All posts by Kevin

My Raspberry Pi MeMap

So it’s been a year since the Raspberry Pi was launched and what have people done? Well quite a lot actually. I got my Raspberry Pi in July not with any great plans, although a tweeting doorbell has always been a consideration, I played with it for a few days but then the fact i had to unwire sky to use our only HDMI cable actually got me down.

Around about Christmas I bought a HDMI cable! and I had an idea for my Raspberry Pi, a MeMap (totally making that name up) – I’ve always liked the idea of getting a Harry Potter style Wesley clock to track where I was and Indeed you can get them John McKerrell makes the WhereDial and is Liverpool based as well – but for me having the Rasbperry Pi is all about hacking your own thing, being able to make something i can point at and say “I made that”.

I thought about clocks and dials pointing to mortal peril will always be cool, but it was the Large A-Z map of Liverpool I had randomly hung in the hall that gave me the idea. I could go all retro, and actually light up points on a map.

In our house we are big users of Google Latitude. Its always turned-on on our phones and we can see where each other is at any point and no it’s not creepy it’s actually really useful, especially if your expecting a lift 🙂 , so the idea of taking the web based map and retro fitting it back to a paper map appealed to me.

The Hardware

the Mess of wires that tell you I'm no hardware expert
the Mess of wires that tell you I’m no hardware expert

It’s not a complicated build my map, and it’s a very messy one, I’m not expert at this, So after much hackery, i have 6 LEDs soldered to a circuit board and connected via a AdaFruit Cobbler to the Raspberry PI pins.  it’s a bit of an extravagance , i should have really soldered a cheep connector to the board, but my soldering isn’t that good so i gave myself some space with the cobbler, besides what else am i going to use if for?

The Code

Now i am a software Geek really, so writing the code wasn’t the difficult part for me. using the Google Latitude API and a bit of Python, the raspberry pi checks every minute to see where i am.

Google latitude gives is co-ordinates (latitude and longitude)  and I have a configuration file, that details a set of locations and the range that I need to be in for it to count – so for example within 50 meters of my house and i am home – it’s good to have the range because there are places like the office where the accuracy can be less, probably all the tall buildings.

With the LEDs connected, all the code has to do is use the Raspberry PI GPIO library, to light up the light where I am – and if I’m not anywhere the lights are, then just blink the last place I was.

My MeMap

MeMap InPlace
MeMap InPlace

So now my raspberry Pi is sitting behind the map in the hall, lighting up my location, it’s all great except i never actually see it light up anywhere but home. the Kids think it’s fab mind

Other Stuff

I do have the RaspberryPi doing other things, not as physical as the map,

1. Every weekday morning at 7am, the RaspberryPI emails me a customized weather report (based on Metoffice API) for my cycle in and our of work. telling me if i’m going to get wet and more importantly if it’s a headwind or tailwind.

2. the Raspberry Pi now have the weather station plugged into it. a certain times of day it tweets the weather to the thejumps twitter account, it also ftp’s some graphs to the internet but that’s been a bit temperamental at the moment.

Nerdy Details

it strikes me as i wrote this that all the nerdiness isn’t actually on the internet – I think I’ll go off to github later and upload the code it’s not complicated, it just has load of API keys in it i need to strip out

thoughts on account management

Seems timely – you can get full on password managers; I never find them to useful but – by no means a definitive guide – Google are better for that

These are just my tips for securing you online accounts, you need to find something that is not only secure but practical, going over the top is what gets most people into trouble writing the passwords down and putting stickers on the backs of phones, you have to weight up the risks and impacts on you versus how hard it is do actually do stuff. In short if you are a nuclear physicist in Iran, you probably want to do a lot more than what’s below.

Some ways to secure your online life a bit more: Continue reading thoughts on account management

Tweeting Doorbell

So I got a shiny Arduino, what am I going to do with it?

Once I’d got the LED to blink, and something to sort of happen when I pressed a button, I looked at my tangle of wires switches and started to think, wouldn’t it be cool if…

The entire internet knew when someone was at the door 🙂 , and it would be even cooler, if they all got the song from pink windmill stuck in their head at the same time. 🙂

The wireless doorbell is a strikingly simple project, many people have done it before, and done better than i could – get a wireless doorbell from your local cheap wireless doorbell emporium, take the bell bit apart, workout what wires make the noise/light work, and plug them into an Arduino. Continue reading Tweeting Doorbell