Instructables

Electric Imp to control 8 electrical lights using internet

Featured
Picture of Electric Imp to control 8 electrical lights using internet
This project uses the new (and super cool) Electric Imp.  You can remote control 120VAC electrical devices over WiFi, via the internet Imp Cloud.  The Imp sends a serial string of bits to a "Serial to Parallel" digital output chip (made by Texas Instruments).

Basically, the 'gist' of the project:  You send the Imp a value (0-255 decimal or FF Hex) and it sends that stream of bits out of the UART serial port (pins 1 and 2).  The TI chip can only receive bits, so Imp pin 2 (RX) is not used.  The TI chip converts that serial input into 8 digital outputs.  Electronically, it can turn ON or OFF any of the Solid State Relays.

The TI chip is addressable, 0-7 using 3 bits.  That means you could technically have up to 8 of them in a line to drive 64 digital outputs.  The scope of this Instructable does not include extending outputs beyond one chip.  Also, the TI chip only receives serial bits and does not send any data back.  For bi-directional UART, you would need to use a different method.

I selected this TI chip because it doesn't need a clock.  It synchronizes automatically based on the timing of the first start bit.  This makes the circuit super simple and easy for anyone to construct.  No oscilloscope or logic analyzers needed.

This Instructable does not describe how to commission an Imp.  You'll need to view the Electric Imp website (www.electricimp.com) to learn how to register, login, commission, and create an account for your imp.

If this is your first encounter with the Imp ... please see this Instructable first:
http://www.instructables.com/id/Getting-Started-with-Electric-Imp/

The main parts:
Everything except the solid state relays can be built for under $100USD.

- Plastic box that can withstand outdoor weather. 
Use plastic because of the imp inside ... WiFi reception.
I used an old cheap plastic toolbox. Waterproof, w/carry handle.

- Electric Imp
Sparkfun Cat No. WRL-11395  (approx $30USD)

- April Electric Imp breakout board
Sparkfun Cat No. BOB-11400  (approx $13USD)

- TI (Texas Instruments) Serial to Parallel chip: 
Mouser Electronics Cat No. 595-SN74LV8153N (approx $2USD)

- Blank project board for soldering parts onto
Mouser Electronics Cat No.  782-T030081 (approx $5.50USD)

- 7805 5VDC Voltage Regulator
Mouser Electronics Cat No. 595-UA7805CKCT (less than $1USD)

- Solid State Relays (SSR)
3-32VDC input ... 120-240VAC output
These are expensive, but you can find used ones on Ebay

- Misc LED, resistors and capacitors, solder, hookup wire
 
Remove these adsRemove these ads by Signing Up
andstdout6 months ago
Hi, nice instructable!
Fyi, there is a cool software for iOS and Android where you can build a custom UI which let you customize buttons/ switches/ sliders etc. for http APIs. It's called NetIO: http://netio.davideickhoff.de
I also use this software to control wireless outlets and a ElectricImp Moodlamp.

mlseim (author)  andstdout6 months ago
There is also a free app that is made just for the Imp:
https://itunes.apple.com/us/app/little-devil-controller-for/id675068320?ls=1&mt=8

I'm really into online apps and server-side scripting. PHP and Perl.
But it's nice to get a list of more options. The more, the better.


theshades6 months ago
You could in theory connect the IT chip to the Hill320 (Computerchristmas.com) and have 320 outputs for each eight bits of output from the ITchip that is 8x320=2560 outputs! Then you need a plugin for Vixen 2.0.
mlseim (author)  theshades6 months ago
The limitations to the TI chip is speed. 24Kbps is the limit. So with the imp UART12, I have the baud rate set at the standard 19200. I will only be using 8 different displays in my front yard ... and even with that, I have to do a lot of work. Extension cords, wiring strings, etc.

As of yet, there is no 'project page' on the actual Imp website. That's why I am using Instructables. I'm hoping that anyone viewing the various Imp projects here will spark other ideas. Thanks for suggesting other uses. That's what make it so fun.
audreyobscura6 months ago
Awesome! Update this come december, I would love to see it in action.
mlseim (author)  audreyobscura6 months ago
I will try to get a demo video in place before the end of Oct.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!