Sending the Spark Core to the depths

Thought I’d come along and share a little project that I’m working on at the moment… It’s an entry I’ve put in, probably a bit too late, to “The BLUE : Ocean Conservation Fellowship Grant” which is coming to a close at the end of this month -

The aim is to build an open source / open hardware buoyancy controlling sensor platform - think along the lines of the Argo buoys (link at bottom), but smaller and, frankly, considerably cheaper.

A secondary aim is to have the platform able to ground itself for periods of time at the bottom and monitor various sensors (hydrophone, temperature, etc). If the sensor input comes within a certain range then the platform will surface and send a message - an example would be listening for engine noises in an area where there shouldn’t be boat traffic.

The technology is actually quite simple, you have a bladder and reservoir (syringes) which, driven by a continuous rotating servo and stop micro-switches, can alter the volume of the buoy (the mass staying the same, this alters the buoyancy) - coupled with a depth sensor you should be able to have a fair amount of control over it’s vertical location in the water column. Of course if the aim is to sit on the bottom then you just make it as negatively buoyant as possible until it needs to surface :smile:

With enough power, a GPS and a rockBLOCK iridium modem they could be placed anywhere and be able to send data back.

I decided to use the Spark Core rather than a small arduino because the integrated wifi and cloud is just so damn useful - it means that I can update and communicate with the device (when within range) without removing it from the pressure container and risk getting the electronics wet - it also means that I can make small, demo, versions that can be controlled via Twitter for taking to schools - I’m planning to be at the Big Bang Fair 2015 in Birmingham, UK with a few of them for attending children to play with.

I made a cool little video (at the link above) explaining the operation - I don’t think I can embed it here (or at least I don’t know how to).

Anyway, thanks for your time reading - I’ll post some updates as the construction progresses and I get out and test the functionality and depth capability :smile:


So cool! Here’s the video embedded:

Looks very cool. One point - I don’t believe the Spark Core will let you communicate with other Spark Cores if that is what you were intending?

@Rockvole Do you mean peer-to-peer communication? Because you can use the Spark cloud and publish/subscribe to handle core to core communication.

Yes thats what I meant. I didnt realise you would have your own cloud setup out there :smile:

In the field (sea) I think they’ll initially be reliant on the Iridium modem for sending data back - for communications on / with the boat I’m going to see what I can do with a local wifi connection (of some sort) and a local version of the spark cloud (haven’t tried this part, but it’ll be fun seeing what can be done).

Long term it would be good / interesting if they could talk to a base-station either on land, or a surface buoy of some sort providing the local cloud network and sending data on via Iridium, as that would save the costs of the modem in each unit (which is a huge chunk of the cost).

I’m delighted to announce that the Spark core powered Bob project was awarded the “The BLUE : Ocean Conservation Fellowship Grant” -

Still a little bit speechless here - so more information on the development and communication plans coming soon.


I’ve realised that I haven’t updated this thread for a while - we took four Spark Core powered Bobs to the Big Bang Fair at the NEC last week - there are more details (and some information on the building process here - ).

As we progress on the build of mk2 I’ll see if I can keep both locations updated.