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.

Friday, 26 August 2016

Raspberry Pi: headless, windowless file management

I have a number of Raspberry Pi music players that I need to add more tracks to from time to time.

As these players only boot to text (not a desktop) I can't use folder shares or VNC to access the file system.

Fortunately there is another very easy way. I can browse the file system by using secure shell file transfer protocol (sFTP).

Tuesday, 23 August 2016

Using Sockets with Gambas

Sockets are defined as communication end-points, and relate to a means of computer comms using IP addresses and ports.

Sockets are generally used to send data between two computers on a network, but may also be used to communicate between two programs on the same computer.

This post provides a simple introduction using the Gambas Client and Server Socket components.

Tuesday, 9 August 2016

Garmin eTrex: walking with GPX route files

We sometimes go for country walks using simple directions printed from the internet, usually accompanied by very simple maps.

These are OK as long as you don't take a wrong turn or stray off the correct path for some reason.

Although I cannot install topographical maps on my Garmin eTrex 10, I can use Route files.