Wireless bell

We have a Friedland wireless bell. It’s the one of the Libra+ series.

It’s a great bell (D913), but the battery life on the doorbell (D930) is poor. The push button uses a CR2032 coin battery, which provides 3V, but it only lasts for a month. Changing battery every month is far from ideal and we have missed a few deliveries because of this.

Ideally, I would prefer to connect push button to a mains transformer but this is not an option. There is still a box behind our front door that used to contain an old mechanism with batteries. I decided to move the mechanism of the push button indoors, add bigger capacity AA batteries and add a cheap wired button outside.

The D913 push button is easy to dissasemble. At the bottom right corner of the board, a section with 5 pins is exposed. With a bit of help from a voltmeter, I found the following info about the pins.

To ring the bell, all we need to do is to short pins 2 and 4.


I added the header and moved the board in the modified old enclosure.

The only real cost is the new £2 wired push bell.

I hope these batteries give us at least a year of power before we have to change them! In terms of MAh, I think I’m in the right ballpark!

The D930 chime allows multiple pushbells to be used and it can respond with different sounds. This means that one could potentially use an additional Libra+ pushbell with an arduino or raspberry pi to alert the user when an event has occured. 

Quick note on the differences between the Libra and the Libra+: Libra operates on a different frequency (433MHz) from Libra+ (868MHz) and it uses dip switches to select a channel. Libra+ syncs by setting the chime to “listening mode” and pressing the push button.

Broken IKEA Expedit case fixed

I was given an old IKEA Expedit case, flat packed, that was missing screws and dowels. One of the edges was broken, while the piece was being dismantled.  

I thought I could use it as storage/temp work bench until I had the time to build something more permanent.

Fixing the broken piece was easy. Nothing a bit of glue could not mend. As this was going to stay in my workshop, I didn’t try to make it nice in any way.

Putting it together was also easy. I glued some of the dowels in place and found some IKEA screws that fit it perfectly, so I was up and running with minimal effort.

Reusing furniture makes sense. In general IKEA pieces don’t age well. Before throwing it away it makes sense to consider reusing it in a different room/function. If you have to throw it away, it’s always a good idea to salvage screws and other IKEA parts, for future projects. 


Web server on demmand

import sys, BaseHTTPServer
from SimpleHTTPServer import SimpleHTTPRequestHandler
protocol = "HTTP/1.0"
host = ""
port = 8888
server_address = (host, port)
HandlerClass.protocol_version = protocol
httpd = ServerClass(server_address, HandlerClass)
sa = httpd.socket.getsockname()
print "Serving HTTP on", sa[0], "port", sa[1], "..."

The above example serves all pages/files in the current directory, as long as the host:port combination is accessible.

Great if you want to quickly test javascript or send a document to your iphone!

Meet ESP-8266

And when we thought things couldn’t get smaller… Here is an amazing little board with plenty of i/o, wifi, micro-usb and on board antenna.

Almost same size as an SD card and can be programmed with the Arduino IDE we all know and love.


There is one thing this board needs. A new name. ESP-8266?! Come on!

LadyAda has a better name for it: Huzzah!

Hacking IKEA stuff: From stool to bedside table

I wanted to convert these IKEA stools to bedside tables. The reason was that they match the rest of the bedroom furniture abd there was limited space near the beds, so we could not really  use normal bedside tables. 

INGOLF is a great basic stiol from IKEA  

To add a shelf to it, I just got an extra shelf of KOMOLEMENT  and cut two pieces at the right size, using my table saw.


 I decided to remove the diagonal support pieces, to make it look more like a bedside table and less like a stool.


it was then easy to fit the custom shelf using a couple of plastic fittings:

I used iron-on tape I bought on Ebay to hide the cut sides of the shelf. I got 5cm, to cover both the shelf side and the horizontal support piece. The tape was a but wider than required, so I removed the excess using a chisel. It was the first time I used this simple iton-on tape and I think it worked pretty well.  


And here is the final result. One extra shelf where we need it!