Bluetooth Enabled… London Bridge

[Mike] sent in a different sort of hack – as part of the switched on London festival, these guys added bluetooth sensors to London Bridge. When a bluetooth enabled device is detected on the bridge, a blue ‘pixel’ will show up on the upper tower bridge. Once the device is detected at the other side of the bridge, the ‘pixel’ will move across the bridge at the same speed as the device did. You’ve got a few more days to check it out if you’re in the area.

Update: Just to be clear – the sensors are on the new London bridge, and the pixel/light appears along the top of Tower bridge. Sorry for the confustion, I haven’t been in London since 1995 or so. I mistakenly assumed that the lights were on the upper tower of the bridge.

27 thoughts on “Bluetooth Enabled… London Bridge

  1. They should get a few more sensors, so it can get closer to real time…. eg: small segments rather than 1 big display… but without fixing the 20 second lag, this would be useless anyways.

    Sounds like a lot of fun. I could think of a couple of fun places to put things like these… :D

    I don’t see any actual technical details anywhere though!

  2. Oops, looks like the link you had was describing tower bridge. the festival page has one for london bridge. the two bridges apparently mark either end of the lighting festival. my bad.

  3. This is quite possibly the most stupid thing I have seen on Hackaday…..WTF!?? I realize that valentines day is a slow day, but COME ON!! Am I the only reader who feels this way? I mean…..its a bridge….they added some blue lights and a couple of bluetooth sensors….so what? No diagrams….No EXPLAINATIONS of how it was done….just “..youve got a few more days to check it out if youre in the area”

    Gee, thanks! I will have to rush right out to LONDON and check that out!!!!


  4. i think that this raises [unintentionally] an interesting point about announcing the presence of electronic devices in public places. as solid, feature-rich smartphones and handhelds [as well as media players with broadcasting abilities such as the zune.] become more affordable and more accessible to the mainstream, should we [the ‘universal we’, if you will.] place any focus on trying to encourage that guy at starbucks to chat with that girl ordering a chai latte through a digital medium?

    i guess a few blue lights on a bridge in london doesn’t raise a question like that, but, this very project was discussed at school today in a technology ethics class, and some in the class argued in favor of installing such devices in common places with alot of traffic [libraries, college campus centers, starbucks, etc.] so that one would know how many other device users are in the area, and whether or not they might have files, information, and media to share.

    especially as software like ‘dodgeball’ [which i guess is still owned by google, though it isnt being promoted as thoroughly as most of their projects?] might gain popularity among new age community developers who see that technology might be the next frontier for being a ‘good neighbor’. [since studies have shown again and again that we are losing social capital due to the ease of electronic communication.]

    just some food for thought i guess?

  5. I walk over Tower Bridge twice a day (sometimes London Bridge instead) and around the Pool of London area.

    What I have seen from the Switched on London website in no way seems to reflect the reality of what has been done in this area.

    The proposal web page for the bluetooth lighting does not mention Tower Bridge at all, and there are no lighting installations that I can see there, so I think that London Bridge must be where it was intended for. However, I have seen no moving lights on London Bridge yet, although some months ago red lights were added to edges, probably unrelated to this project. Blue strip lights where recently added to the railings around the scoop, but again it seems unrelated to this.

    The artwork of the Belfast is not reflected in reality, there are no large beams coming from the guns, although there are new lights there which illuminate the underside of the guns and flicker oddly, looking much like malfunctioning fluorescent tubes.

    The other pages (not including those marked with ‘concept’) are equally not reality – unless they only have it on at weekends, which would kind of defeat their statement of 8-16th for the festival dates. City Hall and Hays Wharf do not look like their pages, and I’ve seen no hanging red lights on the south walkway yet. (I’ve not seen the Design Museum, but I may have a look tonight).

    The only exception is the Tower of London page 2 – it does actually look like the top photo. The rest appears to be vapour.

    I bet you all the money got spent though.

  6. The article clearly states (as someone already mentioned, but people are still pointing out the ‘incorrect’ bridge name) that the sensors are on London Bridge, and the lights are on Tower Bridege.

    “Bluetooth devices detected towards each end of London Bridge will appear as coloured pixels on the
    corresponding end of the Tower Bridge upper walkway”

  7. this would be neat to install on a wall next to a sidewalk… as someone with a bluetooth phone walks by a lighted arrow points at their phone until they exit the area… that would be fun but annoying…

  8. Just to clear up a few things (I did the custom electronics and software for this project).
    This is the first year of this event and it was done on a near-zero budget to get something happenning in the hope of making it a more regular event with some proper funding next time. Many of the projects on the SOL website did not happen for a whole number of reasons but unfortunately they didn’t update the site, which gave a slightly misleading impression. Some things got changed/cancelled at a very late stage – we were all set to install on London bridge and then found out the access cradle was not useable. The decision to change to Tower Bridge happenned about a week before we had to start the install,and even after that it was off & then on again once DURING the install…. In fact the Tower Bridge setup works better than a London Bridge one would have as people on London bridge can see the effect themselves.
    Since the start we have had a few power supply problems, but the only night we were completely dead was Sunday & we have had one of the 2 sections missing on 2 other nights.
    We would certainly have liked to have had more sensors – ideally 2 at each end to get a speed and direction by the time people reach the ‘first’ end of the bridge so the speed accross the bridge can be matched better. Time, budget and availability of the RF modems simply did not allow this. All the sensor hardware & software, and the controller hardware & software was designed and built from scratch in about 2 weeks.
    One major issue in using Bluetooth in this way is that you are stuck with an update rate of the order of 10 seconds due to the randomising of the response time from the detected devices. Range is also somewhat variable, so on a relatively short span like this it is not practical to get especially accurate speed data. However at less busy times it is easy to get see a very obvious response to individual bluetooth devices as you move along the bridge.
    One approach I am plannning to investigate is the use of multiple bluetooth modules doing staggered, overlapping scans, as well as using RSSI data.
    One good thing that has come out of this is a load of data we can sit down and look at to see what might be achievable with more time, and a budget.

    I will be adding some stuff to my site, hopefully including some video, as the dynamics are what really make it work.

    Regarding the ‘hackiness’, there are a couple of things not yet on my site that fall into that catagory – firstly we programmed in a number of ‘magic’ MACs for the phones of some of the people involved in the project, so they get their own special display. Also I have a ‘test’ trasmitter that lets me make it do all sorts of wizzy stuff from anywhere that is within view – this is particularly good for freaking out tourists when you
    go up next to them, pull out what looks like a big TV remote and start making things happen on the bridge….
    We will be doing a presentation at dorkbotlondon on this in the near future – possibly March

  9. Hackiness?? HACKINESS!?!?!

    Okay look….if you take a toaster and meld it together with a skateboard, THAT is a hack! IF you take a computer and combine it with a set of hot rollers…THAT IS ALSO A HACK!! but there is NOTHING~~~I REPEAT….NOTHING even remotely “Hacki” about installing lights on a bridge….even if blue tooth turns em on….HOW does the bluetooth turn them on?????

    WE HAVE NO IDEA!!!!!! WHY????


    My little sister stuck a toothbrush up her dolls butt….THAT was more of a hack than this!!!!

    I am SOOOO very disappointed that this “HACKI” BS made it onto this site……I dont care what you post in the future because I AM SO DISAPPOINTED IN HACKADAY for calling this a hack I SIMPLY WONT BE JOINING YOU PEOPLE ANYMORE….

    Ohhhhh!! Somebody put lights on a bridge?!?! LET ME SEE!!!!

    gimme a break. this is STUPID!!!!!

    I repeat…..


  10. Technically, they hacked a bridge with computers, bluetooth recievers and dmx hardware, not to mention lots of L.E.D’s. So stop being so critical, I would count this as a hack. Mike also said that he had not put the ‘hackiness’ related stuff on his site yet…mr jones, maybe you should read a comment through first to aviod making yourself look stupid, but then if you come from a family where your sister sticks a toothbrush up a dolls arse its given..

  11. One man’s Stupid is another’s hack.
    Bridges are not designed to be used as people-flow displays. Bluetooth is not designed to be used to measure traffic flow. Nobody makes a wireless bluetooth relay so one had to be built from scratch.
    And if you have ever done a project on this scale in such a stupidly short timescale you would realise that there is not the time and energy to fully document every detail immediately afterwards. I don’t even HAVE schematics as I did the PCBs from my head. The detailed schematics are not important anyway as it is mostly made from off-the-shelf modules that any half-competent hacker ought to be able to figure out to do in their own way.
    My site does however include a detailed description of exactly how the behaviour is controlled by BT devices, such that anyone who wants to can go there and see it work for themselves.
    So whilst some may be happily entertained by doll-rectal toothbrush activities, others might like the opportunity to go play with a famous landmark with some inside knowledge of how it works and how they can control its behaviour.

  12. OK well I went and checked it out last night.

    I took photos of the various installations (those that I could find).

    They are in a flickr set with descriptions here:

    I actually like the bluetooth hack idea.

    But the rest of the projects I think are pretty poor. There was no effort that I could see to promote it. The official site has not been updated to show which displays actually happened so that you can go look at them. There is also no promotion in the area, a few posters explaining what was happening would have been nice for people who are visiting the area anyway.

  13. I’d say this meets at least several of these requirements. They had a short timespan, they did the best they could with what they had, and made it work, even if not as best they could have, with a proper budget, materials, and time.

    Ergo, this was a hack.

    And personally, I’m a sucker for lights that you can make do things… I wish I had that remote! ^_^ (and unless you can do something bigger, or better, please, shut up, think, think again, then three more times, go walk the dog – if you don’t have one, find one – and THEN come back and post. Then you won’t look like some of the 2nd graders at the school I teach at.)

    From The Free On-line Dictionary of Computing (27 SEP 03) :


    1. Originally, a quick job that produces what is
    needed, but not well.

    2. An incredibly good, and perhaps very time-consuming, piece
    of work that produces exactly what is needed.

    3. To bear emotionally or physically. “I can’t hack this

    4. To work on something (typically a program). In an
    immediate sense: “What are you doing?” “I’m hacking TECO.”
    In a general (time-extended) sense: “What do you do around
    here?” “I hack TECO.” More generally, “I hack “foo”” is
    roughly equivalent to “”foo” is my major interest (or
    project)”. “I hack solid-state physics.” See Hacking X for

    5. To pull a prank on. See hacker.

    6. To interact with a computer in a playful and exploratory
    rather than goal-directed way. “Whatcha up to?” “Oh, just

    7. Short for hacker.

    8. See nethack.

    9. (MIT) To explore the basements, roof ledges, and steam
    tunnels of a large, institutional building, to the dismay of
    Physical Plant workers and (since this is usually performed at
    educational institutions) the Campus Police. This activity
    has been found to be eerily similar to playing adventure games
    such as Dungeons and Dragons and Zork. See also

  14. I think mike should recieve everyones kudos for this hack. It is by no- means a small scale project. Maybe people who probably havnt visited the bridge, and claim that this isn’t a hack worthy of hack a day should just STFU!! The hack is obviously a huge job, i mean i work as a lighting technician in a theatre and I couldn’t even begin to think about the logistics of getting a line of ‘chroma bar’ style led batons along the top of the tower bridge, let alone program the bluetooth to dmx conversion side of things. As with comment #22 I also believe that if you can’t do better yourself don’t bad mouth it…it just makes you look like a tosser…

  15. We’re planning to do a presentation on this project for dorkbot london ( in March (date tbc) which will include all the gory technical and logistical details. We’ve asked the lighting supplier if we can keep some of the lights until then so we can have a subset of the bridge setup running live.
    Re. #21 – we did seriously think about the possibility of our sensor boxes cable-tied to lampposts being mistaken for something sinister, but as far as we know no serious security scares ensued… We did have them put there by the City’s lighting contractor to avoid getting arrested….

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