You just made a funky neon sign flash in my living room.
How? I have just completed my latest project which is a neon lamp which lights up every time someone visits my website. It’s controlled by a little relay board I built out on an Adafruit permaproto board and connected to a Raspberry Pi. The Raspberry Pi is running a simple python script which generates an event every time someone loads this page. I’ve made the part which integrates with the website open for anyone to use so you can build this out for yourself – have fun!
Building the Relay Board
The relay board connects to the Raspberry Pi General Purpose I/O (GPIO) pins via a ribbon cable. Adafruit sells a Pi Cobbler which makes it easy to break out the GPIO pins on a breadboard for prototyping. Once you’re happy that the prototype is working, transferring a breadboard layout to the permaproto board is quite simple (the soldering is easy and you just copy what you had on the breadboard).
Here is the circuit diagram for the relay board – we drive the relay coil from the 5V supply which is switched on and off using a transistor controlled by one of the digital out pins (I used pin 18). The diode prevents reverse voltage as the relay switches off from damaging the Pi.
You can see step-by-step instructions on how to assemble the relay board on this spark.
Connecting the lamp
You can use any lamp or electronic device powered with a low direct current (anything which plugs in to a USB port or runs on batteries is ideal). DO NOT attempt to use a mains powered lamp. Even if your relays is rated for 110V, the prototyping board has exposed connections and mains electricity can kill.
Simply cut one side of the power cable and attach to the switched part of the relay (I used screw terminals so I can connect and disconnect as I please).
For more detail: Raspberry Pi Website Hit Tracker