Monday, 16 December 2013

RaspberryPi Wifi: Slow To Connect

I've just wasted 20 hours of my life trying get wifi to work on a Raspberry Pi.

All I had to do was follow a previous post, and it should have worked straight away. But life's not like that!

The cause of my problem was rather unexpected, and the solution couldn't have been easier.

Friday, 29 November 2013

BirdBox Activity Counter; what can we expect?

Fitting a sensor to the entrance of a garden bird box can provide you with additional data.

But what can you expect this data to reveal about your little feathered friends?

Prompted by ConwayChallenger's recent Blue Tit Monitor, I've just been taking another look at some bird box data from spring 2011.

Sunday, 24 November 2013

BirdBoxPiCam 2014; #3 Camera Modification

The RaspberryPi camera board is a great accessory, but the lens does not give a wide enough viewing angle for use in BirdBoxPiCam 2014.

So this is how I modified the camera assembly to fit an M12 board lens.

The first step is to remove the existing lens from the Pi camera without breaking something.

Friday, 22 November 2013

Don't Waste Power With L.E.D.s

I've been playing with a mixed bag of white LEDs to work out how many I need to illuminate BirdBox 2014.

As this project is battery powered, I want to minimise power consumption where possible to extend battery life.

Like all 5mm LEDs, there is no obvious way to determine what exactly they are (i.e. there are no part numbers). And as this is a mixed bag, I need to sort them by type before including any of them in my circuit.

Saturday, 16 November 2013

BirdBoxPiCam 2014; #2a Activity Based Power Control Details

Following on from an earlier post, I now have a prototype circuit undergoing testing.

This seems to be behaving as expected, and draws very little current when in standby.

Just to recap, this circuit will power-up my RaspberryPi when activity is detected at the entrance to a bird box (e.g. a bird or an insect breaking the beam between an infrared source and a detector).

Tuesday, 12 November 2013

What is the difference between a Mapped drive and a simple network share?

The popular internet answer appears to be "very little".


But if you are trying to install crappy educational software on a Windows network, you may need to create a mapped drive on any local computers to get it to work.

As I discovered this week, some Windows applications appear to be written such that they expect a mapped drive, rather than simply allowing a user to use a straightforward path to a server shared folder.

Friday, 8 November 2013

Maplin's RaspberryPi GPIO Breakout Board

Just bought one of these little kits to connect my RaspberryPi to a breadboard.

Well, it was cheap...only £3.39.

I was actually looking for a set of jumper leads, and wondering whether I needed male-female, female-female or some other sexual combination, when I spotted this kit from Maplin.

Wednesday, 6 November 2013

RaspberryPi Case; add a GPIO slot

Our Computer Science students have just started hanging components on the RaspberryPi GPIO.

However, the nice cases that protect the RaspberryPi also make it difficult to connect wires to the P1 connector.

Rather than removing the lid from all boxes completely, I decided to cut a slot in the top, just large enough for nimble young fingers to connect insulated jumper wires.

Class Notes; #2 Using Breadboard for the Flashing LED Circuit

Teachers having to train themselves for the new English Computer Science syllabus, have a lot to learn in a short time.


Many have no experience of handling and working with electronic components, as I recently discovered.

So this post expands upon my earlier post: How To Drive LEDs From A RaspberryPi, and is taken directly from my class notes produced for young Computer Science students.

Sunday, 3 November 2013

RaspberryPi GPIO; Using Gambas

The digital IO on the RaspberryPi is very useful for reading switches and turning on relays, lights and driving small motors....

...and controlling the digital IO with Gambas turns out to be really easy.

Here is a very basic example which makes use of the wiringPi library written by Gordon Henderson.

Friday, 1 November 2013

Class notes; How To Drive LEDs From A RaspberryPi

I was asked recently to help with a RaspberryPi training session for a group of young Computer Science pupils.


So this post is simply the hand-outs from this session.

BirdBoxPiCam 2014; #2 Activity Based Power-up & Power-down

Although the power drawn by the RaspberryPi is very low for a computer, its still significant for battery powered equipment such as my bird box monitor.

So here is an idea to reduce power consumption during periods of inactivity.

During the early weeks of the nesting season, visits by birds to garden nest boxes may be infrequent. Typically here in southern England, garden birds may start checking out nest sites during February, with more activity running into April, when nest building typically gets under way.

Wednesday, 23 October 2013

RaspberryPi: keeping time without the internet

The RaspberryPi does not have a real time clock (rtc) so normally requires an internet connection to reset the time and date from a time server.


For my BirdBox 2014 project I need to be able to time-stamp files & data, but it would not matter if the system time was a few minutes out either way, so I have been considering the options.

One popular solution is to connect a small rtc board to the RaspberryPi. These boards are small, low cost, and include a lithium backup battery.

Sunday, 13 October 2013

BirdBoxPiCam 2014; #1 The Plan

I bought my first Raspberry Pi mid-2012 with the idea of using it with a bird box camera.


Unfortunately there were problems with the EzCap video capture module driver, and I have still not been able to get this going.

However, now armed with a PiCam I'm hoping for better luck with my new project.

Friday, 27 September 2013

How to quickly (and safely) defrost the freezer

So, some clown left the freezer door open last night, and now you have ice, lots of ice.

Or if you've been away for the weekend and left the door slightly ajar, you now have an alpine glacier running through your kitchen!

How do you defrost a vertical freezer quickly, before your valuable stock of burgers go all mushie?

Saturday, 14 September 2013

Lubuntu Keyboard Shortcuts

The one thing I hate about my lovely ASUS X401A laptop is the touch-pad.

Its just a plastic rectangle that clicks when you press along three of the sides.

I guess there are two problems with my touch-pad:-
  1. Clicking the mouse tends to move the cursor, so I often select the wrong menu option or highlight the wrong text
  2. When typing, the cursor sometimes moves, so text gets inserted in the wrong part of the document (maybe my hands get too close to the touch-pad)
Since the laptop boasts "...palm proof technology..." I suspect my problems are due to either the Linux touch-pad driver, or its configuration settings.

Thursday, 29 August 2013

A Simple RPi Music Box

Do you have a Raspberry Pi you are not using, or (like me) have a Pi which is only used infrequently, just to try out ideas?


Why not connect it to your stereo and put it to use as a music box.

One of my RPi boards is just used for the occassonal experiment. So I thought I'd load my music files onto an unused 4GB sd card and put this Pi to use.

Thursday, 25 July 2013

Second-hand cars: the cost/mileage trade-off

Our current car (now our only car) has clocked over 100,000 miles, so time to look around for a replacement.


How do you choose between cars of the same make, model and year of manufacture, but with different mileage?

If you choose to buy a car based upon colour, its "babe-magnetic" rating, or just gut instinct, then there's probably little point in reading this post.

But if you want to reign in your initial enthusiasm with a few numbers on a on!

Sunday, 21 July 2013

Yongnuo Wireless Remote Control WR-159

We just bought one of these little wonders for a Canon 1100D. Great price, nice box, but no instructions.

OK, so it may not be the most difficult bit of tech, but I see others on the net searching for an instruction manual, so this may help someone.

I couldn't find a "WR-159" on the Yongnuo website, but they make a YN-159.

Friday, 12 July 2013

Beginners Guide To Updating Your Raspberry Pi

The software associated with the Raspberry Pi is improved, modified and re-issued very frequently.


So even if you purchased your Pi with a pre-installed SD card, sooner or later you will want to update it.

These notes are aimed at those new to the Pi, and written for Raspbian, which is the main (recommended) operating system for the Pi.

Tuesday, 28 May 2013

MakerBot Replicator: Print Quality #3

We recently invited a guy into our organisation to conduct basic training on our MakerBot Replicator 3D printer for a bunch of department heads and other interested staff.


He also gave our machine a bit of a tune-up which has considerably improved print quality.

This post follows on from three previous posts: Replicator, Print Quality & Print Quality #2.

Friday, 12 April 2013

Exploring the ICBIT Bitcoin Exchange API

Just two weeks ago I knew nothing about Bitcoins, and practically nothing about JavaScript.


But having been asked to look at the ICBIT API I now know a little about both.


This post won't describe Bitcoins (start here) or teach you how to program in JavaScript (maybe start here). Its just about the ICBIT api (start here) which enables you to build applications centred around the ICBIT Bitcoin Exchange.

Thursday, 7 March 2013

Configure Wifi on Raspberry Pi

Well, I got myself a nano wifi dongle from Amazon, plugged it into my Pi, followed an on-line tutorial, and then.....Nothing!


It was one of those jobs I thought was gonna be real easy, because everyone was doing it.


So I just had to pour myself a glass of red, then decide on a logical approach to diagnose the problem.

Friday, 8 February 2013

Using A Bird Box Camera: #3 MythBusters

One thing I particularly enjoy about observing garden birds, is witnessing behaviour I've never seen before.

Even better, is when the experts say that a certain kind of bird always does this, but you see one doing the opposite.

When I was a kid, the natural world was expressed in very simple terms. The Lion was the king of the African jungle.

But thanks to hours of observation and filming, often under very difficult conditions, we now know that hyaenas and even buffalo sometimes get the better of lions. And that the largest African animal (the elephant) has to run away from one of the smallest creatures (the bee).

Friday, 1 February 2013

Robin Box 2013: Our First [Avian] Visitor

There have been regular nocturnal visits to our robin box by mice since the 9th January.


The mouse or mice in question are probably just foraging for food, as there does not appear to be any attempt to set up home.

But on the last day of January, our camera captured the first bird to visit the box this year ....a robin.

Wednesday, 30 January 2013

The [not so] EasyCap for Linux

An EasyCap is a USB device that connects a composite video source (like an "analogue" cctv camera) to a computer.

The name "EasyCap" is not really a product name, because there are so many companies making copies of the original device. In fact one company (ClimaxDigital) got so fed up with the number of bad copies in circulation, that it change its branding to EzCAP, and more recently, dropped the name completely.

So you don't really know what you are getting when you order one of these. Its only when you connect it to your Linux computer and type "lsusb" that you discover what is inside.

Wednesday, 23 January 2013

My Smart-arse Sony TV

Just before Christmas I finally plucked up the courage to get rid of the huge TV in our living room.

This must have been one of the last TVs with a proper 4:3 Cathode Ray Tube (crt) that Currys sold. It was enormous.

The neck of the tube stuck out the back so far that we had to sit in the drive-way and watch the TV through the window. It was either that or wedge ourselves into the 10inch gap between the TV screen and the wall. But with our noses pressed up against the screen, it was only possible to take in about 20% of the action.

I hate throwing away working machines, but no one was interested in this fully functional monster. So I loaded it into the back of a truck and took it to the local tip.

Saturday, 12 January 2013

Using a Bird Box Camera: #2 Alarms & Recording

So you've installed a camera in your bird box and you can now relax and wait for your first visitors, and your first exciting glimpse of the private lives of garden birds.


But wait a minute! You don't have the time or the patience to sit in front of your tv, staring at a never changing image, waiting for something to happen.

If you are to avoid going crazy, you need a strategy. So here are a few suggestions.

Wednesday, 9 January 2013

Robin Box 2013: Our First Visitor

The 2013 nesting season wont really get underway for another couple of months, but I've already switched on the system.


Unfortunately, the old Compaq computer that is at the heart of the system didn't want to start, so I had to wheel-in a spare.


For 2013 we will probably only have one camera equipped bird box, our open fronted Robin box. This has been very successful in previous seasons, and in 2012 a pair of robins had two sessions, laying 5 eggs each time, raising 9 chicks successfully. They were all set for a third attempt, but unfortunately one of the adults just disappeared.