Saturday 30 August 2014

RaspberryPi + DS18B20 Temperature Sensor

The DS18B20 is a low cost, simple to use, 1-wire temperature sensor which is ideally suited for use with the Raspberry Pi.

Up to 10 of these sensors can be wired in parallel to a single Raspberry Pi GPIO pin, each giving a reasonably accurate indication of temperature.

The current Raspbian image includes support for these devices, so its quite easy to get them up and running.

Wednesday 27 August 2014

The Linux /sys Directory & the ASUS Backlight

The /sys directory is a bit like the /proc virtual file system which I discussed in my last post.

Continuing the "everything is a file" approach, the /sys directory gives you access to many system components and their parameters.

My prime consideration is whether I can control the display backlight on my laptop.

Wednesday 20 August 2014

The Linux /proc directory

Within the Linux file system there is an unusual directory.

It contains apparently empty (0 bytes) files, and includes several numbered sub-directories.

So what's that all about?

Tuesday 12 August 2014

A Better "Automatic Light" Controller

This may be one of the most ridiculus, unnecessary projects I've ever got involved with.

But sometimes when an idea takes hold, it becomes difficult to shake off.

The idea is to calculate sunset using a SINE function, and use this as the basis for controlling an outside light!