Esther Rolinson 'Revolve' installation at Curve Theatre, Leicester

So, this is the installation for which I have been working so hard on the modular power LED string. See those glowing internal lights?

Beautiful work, just sad I didn't get to see the finished piece in person. 

LED fidget spinner

It was my recently my son's birthday and although fidget spinner madness is starting to wane now I thought it was worth trying to cram some electronics into one. I found an Instructable that I took as inspiration and put my own spin (!!) on it. I wanted it to be see through as my son likes to see the workings of things (he would have just taken it apart otherwise!), which caused some issues when trying to grind things out as it tended to melt. Anyway I managed to get some really cool tiny switches from Rapid (2.5mm thick!) and ended up with this.

Wifi RFID sender

I have been putting together an RFID reader that can send tag IDs over Wifi to a machine running Max MSP on the same network. I have used an RC522 reader which I have blogged about before, and the recent Adafruit Feather Huzzah board which is based on the ESP8266 chip and includes an onboard Lipo charger so is great for portable IoT projects. For once I managed to find an enclosure of pretty much exactly the right dimensions, it was tight but I crammed it in including switch and indicator LED. The hardware will be used for a project at Three Ways School that aims to give non/pre verbal children a voice, more details to follow...

Arduino / Xbee network

I will be running some workshops on the Creative Computing course at Bath Spa in January with kit supplied by Farnell Element14. I want the students to create a network of nodes that communicate with each other and have some element of generative algorithm to them. I have built a proof of concept as seen in the video, a single node generates an audio and LED output and sends the message to another node, that node displays the incoming message and then generates one of its own to signal another unit. Right now everything is generated pretty randomly and the nodes choose another one to send their message to at random. Things will get more interesting when we link colour and audio frequency and think of more interesting ways to generate our message. Perhaps some nodes will favour talking to others or malcontents will start interrupting the current conversation? I am interested to see what behaviour might emerge when there are 10 of these things going and each has its own 'personality'... 

RFID RC522 + Huzzah ESP8266

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This revisits the RC522 RFID reader that we blogged about here. I wanted to be able to use it with a Wifi connection to ping RFID tag IDs over the ether so I started hooking it up to a Huzzah ESP8266 board I had and after a bit of fiddling it worked! Its only sending over serial right now, but if I can get it going over Wifi, this is an incredibly cheap RFID tag beamer. The new sketch with a description of the pin connections can be found here.

Cloud lamp

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I've been wanting to make a cloud lamp for ages at Three Ways and there are a tonne of tutorials online if you want to follow one of them. I wanted to have a remote control for mine but didn't really want to bother with decoding IR or RF signals whilst trying to do lighting animations. I have used those key fob remote controlled relay modules before, but its massive overkill to control an Arduino pin. I spent a long time looking for a remote module that could control 5V pin logic and sure enough found one that is made by Adafruit, but unfortunately it is on 315MHz which is illegal to use in the UK. Seeing as it is the military channel I didn't want to mess with that really and couldn't find any UK options until I found this amazingly retro thing! 

I found it on the 'Flux Workshop' eBay shop for £5.29 which is great for the time and extra hardware it saved me. I have not tested it extensively yet, but it seems to do what I want it to, is on 433MHz which is UK friendly and is the only option besides rolling my own apparently.

Anyway, we now have a way of selecting between 4 presets remotely so I can hang the cloud out of reach, which is good because it would be shredded in seconds! 

I'm not sure what I am gong to do about dusting yet...

Paper craft electronics birthday card

It is my sons 7th birthday today and it has become a tradition to do a paper craft electronics card for him. These have tended to get a bit more complicated every year so there is a warning there to start simple! This one uses an ATtiny 84 chip programmed via an Arduino to run a seven segment display from a 3V button cell. I used very thin kynar wire and copper tape for the connections to make it count up to and flash his age. Definitely one to do before they reach double figures!! 

It would be great to print the circuit outline onto the card to scale and do some nice design on the computer, my drawing (and writing!) skills are somewhat lacking! 

Softpot

I got one of these 'Softpot' membrane potentiometers recently as a way of telling where a finger is pressing on a strip. I rigged it up like a normal pot and it worked but was pretty noisy, I put a capacitor over a couple of the pins and it seemed to help a lot. Then I read that if you press at the top and bottom you can create a short circuit and it gets hot, so I had to try it... It did indeed get exceptionally hot very quickly and as I don't particularly want people to burn themselves or fry the strip (it's not cheap!) I tried adding some resistors. The more resistance you add the more resolution you lose so I settled on the circuit below which seemed to do what I want it to. Besides that, you can read it in Arduino like a normal pot (check the AnalogInput example), though there is a bit of 'floating' when you have taken your finger off that you have to deal with. 

MF RC522 RFID reader

I came across this exceptionally cheap RFID reader/writer kit which includes a card, a tag and two types of headers all for £3.49 and had to buy one! I have previously used the Innovations ID-12 and 20 which cost around £20 before you add the supporting circuitry or tags, so I wasn't expecting much. The RC522 is NFC working at high frequency (13.56MHz opposed to the ID-12s low frequency 125KHz), with a read range of 10cm (slightly less than ID-12), and the most basic tags costing around 70p (similar to LF tags). 

There is an existing Arduino library for the reader which can be installed with the library manager (search for MFRC522) or manually (see the Arduino website for details on installing libraries). There are a load of great examples included for reading writing and controlling things from Arduino, but I simply wanted to get the RFID tag ID into Max MSP to use it to trigger stuff. I got together a sketch which just booted the ID out of serial which I could then read into Max. The Arduino sketch describes the circuit to use and the Max patch is heavily commented, both resources can be found here

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