• Year Notes: 2015

    Last year’s notes ended with a cliff hanger, would I take a permanent job at Axon Vibe or would I not? Well the year began straight away with a visit to head office. Flying out to Lucerne in Switzerland on the fifth of January. This was actually my wife’s first day back in work after being off for over a year’s maternity leave. It was unfortunate to have to leave her to sort out our daughter during her first week but I did at least get a later flight so that I could help get Evie to her first morning in nursery.

    View from the office terrace

    After much consideration I ultimately decided to take the job at Axon Vibe. I was intending to continue working for them so it’s not like I was looking for other clients, and the money was such that I wasn’t losing out by being a salaried worker. By this point I’d already agreed that I would have my daughter on Friday afternoons so I ultimately decide to work Monday - Thursday but to keep Friday for myself. That would allow me to keep working on my own apps or even doing small amounts of client work on Friday mornings. The view from the terrace (see above) certainly didn’t hurt either!

    I wasn’t going to mention too much about what we did at Axon Vibe that year as very little of what we did then has survived. We took some time to work out what our key offering would be, sometimes focussing on business to business applications, and at others trying to develop public facing apps. One interesting thing was that we took on a number of developers and a designer who all worked from DoES Liverpool. By the end of the year we actually had 4 people all working from Liverpool. That was great to see, even if I did find it a little strange sharing an office with colleagues! We also enjoyed a great week in October when we managed to persuade colleagues from Cirencester, Norwich and Edinburgh to visit while we worked on new developments.

    Way back in 2011 I’d actually taken over the running of a monthly event that would have geeks meeting up in a local bar on the last Tuesday of the month either just for a social meet-up or to hear someone talking about some technology or, well, anything that happened to interest them. GeekUp was a venerable event that started way back in December 2005 in Manchester. Over time the event became more popular and drew in people from surrounding towns, Liverpool included. I attended my first event in March 2017, gave a talk on OpenStreetMap at the following event and then was glad to attend the inaugural event in Liverpool later that month.

    Running for so many years, GeekUp was such a great way for similarly minded folks in Liverpool to connect. Most of my friendships in Liverpool can be traced back to GeekUp, especially if you consider that I would never have co-founded DoES Liverpool if I hadn’t met Adrian McEwen there. While I enjoyed attending GeekUp I found I wasn’t the best at running it. It was easier when we met in a bar as if there was no talk you could easily just chat and have a drink. It’s amazing how a simple schedule of “last Tuesday of the month” and perhaps the odd “Are you going to GeekUp?” on twitter would keep the event going quite well. GeekUp ran for four years meeting in 3345 (now “The Attic”) on Parr Street. On one of the last meetings there we found the room had been double booked (I’m sure with UKIP!) and it turned out we no longer had the booking at all. As we were in the process of setting up DoES Liverpool, and we were planning to host events there, we had a single meeting in Leaf on Bold Street, before moving the event to DoES.

    This change really affected the dynamic of the event, it was more difficult to get into the space and when you arrived you found a bland room of desks so it was quite different to meeting in a bar. We actually managed to continue for four more years but I struggled to get around to finding people to talk. Then in 2014 when I did manage to arrange and promote in advance a great line-up of speakers, I struggled to attract an audience! In the end I decided that life was complicated enough without the monthly stress of finding a speaker so 2015 was the year I brought the whole thing to an end. Although I don’t really get time to go out so much these days it does seem like Liverpool is missing a general geeky social meet like this now so it’s a shame there is no GeekUp, but there’s nothing saying someone couldn’t take it on again in the future!

    I continued with my running this year too. Living just 4km away from DoES Liverpool it’s actually an easy and fairly short run to get into the office and I’ve tried at times to make it my primary way of commuting. I haven’t managed it often but have a few times managed to run there and back for the four days I would be in the office. No Half Marathon this year but I signed up for the Spring 10K around Sefton Park and managed to beat my personal best of around 46 minutes, I wasn’t too confident as I hadn’t done much speed training but was very happy when I blew almost 3 minutes off my record!

    I tried to take up gardening as a hobby to brighten the place up. I even planted potatoes so that we’d get greenery and useful, tasty potatoes. Though at times the potatoes seemed like they were trying to take over the DoES Liverpool meeting room we didn’t really have a very prosperous harvest and it felt like the time and effort could be better placed!

    DoES Liverpool could still benefit from some more plant life but there definitely needs to be a plan for maintenance for this sort of thing! 🌻

    Hm.. anything else happen in 2015? Well we made this little announcement:

    As we settled into our new life with work and nursery and with Evie being such a good sleeper we decided that we might actually like to have another little person around the place. Funnily enough while Evie had actually come 10 days late Ethan actually came along exactly on his due date!

    While Ethan seemed originally to be feeding okay we ended up having similar troubles with him losing too much weight and being harassed by mid-wives. After a week of problems we went along to an infant feeding clinic only to be told that Ethan had a tongue tie. A tiny piece of skin was stopping him from being able to move his tongue freely and causing him problems with feeding. Unfortunately our options were limited to waiting 2 months for an appointment in Alder Hey or trying to get it done in Chester Hospital. There was also the option of going private but we really didn’t think we should have to do that and also of the standards of care we’d receive. Being so close to Christmas we were quite concerned about whether we’d managed to get it done before the holidays so we were very happy when we got an appointment for the 23rd December. Poor Ethan ended up picking up a cold meaning the nurse almost couldn’t complete the tongue tie snip, and as it turned out had probably missed some as it really didn’t make much difference to his feeding. It seems ridiculous having to wait three weeks for something that should have been picked up and fixed while he was still in the hospital, and that the much vaunted and well-funded Alder Hey couldn’t do anything about it for months. Obviously we can’t be sure that dealing with it straight away would have reduced the problems, but it would have given Ethan a much better chance and given my poor stressed wife one less thing to worry about!

    I feel I should finish on a lighter note though so let’s back-track to October, we’d been invited to a Halloween party and I couldn’t think of what to go as. My wife spotted a Jack Skellington costume in the shop and came up with the great idea of combining it with one of my old Santa Dash costumes, resulting in this great result:

  • Year Notes: 2014

    So obviously after the events at the tail end of 2013, this year was mostly spent dealing with the fact that we now had a tiny (not so tiny) baby to look after! Work-wise I’d stupidly taken on two new clients just before baby came along so while they were freelance clients who were aware of what was happening, it did mean I had some worries about making sure I could do work for them. In the end one of them tailed away to nothing within a few weeks of the new year and the other was just a week or so’s work that I managed to get in while baby was napping.

    In retrospect the newborn stage is actually something of a calm before the storm as they do tend to sleep a lot. We had some issues around baby’s feeding and weight gain which the midwives dutifully freaked us out over but after a few months she did start putting on weight better. In fact once we weaned her onto food, which with perhaps rose-tinted hindsight went pretty well, she started putting on plenty of weight.

    mugged for milk

    The “week’s work” was quite an interesting iPad app and ultimately developed into a continuous 2 days a week. Without going into too much detail it was tourism based and involved having the app open while you were driving a car. It proved quite tricky to develop and test due in part to literally having to go out and drive in a car to get any useful test data. Also my clients were in London and there was times when they would upgrade the app, drive to central London, try to launch the app and find it insta-crashed. The fix was to delete and reinstall, not so easy for a multiple hundred MB app when you’d already gone to the location. With this and another client I’ll get to shortly I learned a lot about the benefits of automated testing, automated smoke testing and continuous integration. The testing tools at the time were not so good as they are now in Xcode but if I had a good method to simulate a drive, and to do smoke tests every time I committed code I could have avoided many of the problems I encountered.

    A few months into the year when I was mainly working on some updates to CamViewer and making further small changes to the iPad app I just mentioned I was approached by John Fagan who I used to work with at Multimap. He was wondering if I’d be interested in taking on a full time role at the company that he was working for - Axon Active. I’d not really been interested in full time roles but in fact as this was a foreign company I would be treated more like a contractor, and the money was pretty decent. Ultimately I told John no, only for him to suggest that I might work just a few days a week for them instead. When I mentioned these talks to the people I’d been engaging with on the other app they jumped at the chance to grab my other free days and so I ended up with 5 paid days a week split between Axon Active (3 days) and the other client.

    Looking back on my tweets from the year I see multiple mentions of running. I’ve never really mentioned running on this blog which is quite bad because it’s become a regular part of my life. In fact in 2013 I ran my first marathon, a milestone I forgot to mention in the previous blog post! In 2014 I ran the same race again but found it much more tricky to fit in training around childcare, I mostly did best efforts at the training plan I was using but ended up with a decent result. While in 2013 I managed an awesome 1:40:00 for the half, I managed to follow it up in 2014 with a very respectable 1:43:25. In 2013 I ended up having real issues with my IT band, causing me to limp the last few miles. Annoyingly in 2014 I actually felt much better and had no issues such as this, but then faced a headwind for the same last miles! I could quite possibly have improved my PR if it wasn’t for that.

    With Axon Active I was working on a small project they’d been developing around taking in various items of data that would be made available on an iPhone, uploading them to a server and from there deriving information about patterns in the way you live and your future plans that we might be able to help you with. At the time we pulled in location and calendar events and would do things such as suggesting a place you might go to nearby for a quick lunch or let you know about travel options for your calendar appointments.

    Axon Active are a Swiss company but most of the people working for them were remote. At the time we had people in France, Edinburgh, London, Brighton, Manchester, even Russia! This allowed me to keep the flexibility of working from DoES Liverpool which was very handy. We would meet every 3 weeks in London for sprint planning and every 3 months for a trip to head office in Switzerland. This worked really well with the new baby, I could choose to work from home or from DoES Liverpool most of the time and the trips to London weren’t too tricky. Having to be away for a week wasn’t so great but it also wasn’t so often. We had plenty of support from my mother in law, Anne, so that made sure I was mostly not leaving my wife home alone with the kid. Also helped that my daughter got really quite good at sleeping from as early as 6 months!

    The project at Axon Active was initially just a side-project for an 8 person team but as the year progressed the company really saw the potential of what we were doing and it culminated in a new UK based company being formed at the very end of the year… but that’s really a story for 2015.

    Again looking back at my tweets I see that after some discussions with Patrick Fenner I had him and his wife Jen Fenner, through their company Deferred Procrastination, help me with a new design of the WhereDial. They actually engaged an old friend Sophie Green to prepare some artwork for the device while Patrick and Jen looked at improving the functional design and the production method. They developed a way of using screen printing to allow much faster printing of designs onto the laser cut materials (ultimately screen printing would take seconds where laser engraving could take 15-20 minutes per piece). The resultant WhereDial looked really good and I was quite happy with the results. Unfortunately as I got busier with life and paid work I found I didn’t have the time to progress this so never got as far as selling the new versions. I’ve had them around my house and on my desk over the years and it’s interesting to note that while they do look good, the design is quite busy and the colours quite low contrast so it can be tricky to tell what’s happening from across a room. Something to keep in mind if I ever get around to developing the WhereDial again!

    The iPad app continued on for much of the year, we found it tricky getting the location based stuff working just how we wanted. We were trying to simulate something that a human would do and the clients had a particular level of quality in mind that was hard to replicate. There was also the need for a sat-nav component in the app, we didn’t want to call out to Apple Maps so would have needed to either build a sat nav ourselves or pull in a third party component. In the end this proved particularly difficult to find for iOS leading them to look at Android as an alternative. With my lack of interest in Android and continuing focus on the Axon Active role we ended up parting ways in Autumn. It was a really interesting app to work on but just had some difficulties that would really have required a lot more development resource than me working on my own. I didn’t hear too much from the clients once I handed the code over to their Android developer and I have a feeling that the project stalled around then.

    That’s probably it for 2014 really, once that app project stopped I found it useful having two days a week to do more work on CamViewer and also found the time to make some changes to the Chess Viewer app that I’d been working on intermittently. As 2014 drew to a close my wife started to think about returning to work and deciding what hours she wanted to do. Axon Active were also looking to setup the UK company and were offering people full time jobs, me included. I really wasn’t sure that I wanted to make that commitment, my stance hadn’t really changed from the beginning of the year, but I wasn’t really looking for any more work and the money was still pretty decent even as an employee so it was a hard decision to make. I didn’t make the decision until the first week of 2015 so I’ll make you wait to hear!

    (Let’s finish up with a photo of me ready for the 5k Santa Dash)

  • Year Notes: 2013

    I was tempted to skip this year as I had after all written a blog post that year already, but why not go crazy and write a second one, maybe the 2013 review would have been the first post of 2014 anyway?

    Although I tend to write about geeky work related things on this blog it’s really my personal blog so I should definitely mention that the two major events of 2013 for me were personal rather than work related. We (my wife and I) moved house, and got pregnant! The house move wasn’t particularly planned and just came from noticing a house around the corner from ours that looked interesting, checking it out (awful) but then looking at a few more and deciding that actually we really could manage a nice upgrade, and might need to as we’d be needing more room soon.

    We were lucky that we could afford a lovely big victorian house, which looks nice and provides lots of room for kids and associated “stuff”, but isn’t the best when it comes to heating and having lots of little jobs that need doing. We actually didn’t move in for 3 months after buying it, but still even now have lots of jobs that need doing and some quite large bits of building work we’d like to do, if we could get around to it (making the cellar a usable space and extending the kitchen). Obviously having lots of jobs to do is standard for owning a house but this place definitely seems to take it to another level!

    Also back in 2013 I took on a summer student, Elliot. That was a great experience even if I hadn’t necessarily prepared well enough for having him around. I ended up giving him all sorts of different bits of work to do including upgrades to my CamViewer webcam viewing app and upgrades to the WhereDial. He actually did most of the work towards a Wi-Fi enabled webcam that would have used TP-Link mini Wi-Fi routers as much of the brains with a bespoke Arduino compatible circuit board controlling the motor. Unfortunately in the end I didn’t get around to productising that but hopefully he had some fun working on it and got some good experience. After that summer he went back to university to finish his degree then had no problem finding a job. I haven’t caught up with him in a while but I believe he’s still doing well and applying his great versatility to working on a variety of things from back-end server coding to mobile app dev.

    During the summer of 2013 I, with Adrian McEwen, Hakim Cassimally and Aine McGuire exhibited at Internet World trade show in Earls Court, London. That was quite an interesting experience. We were given a prime spot at the entrance to the show and used it to demonstrate a variety of IoT devices including the WhereDial and Bubblino, Hakim and Adrian also promoted their book Designing the Internet of Things. And because spending a week in London wasn’t enough we then spent the following weekend in Newcastle for Makerfaire!

    Makerfaire 2013

    Wow, looking at my notes that was when my relationship with ExamsTutor ended. Unfortunately it didn’t end as well as I’d have liked, they simply decided they did not want to continue the relationship and largely cut off communication. I had owned the IP behind the apps so no further development occurred on those and it looks like they got removed from the app store in Apple’s great cull of 2016 (removing any app that hadn’t been updated in years). A shame to end that way as I’d enjoyed working with them but there wasn’t much I could do once they stopped replying to emails.

    My relationship with 7digital also ended this year, as I recall they were looking to take development in-house which was fair enough. I don’t think iOS was ever really a huge priority for them as Apple’s app store rules made it difficult for them to make any money from the app. I know they continued using my codebase for a few years after, it’s hard to tell if they still do, the app’s structure hasn’t changed too much but it’s quite likely it’s had some restructuring under the hood.

    As mentioned I (and Elliot) also continued working on CamViewer through that year. Interestingly looking at the Changelog that year seems to have been the start of me adding more functionality to the app. At the end of the year I added support for “HD” cameras that use RTSP by integrating a paid-for library. That was just in time for me to use cameras such as this as baby monitors, something I and my wife have both found really handy over the years.

    Pretty much the last thing that happened in this year, Evie was born!

    Actually 6 months old in this picture

    So that’s a review of 2013 done, just 3 more years to cover (assuming I get this done quickly, considering I started this blog post in January (2017) that may not be the case!)

  • New New Blog, New Old Blog

    So I’ve decided to replace my previous blog with a WordPress blog.

    That was the first line I put on my WordPress blog, which I’ve now replaced with Jekyll. The first post on that was in October 2006, so nearly 11 years ago!

    Over the past 11 years I’ve moved away from doing anything PHP, or anything server-side really. I have no particular need of the online editing that you get with WordPress or any of the other features really. I’m also trying to be quite paranoid about what daemons I run on my hosting server. I came across Jekyll (again) as part of a documentation project in my day job and was impressed by how easy it was to use so decided I would start migrating some of my own stuff over.

    My first migration was actually the website for my CamViewer iOS app which was already based on Gollum the markdown wiki so should have been quite simple to migrate (actually it was still a bit of a faff due to different markdown versions).

    I hoped migrating Wordpress would also be easy as so many people use both technologies. As it turned out there was still plenty of work involved. I ended up using two migration tools. The main Jekyll importer didn’t seem to do a great job of pulling the HTML in but pulled all the comments across nicely so I ended up using exitwp and writing a yaml copying tool to pull the comments from one to the other.

    This blog hasn’t actually got any comments functionality at the moment, I figure people can ping me @mcknut on Twitter if they want to make comments but I’ve copied the ones that were on the old site.

    My previous blog made use of whizzy fun modern technologies to allow me to host my entire site on Google Base, Google Pages and del.icio.us. Unfortunately, because it was something I had just knocked up there was no comment support, and of course it did require Java and JavaScript to be enabled in the browser.

    That original blog was quite a weird thing, I tried to make it so that all the content was hosted online. Unfortunately as it was JavaScript based not much has been saved on the Internet Archive. It does seem like all the original posts are now lost but with any luck I’ve got the content… somewhere.

  • Long time no see

    It’s been a very long time since I’ve written anything here. I thought I’d like to write up a small project I did recently, but then there would be a bit of back story, and then a bit more, and oh yes I haven’t blogged in 4 years so I should really do something about that.

    As such I’m going to try to write some year reviews. Not promising to make them in depth but it’ll give me a chance to look back and see what I’ve actually been doing all these years (actually it’s pretty obvious to me given that the last post was 4 years ago and a major thing happened just after that but here’s goes nothing..!)

  • Adding a Wiki to MapMe.At using Gollum

    I recently added a wiki on my MapMe.At site and found it quite tricky to get working and difficult to find just the right information I needed so I thought I’d write it up.

    MapMe.At is still on Rails 2 which seemed to mean I couldn’t install Gollum as part of the site.

    I created a separate Rails 3 project that runs alongside MapMe.At and simply hosts Gollum, using instructions from here: http://stackoverflow.com/questions/13053704/how-to-properly-mount-githubs-gollum-wiki-inside-a-rails-app

    I wanted it to use the user information in MapMe.At’s session hash so switched MapMe.At to use activerecord based sessions and used information on here to make the rails 2 session load in rails 3: http://www.kadrmasconcepts.com/blog/2012/07/19/sharing-rails-sessions-with-php-coldfusion-and-more/

    I’m not actually using the rails2 session as the main session, I just load the information in. I have the following in config/initializers/session_store.rb

    module ActionController
      module Flash
        class FlashHash < Hash
          def method_missing(m, *a, &b;)
    MapmeAtWiki::Application.config.session_store :cookie_store, key: '_mapme_at_wiki_session'

    Then in routes.rb:

    class App < Precious::App
      before { authenticate }
      helpers do
        def authenticate
          oldsess = ActiveRecord::SessionStore::Session.find_by_session_id(request.cookies["_myapp_session"])
          if oldsess and oldsess.data and oldsess.data[:user_id]
            u = User.find(oldsess.data[:user_id])
            email = "#{u.username}@gitusers.mckerrell.net"
            session["gollum.author"] = { :name => u.full_name, :email => email }
            response["Location"] = "http://mapme.at/me/login?postlogin=/wiki/"
            throw(:halt, [302, "Found"])
    MapmeAtWiki::Application.routes.draw do
      # The priority is based upon order of creation:
      # first created -> highest priority.
      App.set(:gollum_path, Rails.root.join('db/wiki.git').to_s)
      App.set(:default_markup, :markdown) # set your favorite markup language
      App.set(:wiki_options, {:universal_toc => false})
      mount App, at: 'wiki'

    I wanted a wiki on the site to allow my users to help out with documenting the site. Adding their own thoughts and experiences and perhaps fixing typos I might make. I’m not sure that’s really started happening yet but at least I have a nice interface for writing the documentation myself!

  • WhereDial Ready to Ship

    A good few years ago I blogged about making a clock that showed location, similar to the clock that Weasley family had in the Harry Potter books. Well now you can buy one! I’ve spent the last year working on the design and getting the hardware ready. Take a look at the photos below and head over to the website for more information on the WhereDial!

  • OpenStreetMap at Social Media Cafe Liverpool

    I gave a talk last night at Social Media Cafe about OpenStreetMap. I actually haven’t been too involved in the OSM community of late so it was nice to get back into it a little bit. It was also good to find that a large portion of the audience was not already aware of OSM so it was nice to introduce it to people.

    You can find the video of Social Media Cafe on USTREAM. The video will be chopped up soon at which point I’ll link to or embed my own talk here too.

    I ended up with 63 slides taking up about 100MB so I’m going to try not uploading it to Slideshare this time, instead I’m going to summarise the talk here.

    OpenStreetMap - John McKerrell @mcknut - Freelance Software Developer

    Why do we need OpenStreetMap?

    • Geodata historically isn’t

      • Current - things change so often maps quickly become outdated.

      • Open - if you know the map is wrong, wouldn’t it be simpler to let you update it yourself?

      • Free - You want me to pay how much for Ordnance Survey data?? Especially an issue when you’ve helped build the map.

    • Wiki is obvious next step

    • It’s just fun

    We make beautiful maps…

    …which we give away

    Beautiful OpenStreetMap map

    It’s not just Liverpool, or even the UK, in the talk I showed maps of the Hague, Washington, DC and Berlin. You can pan and zoom the map linked to above to browse the coverage.

    Some Quotes

    “It’s absolutely possible for a bunch of smart guys with the technology we have today to capture street networks, and potentially the major roads of the UK and minor roads”

    Ed Parsons, ex-CTO Ordnance Survey currently Geospatial Technologist for Google

    “If you don’t make [lower-resolution mapping data] publicly available, there will be people with their cars and GPS devices, driving around with their laptops .. They will be cataloguing every lane, and enjoying it, driving 4×4s behind your farm at the dead of night. There will, if necessary, be a grass-roots remapping.”

    Tim Berners-Lee

    “You could have a community capability where you took the GPS data of people driving around and started to see, oh, there’s a new road that we don’t have, a new route .. And so that data eventually should just come from the community with the right software infrastructure.”

    Bill Gates

    Some big names in technology who clearly think user-generated mapping data is a good idea.

    Isn’t Google Free?

    A lot of people ask the question “Why do we need OpenStreetMap when Google Maps is free?”


    Google Map of Liverpool showing places that are no longer pertinent


    This picture shows a Google Map screenshot that I took on 16th February 2012. In the centre of the map you can see the Moat House Hotel. This was bulldozed in 2005 but still shows up on Google’s map. You’ll also see the Consulate of the United States in Liverpool. This was also closed down some time ago. So you can see that Google Maps isn’t perfectly current (and, for the record, I have now reported these problems to Google).


    Google have launched their own project to map the planet. Map Maker allows people in many countries to edit the data of the map, adding roads and POIs in a similar way to OSM. Unfortunately Google doesn’t then provide full access to this data back to the people who have made it! Map tiles are generated and shapes of the data entered can be retrieved but the full detail of the data is kept by Google. The license offered by Google also restricts its use to non-commercial usage, stopping people who have put effort into creating the data from being able to derive an income from it.


    Though Google’s mapping API is free to use initially they have recently introduced usage limits. Though they claim that this will only affect 0.35% of their customers, it has already affected a number of popular websites that simply can’t afford to pay what Google is requesting. Some examples will be given of these later.

    Google Support OSM

    It would be unfair to talk about the bad parts of Google without mentioning the good. Google has regularly supported OSM through donations, sponsorship of mapping parties and support through their “Summer of Code” programme.

    As do other providers

    It also wouldn’t be fair to paint Google as the only supporter, for example:

    • Mapquest sponsors and supports OSM efforts.

    • Microsoft Bing Maps sponsors and supports OSM efforts, even allowing their aerial imagery to be traced.


    Or, Map as Party (Mapping Parties!)

    The first mapping party was in the Isle of Wight. At the time the only “free” map data available was an Ordnance Survey map that had gone out of copyright:

    Isle of Wight OS Map

    A group of people went to the island for a weekend and collected GPS traces of all the roads:

    And from these made a great looking map:

    We also held a mapping party in Liverpool in November 2007 which allowed us to essentially complete the map of the centre of Liverpool.

    That video shows the traces of everyone involved with the mapping party as they went around Liverpool and mapped the streets. It was built using the scripts referenced on this wiki page

    Editing OSM

    Visit openstreetmap.org and sign up for an account. If you have GPS traces, upload them, don’t worry if you don’t as you’ll be able to help by editing existing data or tracing over aerial imagery.

    Data Model

    • Nodes

      • Single point on the earth - Latitude and Longitude
    • Way

      • Ordered list of nodes which together make up a long line or an enclosed area
    • Relation

      • A method of relating multiple ways and nodes together, e.g. “turning from way A to way B using node C is not allowed”
    • Tags

      • Nodes/Ways/Relations can have key=value pairs attached to describe their properties.

      • Example node tags:

        • amenity=place_of_worship, religion=buddhist

        • amenity=post_box

      • Example way tags:

        • highway=primary

        • oneway=yes

    An online flash editor is available (Potlatch) simply by clicking the “Edit” link when looking at any map on OSM. An offline editing desktop app built in Java is also available, JOSM

    There are hundreds of tags that you can use to describe almost any data, use the wiki to find more information especially the Map Features page.



    This license lets anyone use the OSM maps for free so long as you mention that the source was OpenStreetMap and you share what you produce under a similar license.

    Very soon the license will change from CC-BY-SA to Open Database License which offers similar freedoms with more suitable legal terminology. Do read into it if you think it will affect you.

    OSM in Action

    Nestoria, a popular property website, has long supported OSM. A few years ago they made use of OSM data by using the maps generated from the Isle of Wight mapping party to replace the non-existent data in Google Maps. More recently they have been affected by Google’s plans to charge for its map data and so they have switched fully to OpenStreetMap data and maps.

    CycleStreets is a great website for finding cycle routes. They offer a directions engine that gives detailed descriptions of routes, allowing you to pick between Balanced, Fastest and Shortest routes. They also offer lots more information and a database of photos to give more insight into a journey. The routes they recommend are ideal for keeping cyclists off the busy dangerous roads and onto the quieter safer more direct routes.

    mapme.at is a website that I have built for tracking people’s location. People use it to track places that they visit and journeys that they take. I use it to track everywhere I ever go. Adrian McEwen wrote a script that puts the location of the Mersey Ferries into mapme.at and that’s what you can see in the map above.

    A few years ago I worked with ITO World to create some animations of my data. They created great animations which you can find on my vimeo account but below is one showing every journey I took in January 2010 with each day being played concurrently.

    All travels in January 2010 run at once. from John McKerrell on Vimeo.

    Geocaching is a popular pastime based around GPSes, treasure hunting and maps. Their website used Google Maps and they also had issues when Google started to charge. As a result they have switched to OpenStreetMap too.


    Lots of mobile apps are available to let you use and contribute to OpenStreetMap


    Not being a regular user of Android I can’t recommend any apps personally but there is a large list of OSM Android apps on the wiki and I’ve selected the following based on features they claim to offer.

    gopens and MapDroyd both allow you to browse OpenStreetMap maps on the go and claim to offer offline support, allowing you to view maps even when you’re not connected to the internet.

    Skobbler Navigation provides a full Tom-Tom style satnav for navigating on the go, all based on OpenStreetMap data.

    Mapzen POI Collector is a handy way to collect POI data while out and about, or to edit existing data.


    Skobbler Navigation is also available for iPhone, again providing a full Tom-Tom style satnav for navigating on the go, all based on OpenStreetMap data.

    NavFree is another full satnav app based on OpenStreetMap data.

    Offmaps is an OSM map viewer that allows you to download large chunks of map tiles in advance so that you have them, for instance, when you go on holiday. I would recommend the original Offmaps over Offmaps2 as I believe the latter restricts the data you can access.

    Mapzen POI Collector again is available for iPhone and is a handy way to collect POI data while out and about, or to edit existing data.


    OpenStreetMap has been heavily involved in Humanitarian efforts, these have resulted in the formation of HOT - the Humanitarian OpenStreetMap Team. Projects have included mapping the Gaza Strip and Map Kibera a project to map the Kibera slum in Nairobi, Kenya. These projects have many benefits to the communities involved. Simply having map data helps the visibilities of important landmarks: water stations, Internet cafes, etc. Teaching the locals how to create the maps teaches valuable technical skills. Some people build on the data to provide commercial services to their neighbours, building businesses to support themselves and their families.

    A hugely influential demonstration of the impact of OpenStreetMap involvement in humanitarian efforts occurred after the massive earthquake that struck Haiti in 2010. Very shortly after the earthquake hit, the OSM community realised that the lack of geodata in what was essentially a third world country, would cause massive problems with aid workers going in to help after the earthquake. The community responded by tracing the aerial imagery that was already available to start to improve the data and later efforts included getting newer imagery, getting Haitian ex-pats to help with naming features and working with the aid agencies to add their data to the map. You can see some of the effects of these efforts from the video below that shows the edits that occurred in Haiti around the time of the earthquake.

    OpenStreetMap - Project Haiti from ItoWorld on Vimeo.


    If all of this has piqued your interest then visit openstreetmap.org to take a look at the map, sign up and get involved in editing. Find more information on the wiki at wiki.openstreetmap.org or find out how you can switch your website to OpenStreetMap at Switch2OSM.org

  • YAHMS: Revisited, Upgrading to XBee with Wire Antenna

    A good few months ago I blogged about my YAHMS project and my YAHMS Base Station. It was a funny time to get the project complete, just in time for the summer, but it has ended up being useful. Being able to turn the hall light on when we come home in the dark is really useful and, with the summer we’ve had, the heating has gone on from time to time too.

    It hasn’t been without its problems, though fortunately they have been relatively few. Power ended up being an issue for the temperature probes, using four AA batteries would keep the probes running for about a week. This isn’t bad but would mean replacing them regularly, also when the voltage went low, the voltage detector didn’t seem to work and I would see rising temperatures. In the end I decided to use some wall wart power supplies, unfortunately that means the probes are less portable and also means that half of the circuit was unnecessary, as the wall warts never provide a low voltage.

    I’ve also had problems with the Base Station falling off the network after around 5-7 days of use. There was originally a problem with the DHCP lease expiring so I made some changes to make it re-request the lease when it was near to expiring. This didn’t entirely fix the problem so to be sure I switched to a fixed IP. This led to the 5-7 day uptime, I’m not really sure what is happening here, I’m guessing some memory usage problem whereby there are not enough resources left to create a new Client object but I haven’t been able to track it down. When the problem occurs the system still manages to turn the heating on and off at the right times so it isn’t entirely useless, but it does become unresponsive to new settings and won’t send back data either.

    Final problem, and the one I’m going to fix today, is that the XBee modules sometimes have issues transmitting data to the base station. I originally wanted to have one upstairs but couldn’t get that to work at all. I ended up putting that one in the conservatory to get “outside” temperatures but it still has issues quite often and has to be positioned right by the door to even sometimes work.

    A few months ago I was approached by someone from Farnell who wanted to know if I would like to receive hardware to review on my blog. The arrangement is that they will send me hardware in exchange for a review on my blog and a link to the product on their website. So, here goes…

    XBee Wire Antenna Module (Series 1)

    Previously I’ve used the chip antenna versions of the XBee series one modules. These were great and really simple to work with but when I tried to use them in a network around my house I had real issues trying to get the signal to pass through walls and ceilings/floors. The best solution would likely be to replace all of the XBee modules with alternatives with better antennas or with more powerful radios. To replace all of the modules would be quite expensive so I’ve decided to go with replacing just the module on the base station and hope that it does a better job of receiving the signals sent out by the other modules. This may be foolish but I’ll give it a go and see what happens.

    To replace the module should be a pretty simple job, it’s the same format as the chip antenna module so physically I just have to switch it out for the new one. Before I can do that though requires that I send some settings to the XBee to configure its ID and PAN ID as mentioned in my post about the temperature probes. To communicate with the Xbee I’m just going to use an Arduino Uno and wire the Din/Dout pins on the XBee to the RX/TX pins on the Arduino. I then load a blank sketch onto the Arduino and use the Serial Monitor to communicate with the XBee. What I’ll be sending to it is:


    Which broken down means:

    • AT _ - Attention!_

    • MY=0, _ - the ID of this unit_

    • ID=1234, _ - the PAN ID for the network of XBees_

    To send those settings open your Arduino software, choose the right serial port in Tools -> Serial Port then open the serial monitor with Tools -> Serial Monitor. Choose to send no line endings from the drop down at the bottom and send +++ then as quick as you can manage change to Carriage Return in the drop down first and send the above AT command. After the +++ you should see OK and after the AT command you should see OKOK.

    You must also send an ATWR command too to write these settings to the flash memory.

    Once I did that I started seeing random bits of binary data appearing in the Serial Monitor. Fortunately this was a good thing, it was the temperature data from my probes starting to show up!

    I popped the newly configured module into my YAHMs hardware and waited to see if it worked…

    As mentioned it was already receiving data so I started to see temperatures show up straight away. The conservatory probe was working straight away which seemed positive as it had issues before. When I took it upstairs it didn’t seem to work at first so I tried angling the box so that the chip antenna would be “pointing” at the base station. This seemed to do the trick and I started collecting temperature readings. Unfortunately as time has gone by I’ve found that it works less and less. I’ve now moved it closer to the base station which got me a few more readings but again it has stopped working. It looks like I’m gonna need a bigger boat aerial!

    Hopefully I’m going to be able to try out an XBee with an external aerial which should work well on the base station, by this point I’ll have a few spare XBees, including one with a wire aerial so I should be able to get a much bigger range of readings.

  • Reversing the Brain Drain

    An unfortunate tweet from a friend yesterday suggesting that he might have to leave Liverpool to get a job, led to a little exchange:

    That got me to a realisation:

    Tweet text: "Recent tweet just made me realise that at @DoESLiverpool we've already recovered/rescued 4 people from working outside of Liverpool"

    Now that comment is certainly meant to be taken as tongue in cheek, but there’s some very real truth in it. To start with the more tenuous examples. Paul Freeman (@OddEssay) contracts for a company in Eccles, near Manchester. Since setting up DoES Liverpool Paul has been able to spend more time in Liverpool. Yes he’s still working for a company in Eccles but he’s now buying lunch from Liverpool companies and engaging with the Liverpool tech community more regularly.

    Let’s move onto Paul Kinlan (@Paul_Kinlan). Paul is a Developer Advocate with Google. He’s based in their London office but also spends a lot of his time travelling around Europe and the world promoting Google Chrome and HTML5. His main reason for being here is to work with developers who are using Google products in the north of England, but by supporting DoES Liverpool and taking a desk with us Paul is now able to spend more time in Liverpool meaning he gets to spend more time with his family who are still based up here.

    Finally we have Andy Hughes (@andyhughes86) and Andy Powell (@p0welly). They work for a company in Manchester who had offices in Stockport. Andy and Andy are both developers who worked in an office full of sales people. These were people who spent most of their time on the phone trying to make sales. Not the best environment for a pair of developers who need to get their head down and concentrate. Their company was moving into an office in Central Manchester, a smaller office in a trendier area which was going to mean Andy and Andy would either be in closer quarters with their noisier colleagues, or have to find somewhere else to work. Fortunately they came across DoES Liverpool and came in for their free hot desk day (bringing donuts!) They liked what they saw and took two permanent desks with us. Andy H lives in Runcorn, Andy P lives in New Brighton. Andy H unfortunately still has a long bus ride (but we’ll come back to that) while Andy P now has a 20 minute commute! As it turns out, Andy H is now moving to Liverpool. I had a chat with him recently and asked if he was planning to move to Liverpool before they joined us at DoES Liverpool. He told me that while he really wanted to move here he had resigned himself to living in Manchester. So not only do we have two people who are regularly coming to Liverpool and supporting businesses in the city centre, we’ve also got someone who would have had to live elsewhere being able to live in Liverpool as he’d hoped, paying taxes and again supporting local businesses.

    So this blog post certainly isn’t meant to suggest that other places are bad. Generally at the moment though if you want to work for a digital company in Liverpool your choices are to join a digital agency or go it alone. If you don’t want to do this you’ll probably need to work elsewhere. I also recognise that in all of the examples given the person is still working for a company based outside Liverpool. It’s nice though to recognise that even at this early stage DoES is supporting local people and even changing their lives for the better. Hopefully in the future as people start building new businesses based out of DoES those businesses will expand and will start recruiting more and more people from the city who will no longer have to leave just to find a good job.

    We also got some more news coverage recently, on Friday getting in the Daily Post for hosting the OpenLabs Developer Breakfast events, and an article 2 weeks ago that we only heard about because someone came into DoES for a look around, as a result of seeing it in the Metro. As it turns out that one was syndicated so we were mentioned all over the place!

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