - I have been given strip by the theatre company and can note the details tomorrow. I was leaning away from it as it may be troublesome to manoeuvre it into the shape I need (only part of the footprint). Thanks for suggesting these LEDS. For a striking image on the floor it would be great to concentrate them. Based on the spacing on UV torches I can imagine I could use 15 or more per shoe.
Usage - Participants rotate through the activities and I think it is 20m max per use, totalling 4 hours a day. But then many shows (eventually, I just need to prove a concept asap).
Pulsing - Switching off is ideal for two reasons. 1. There is some magic in the kids not being able to see any light when they pick up their foot (I expect someone will want to look at their shoe to see how it works) and 2. The floor surface will make the best impression of the intended shape when the light is close to the surface.
Oh, on second reading, maybe you are saying they could come on for a determined pulse length of time? Yes, that would work. So I would need a microcontroller in each shoe? Ok!
Robustness - I think for the actual show I would expect to make many multiple pairs and accept some loss. I am a pretty good maker so will embed securely into a false sole.
You can use a mechanical micro-switch (heel or toe) to directly switch the LEDs on/off (low parts count). Use a protected single-cell LiPo (with JST connector), and either:
a combined boost+charger board (Adafruit PowerBoost 500C or similar) so you have a single board for boosting to 5V and safe charging; OR
a separate TP4056 charger module + a boost converter (if you already have a 5V charging ecosystem).
