Adding RF to a non-RF ITEAD Sonoff

Yes, sure! You can buy a Sonoff RF and you are good to go, I guess. But I didn’t and I was not so sure about the no-named RF receiver so I ended thinking about adding my own.

But first things first. The Sonoff is an ESP8266 based smart switch by ITEAD which comes with a custom firmware that communicates with the manufacturer cloud to provide “smart” capabilities like remote switching or scheduling. The cool thing is that it has a line of pins that expose the VCC, GND, RX and TX pins of the ESP8266 and a buttons attached to GPIO0 so very soon it got hacked and there are a number of firmwares already available. I’m not an early adopter and some work has been done and reported by Peter Scargill, Javier or even in instructables.

The ITead Sonoff Smart WiFi Switch after a small hack to use the Avidsen RF remote to toggle it

The ITead Sonoff Smart WiFi Switch after a small hack to use the Avidsen RF remote to toggle it

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Wordclock with Green Matrix effect

Clocks are top projects for the maker community. There are tons of different ways to show or tell time. Or write time. Wordclocks are a subset of them by its own. You can find other wordclocks at instructables, for instance, or buy one from thinkgeek or from a local jewelry for just 450€. Mmm… well maybe that’s a little bit on the expensive side…

Recently I’ve been doing things with clocks and WS2812 LEDs (a.k.a. NeoPixels). My interest started with Philippe Chrétien’s Fibonacci Clock campaign at Kickstarter. I thought: “Wow! That’s cool AND freaking freak! I want one”. But the $100 and the instructable he himself had done before about building your own made me decide to try it. Anyway, that’s a different story.

That project led to this one. Because suddenly I happened to have 9 spare boards with an atmega328, an RTC, an SDCard slot, some nice buttons and the circuitry to drive a bunch of NeoPixels. I also happened to have a couple of LED matrices (you know, the kind of stuff you have in your bedroom drawer). So first I built a clone of the The Game Frame Pixel Art Project. It was great and my kids loved the pixelart. But I’m not going to talk about that project either.

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PCB milling

it’s been a while (ok, more than a whole year) since my last post. I could say I’ve been busy and it’d be true but I regret myself not writting here for so long… Anyway if you want to know what I’ve been doing just visit my family blog (only in spanish, sorry).


Blue footed boobies (yes, I know). Nothing to do with this blog but part of our family trip.

My idea now is to revisit old projects, the ones I’ve been working on for the last 18 months and even older, and also to write about new projects I’m involved right now. Good bye chronological order.

The months prior to our travel to South America I was working on some collaborative projects related to Barcelona’s network of public fablabs (named Ateneus), and here I am to share with you one of those projects, not only because I found the initiative interesting and the project worth sharing, but because it was cool to see how a 1.8×3 meters CNC mill (that’s 5.9×9.8 feet working area, for you imperialists) will remove the copper from a 2x3cm clad.


Do you see the copper clad? Me neither, but it’s there…

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9600bps clock source

Quick post from an old draft, mainly as documentation.

A 9600Hz oscillator circuit based on a 2.4576MHz crystal and a 74HC590 binary counter. The idea was to reproduce the set up from site with a bar crystal but I had some trouble making it work. The solution came from this document about crystal oscillator circuits that describes different circuits depending on the crystal frequency. Here you have the schema and a picture of the circuit:

9600Hz oscillator circuit

9600Hz oscillator circuit

Prototyping it in a breadboard.

Prototyping it in a breadboard. The DSO Nano is out of focus but shows a 9.60kHz signal.