{"id":537,"date":"2017-05-24T18:02:03","date_gmt":"2017-05-24T18:02:03","guid":{"rendered":"https:\/\/hughqelliott.com\/blog\/?p=537"},"modified":"2017-05-25T14:31:02","modified_gmt":"2017-05-25T14:31:02","slug":"disco-stairs","status":"publish","type":"post","link":"https:\/\/hughqelliott.com\/blog\/disco-stairs\/","title":{"rendered":"Disco Stairs"},"content":{"rendered":"

As part of my \u201cgit \u2018er done\u201d mindset of the past month, I decided to tackle a project that\u2019s been on my mind for a while.<\/p>\n

Our stairs have been painted black. The primary reasoning is they\u2019re old stairs and not in great shape and black is a good cover. However, at night, they’re hard to see. Quelle surprise. (that\u2019s french for \u201cduh\u201d)<\/p>\n

A number of member of my family suffer from Retinitis Pigmentosa<\/a>. It often causes something called Night Blindness. For the time being, I don\u2019t have it. However, my mother does. She walks around in the evening with a bright LED flashlight and I know she struggles on our stairs. I gave thought to cutting a channel into each step and laying down a strip of phosphorescent resin or something white but I wasn\u2019t confident in that approach and worried about messing with the integrity of my stairs.<\/p>\n

So out comes an\u00a0old LED strip I had in a bin. This is a standard RGB LED strip, non-addressable. Non-addressable means I can only light all the LEDs\u00a0the same colour. I can\u2019t light individual LEDs. So this strip has been sitting in a bin for a few years being useless.<\/p>\n

Until now, that is.<\/p>\n

My idea was to use a light sensor that could determine when it’s too dark for someone with moderate vision issues to see out stairs and to activate an LED strip, running under the railing pointed at the stairs, to light up. Thus illuminating the stairs.<\/p>\n

Light sensor (photocell). It’s important to note that most sensors are essentially providing a value of resistance from 0 to 1023. The photocell is no different. I happened to have\u00a0a Sparkfun\u00a0ProtoSnap<\/a> (no longer available) from attending the first EyeO festival. At the time, I didn’t know what to do with it, but from time to time lately, I\u2019ll snap off a part and use it.<\/p>\n

SparkFun ProtoSnap<\/figcaption><\/figure>\n

Using a light sensor generally involves piping voltage through it and reading the analog value from the resistor. The brighter it is, the higher the value. If you\u2019re looking for a simple tutorial, look no further<\/a>.<\/p>\n

Also the LED strip is a 12V SMD 5050<\/a>. That link isn\u2019t the actual strip but it\u2019s similar.\u00a0Here’s a handy wiring guide for connecting the strip to your Arduino through some\u00a0MOSFETS<\/a>. Again, take a gander at the tutorial<\/a> for hooking the strip up and playing a bit with it.<\/p>\n

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So I took both those tutorials and combined them.<\/p>\n

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A post shared by Hugh Elliott (@hughqelliott)<\/a><\/p>\n<\/div>\n<\/blockquote>\n