Saturday, 31 December 2016

PiHut Vs. Edimax wifi dongles

A couple of weeks ago I swung by the PiHut website to order some bits & pieces.


While I was there I ordered one of their wifi dongles, just so I could try to evaluate its performance compared to my Edimax dumpy dongle.


So I've just spent a couple of hours this afternoon running a few tests.

Thursday, 29 December 2016

Garmin eTrex 10: adding topo maps

If you believe what Garmin say, it shouldn't be possible to download topographical maps to the eTrex 10.


In fact the Garmin website doesn't give owners that option unless they have an eTrex 20 or 30 model.


But I've just discovered that it is indeed possible, and now have my eTrex 10 loaded with a nice map covering much of the south-east of England.

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! ...it 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.

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.

Thursday, 28 July 2016

Ethereum: wallets, accounts & contracts

Continuing this short series of posts on Ethereum for absolute beginners, here I discuss wallets.


As with many aspects of the Ethereum World, the terminology around "wallets" often seems strange and ambiguous, with descriptions like "Paper", "Presale", "Multisig" and "Brain Wallet".


However, I really want to concentrate on options which I think are best suited to those new to the subject.

Monday, 25 July 2016

Ethereum: what do you need to know?

How much do you need to understand about Ether and the BlockChain?


There is a mountain of information out there on virtual currency and the BlockChain, but it seems to me that the vast majority is aimed at the initiated.


In other words it is mostly written at a level that assumes you already understand the jargon and have a good understanding of the basics.

Saturday, 9 July 2016

Ethereum: let's buy Ether

There is no better way of learning something than doing something.


So I decided to create a new wallet and buy Ether.


I found the whole process pretty straightforward, once I had selected the most appropriate place to buy Ether.

Thursday, 7 July 2016

Ethereum: my new shiny Ether Bar

At a recent family celebration, I was presented with a shiny copper bar.


I immediately tested it with my teeth, thinking it may be like those metal coins we seem to buy the grand children every Christmas, filled with chocolate.


But this was a solid metal bar, made from brass with a bright copper finish.

Tuesday, 5 July 2016

Raspberry Pi: servo motor control via PWM

Following a question raised in response to a recent post on PWM, I hooked up a small servo motor to a Pi.


The motor in question is a 3 wire jobbie that needs a short pulse to control its position.


This short post explains how to drive the servo motor using wiringPi with a touch of Gambas.

Monday, 13 June 2016

Raspberry Pi: adding extra desktops

As a Lubuntu/LXDE user, I hate many of the changes made to the Raspberry Pi desktop over recent years.


But I have to keep reminding myself that this little single board computer is not targeted towards me.


So this is a memo to me on how to add virtual desktops to a Pi, now that they have removed the Openbox Configuration Manager.

Monday, 6 June 2016

BirdBox2016: everybody out!

Well, I say everybody, but that's not exactly true.


Of the 9 healthy looking chicks which hatched from the 9 eggs laid, we seemed to lose 4 during the last few days.


Now is the time to take a look at the data and present a few graphs.

Pentax K30 + Sigma 17-50mm F2.8 EX DC HSM

A few days ago I took possession of a new Sigma zoom lens.


It is essentially a replacement for the Pentax DA 18-55mm AL lens that people often buy bundled with a Pentax DSLR.


So here are a few comments on the Sigma with a simple comparison to the old Pentax.

Friday, 27 May 2016

Hello 4G, goodbye Freeview

Quite by chance, I spent a few hours last Saturday, lifting carpets and floor boards.


The signal on one of our TVs had been a bit iffy for some time, with a tendency for the picture to pixellate on some of the weaker channels.


I put this down to the ancient, brown, co-ax cable running down from the distribution amplifier at the top of the house, to the Sony in our ground floor middle room.

BirdBox2016: quick update

Things seem to be going well with our blue tit family in our Maple Tree bird box.


The adults have turned out to be very good parents and are working flat out to bulk-up their chicks.


They now only have 10 days to stuff themselves with caterpillars before it will be time to leave the safety of the nest and venture outside.

Tuesday, 24 May 2016

5GHz Wifi: shifting up-band

Every so often I get seduced by the promise of faster wifi with wider coverage from a shiny box with 3 aerials.


It usually ends in disappointment when I discover that the new contender is less stable with lower coverage than my old trusty Netgear DG834G.


However, the latest candidate is not too shabby, and it gives me access to both the 2.4GHz and 5GHz wifi bands.

Tuesday, 10 May 2016

KeePass: easing the pain of passwords

Having to live our virtual lives with a stack of user names and passwords is a real pain.


I guess many people will use the same password, or the same password root and just add a new suffix if forced to change (eg. peterpassmore2016).


What with user leaks (where user-error allows passwords to be revealed) or company leaks (where a company accidentally releases user account details), we really should take internet security more seriously.

Friday, 6 May 2016

BirdBox2016: incubating 9 eggs

The local weather has certainly improved over the last few days, with today exceeding 27'C (if my pressure/temperature monitor can be relied upon).


Our blue tit pair seem to have produced 9 eggs, and the female has started sitting on them.


And our first female Emperor moth emerged yesterday and attracted a mate this afternoon.

Wednesday, 4 May 2016

HP455 Laptop: good news for Linux users

If you bought an HP455 laptop running Ubuntu, you may know there are problems updating the OS from the old 12.04LTS version supplied.


As this laptop relies upon special HP packages, it can be extremely difficult to upgrade, while still maintaining functionality of wifi, sound and function keys.


However, with the release a few days ago of version 16.04LTS, this may have all changed.

Friday, 29 April 2016

BirdBox2016: eggs at last

This season has certainly been unusual compared to the 7 previous years.


Following an unusually mild winter we have had to suffer a lot of cold, and often gloomy days during April.


So while we have generally noticed eggs appearing in our nest boxes in early April, this year we have had to wait a few weeks longer.

Wednesday, 27 April 2016

Midori as a Site-Specific Browser

A Site-Specific Browser (SSB) is a program or application that is dedicated to loading and exploring a single web site.


This allows a user to simply click on an icon and go straight to a web site, often using an interface with minimum functionality.


But my main interest in the SSB approach has more to do with security than ease of use.

Tuesday, 26 April 2016

Inexperienced parents: I just don't buy it!

A common reason offered for the failure of a pair of garden birds to successfully raise a brood is that "...the parents are probably inexperienced..."


This view seems to be so widespread, that even the good folk on BBC SpringWatch have been known to offer this explanation.


But surely this is another example of people dreaming up a simple theory without thinking things through...

Monday, 18 April 2016

KitchenPi: an internet radio for my kitchen

We needed a radio in the kitchen to replace our Bush DAB/FM portable which has put in good service, although DAB reception in our area has never been great.


As space is at a premium, I wanted the new radio to take up as little space as possible.


So I came up with the idea of building something that would fit under the eye-level kitchen cabinets, behind the decorative molding.

Saturday, 9 April 2016

BirdBox2016: the odd couple

From previous years, it is generally the first 10 days of April when nesting tits complete their nests and the first eggs appear [at least in our garden].


A pair of blue tits took over our Maple Tree bird box early in March, and have been visiting regularly right through the last 4 or 5 weeks.


However, their behaviour has not been typical from our experience of observing via box cameras since the start of the 2009 season.

Sunday, 3 April 2016

Raspberry Pi 3: a Linux desktop computer?

I now have a Raspberry Pi 3 in addition to my other 10 Pi boards.


This is my first Pi 3 and it does appear to be even quicker than my Pi 2.


But is it fast enough to be used as the basis for a Linux desktop computer?

Monday, 28 March 2016

Raspberry Pi audio vs. Adafruit USB audio

Many people on the internet comment about the poor sound quality of the Raspberry Pi audio output when taken direct from the 3.5mm jack socket.


One alternative is the Adafruit USB audio adaptor, which provides a mic input and headphone output.


Both the Pi jack and Adafruit audio outputs sounded a little harsh to me, so I decided to do a few checks using sine waves and a scope.

Friday, 25 March 2016

The NJM2073D: an amp for the Pi

The NJM2073D is a low cost, easy to use, audio amplifier chip with a maximum power of about 2 Watts.


It can be used as a stereo amplifier for portable devices like a music player or a radio, and is available for just over £1.


I have a couple of Raspberry Pi applications that need audio, so this device looks like a good option.

Saturday, 12 March 2016

BirdBox2016: what's happening?

There has been plenty of interest shown by a number of local blue tits in both of our Pi powered bird boxes.


I've also added some enhancements to our bird box monitor which sits in a corner of our kitchen and raises the alarm if a box is triggered by a visitor.


It is the 12th March, so we may only be 2 or 3 weeks away from some real nest-building action!

Sunday, 6 March 2016

Pi Unicorn Hat: as a photographic strobe light

This Hat sits on a Raspberry Pi and contains 64 LEDs in an 8 x 8 grid format.


The documentation says that the LEDs are very bright "...bright enough to cause eye pain... possibly retina damage..." ...so I wondered if they had a use in photography.


This post details some experimentation, some Python code, and a few photos.

Wednesday, 2 March 2016

BlissFlixx: wifi config & user information

I was thinking recently about how I might send a configured BlissFlixx SD card or complete system to a friend.


How easy is it for someone to configure and use?


This led to a bit of Python coding, as I attempted to make wifi configuration just a little bit easier.

Tuesday, 23 February 2016

Raspberry Pi: stuff I don't need in Jessie

They pack a lot of stuff into the current Raspbian Jessie Full distribution that I have no use for.


The down-side to this is two-fold: a lot of precious space is taken up on the SD card, and updates can take longer than necessary when any of these unused apps get updated.


So this post is just a place to save my list of packages that I'm happy to remove.

Sunday, 21 February 2016

Tontec 7 inch LCD + RaspberryPi

I bought this LCD about 10 months ago for £35, so its about time I did something with it!


I've half an idea that I could use it in the kitchen to monitor the video feeds from my bird boxes.


The first problem is how to mount it into a panel, as the LCD module does not have any mounting points or lugs.

Tuesday, 16 February 2016

BirdBox2016: 2nd Pi Power box deployed

We fixed our second Pi-powered bird box to the Canadian Maple in our garden yesterday afternoon.

In the first few hours this morning, bathed in glorious winter sunshine, we had plenty of interest from a blue tit or two.


So this is a very promising start to the 2016 nest box season.

Friday, 12 February 2016

PWM on RaspberryPi with Gambas

The Raspberry Pi has a PWM (pulse width modulation) mode which can be put to use in Gambas with the help of Gordon's wiringPi library.

 

The wiringPi library allows access to the hardware controlled PWM feature which is output on wiringPi pin 1.


So here are some notes and a small Gambas test program to help explore its capabilities.

Wednesday, 3 February 2016

Whatever happend to the web browser?

It is over 20 years ago that Mosaic and Netscape opened our eyes to the internet.


By the end of the 1990's it looked like a tick-in-the-box. There were lots of different graphical web browsers and they all seemed to work and show web pages in much the same way.


So what a surprise to find in the 2010's that so many of the leading brands are just, well, broken!

Tuesday, 2 February 2016

BirdBox 2016: the season has started

I attached my PicaxePi powered bird box to the side of our pergola on Saturday afternoon.


When I checked the system on Sunday afternoon, I found it had been tripped five times.


So has the 2016 season started?

Friday, 29 January 2016

Barometric Pressure, the BMP180 & Gambas

Some birds and other animals are thought to be sensitive to changes in atmospheric pressure.


This year I plan to monitor & record pressure, in addition to activity in and around my bird nesting boxes.


The BMP180 is a very small, low cost sensor which can be used to determine temperature and atmospheric pressure. ...looks like a great place to start!

Saturday, 23 January 2016

RoboBuggy and Me

I received another bag-of-bits type Christmas present in 2015.


This one contained nuts, bolts, bits of acrylic, wheels, motors and a battery holder.


Despite being involved with electronics for over 50 years, I have zero experience with robotics.

Wednesday, 6 January 2016

BlissFlixx on RaspberryPi

A few days ago I stumbled upon a video media application for the Raspberry Pi.


I've tried others in the past like XBMC, and I don't really like them. But BlissFlixx is different.


I have only been playing around with it for a couple of days, and I'm already hooked!

Monday, 4 January 2016

The Murder Mystery Game: create a Facilitator

The Murder Mystery Game is strictly low-tech and can be played without any real equipment.


But you do need a Facilitator, and this normally means one person setting the game up, but not playing the game themselves.


However, the role of the Facilitator can be replaced by a computer running a simple program.