Friday, 25 November 2016

Scheme-ing with The Gimp: batch photo resizing

Gimp (a.k.a. The Gimp) is an image editor, very popular with Linux users and possibly a handful of Windows users.

It includes support for scripting tasks via Python (which most young programmers think is the bees-knees) and Scheme (which most Computer Science students think is the work of the devil).

Caught between the devil and the deep blue sea, this post focuses on Scheme.

Sunday, 20 November 2016

Checking your internet connection: a simple Gambas project

A few weeks ago I noticed my internet radio was dropping out for a few moments at a time.

Further investigation showed I was sometimes losing the internet altogether.

So I decided to create a simple program to monitor internet availability.

Thursday, 10 November 2016

Phone/broadband filter: using the BT Openreach MK3

I have just ditched my old broadband filter module for an ADSL filtered faceplate, as part of recent building work at home.

It was not delivered with any instructions, so I had to incorporate it into my new wiring scheme using (I dare say) non-standard wiring.

But hey! seems to work, and here are some notes.

Wednesday, 12 October 2016

DHT22: is it damp under my house?

The DHT22 is a low cost sensor which can provide measurements of relative humidity and temperature.

While carrying out maintenance on the ground floor of our house, it became clear that we had damp & ventilation problems below the suspended wooden floor.

So what better way of monitoring the situation than by using a moisture sensor hooked up to a Raspberry Pi?

Monday, 26 September 2016

Raspberry Pi Audit via SSH

The Raspberry Pi only came into existence in 2012, but there are now quite a few models and variants.

I seem to be having problems keeping track of which Pi boards I've installed in which projects.

So I have created a reference list of Pi boards by serial number and version.

Saturday, 10 September 2016

Spots on my photos

Although a few spots on a photo can be fixed by running the image through your favourite photo editing software, the source of the problem should be investigated.

If you use a DSLR, black spots are most likely caused by dirt directly on the surface of the cameras sensor.

I've noticed this problem with photos taken on my Pentax K-30 during the last few months, but only just found the time to take a closer look.

Sunday, 28 August 2016

Raspberry Pi GPIO: Gambas + pigpio library

There are now a number of ways of controlling the Raspberry Pi general purpose I/O.

Libraries such as wiringPi and pigpio are written in the C programming language, but can also be used with other languages including Gambas.

I have covered wiringPi previously, and this short post is just a basic introduction to using the pigpio library with Gambas.