Monday, 21 January 2013
I started looking at the classic fonts used in 1960s and 1970s science fiction and identified Eurostile and Futura as the fonts I remember best from films like '2001,' 'Silent Running' and TV series like 'U.F.O.'
I got to thinking how cool it would be to have indicators using these fonts and how to go about making them. A bit of experimenting and I found that printing the image above onto a transparency made a good indicator which would allow light to shine through the lettering. The only problem was that the printer couldn't get a deep enough black. So I figured, print 5 copies of the image, line them up carefully and glue them together to make a transparency 5 times thicker and the black background is really well, black, but light can still shine through the lettering. A piece of thin white paper behind it all acts as a diffuser and then all that's needed is a good bright LED to finish it off.
I've been playing with this and I'll get a photo of a working version up soon.
Monday, 14 January 2013
RaspberryPi micro temperature server, sitting on the mantelpiece serving temperature data out via wireless onto the World Wide Web thingy. Not always on, but if it is, it can be found at
I'm working on making the readings more accurate using a better Python script. The thermistor is (very) non-linear so I'm trying to generate a look-up table to do this quickly.
Saturday, 12 January 2013
Cost? £40 for a big builders bag, must be at least 300kg in there, which is very reasonable. This compares with about £80 for the same weight in coal. The only drawback is you need to go and collect the blocks with a trailer. Of course Ali sweet-talked the supplier into delivering the first order as a favour, but I had to bag it up myself to get it stored.
So there is of course a play-off with this arrangement. That is to say, work and effort, but that keeps me fit and saves me a pointless gym membership. Someone I know said they couldn't live without the convenience of throwing a switch and getting heat, but I figure they're in for a rude awakening sooner or later the way the world is turning. That said, while we still have electricity on tap, I'm happy enough to use it so I bought myself one of these magic little electric saws from Black and Decker. Only cost me £45 and makes light work of cutting up scrap timber, pallets and old flooring for fuel. In the summer I still like to do a bit of cutting and chopping by hand for the satisfaction of it.
I think we will still use coal at night when it gets cold and the pump is running for the radiators. We only have 10 radiators running, but 5 are big doubles and the boiler struggles sometimes to keep them warm. In a slightly smaller house, say with 8 radiators, this system would be incredible.
The next stage in getting off-grid (-ish) is to look at an alternative system for running the pump, maybe using a solar panel, battery and inverter to drive it or something like that or maybe a parallel 12-volt pump. A pump that could somehow be driven off the heat of the stove itself would be something special. I remember years ago seeing a programme on TV where Russian farmers in Siberia were running their Rigonda TV on a 12 volt thermocouple array run off the back of a big range in the kitchen of the dacha. Looked amazing. I love Soviet-era technology, am a Socialist, but never really cared for Stalin.
All morning oil tankers have been going up and down our street making deliveries and I'm just looking at my nice warm cheap Chinese Communist stove and smiling away. Told you I was a socialist.
Wednesday, 2 January 2013
Voila, a remote temperature sensing device that only needs to be in range of the wi-fi access point to serve live temperature data out over the Internet.
The only problem I'm having is setting up the D-Link router to give external access to the RaspberryPi server. I can test everything okay using the internal IP address of the RPi, which I have made static, but until I figure this one out, I can't read the data from Ulan Batur, Tomsk or Easter Island.
I have also managed to get the No-Ip client working in Linux and have a domain name set up so it would be nice to be able to go to my domain, click on a 'Home Temperature' link and see live data. I'll get there eventually.