Android Ocean Drifter




Introduction: Android Ocean Drifter

About: Education: - Sailing robots: Protei Inc & Scoutbots CEO Personal:

The ocean covers more than 70% of our planet, yet it's estimated we've explored only about 5% of it. Maybe because studying the ocean can be quite time-consuming and / or expensive.

Recently, with WWF and MakerBay in Hong Kong, we built an Open Hardware fleet of ocean drifters operating on the 3G network, to map river, estuary and coastal pollution (as far as the mobile network allowed us to - so not the deep ocean). The project name is "Marine Litter Detective" and you can see our 110 drifters on this Leaflet map + timeline . We used the Seeed Studio "LoNet 808 - Mini GSM&GPRS + GPS Breakout" board and we deployed our drifters in Hong Kong drains, rivers and ocean, working with 11 local schools. Some of our low-cost drifters went as far as Taiwan (about 1000 km in 1 month). When we say low-cost, each device material cost is under 500 HKD all inclusive (under 60 USD / 55 EUR) with a custom PCB from Seeed Studio. We had a lot of press for this pilot project (below) and request to make the technology simpler so more people could get involved. This is what this instructable is about: making a simpler version with something many people can get their hands on, an Android Phone. Of course, an Android Device is not as energy efficient and this instructable is a simple hack, so please tell us how we could make it more energy efficient and run for a longer time. For example, making a custom ROM and / or app for the phone would make a lot of sense, or adding an extra battery and a solar panel - yes!

Our ultimate goal is to understand marine pollution to reduce the negative impact of humans on the ocean, so you can imagine we are doing our best to reduce the pollution our sensors themselves constitute. for the previous version, we do this in different ways:

  1. Smaller footprint: We shrink from a full-size arduino to a Arduino pro mini
  2. Replace the plastic casing: we experimented with biodegradable materials such as coconut, wax and cork
  3. Replace PCBs: with paper electronics, inspired by the work of Jie Qi
  4. Optimize software for expanded autonomy
  5. Remove unnecessary power sink such as LEDs on the Arduino board
  6. Reduce batteries: number, size, and capacity of battery, going from 2 to 1 and expanding autonomy.

In this instructable, we will show you how to hack a regular Android phone to make a temporary low-cost Ocean Drifter for your next science project. So NOT what the images in this step show (that is on github here), but a simpler version that requires next to zero coding and electronics knowledge. And by the way, we haven't tried this for a long time in the open waters, so we do not guarantee success of this device

This Android Ocean Drifter has been taught in these workshops during Hong Kong 1st Citizen Science Faire:

Thanks to the original team for the Marine Litter Detective Team

Patrick Yeung [WWF], Cesar Jung-Harada [MakerBay] Eddie Yung [MakerBay], Rohak Singhal [MakerBay], Wong Ching Sun [MakerBay], CY CHENG. Special thanks to Seeed Studio, James Manning (NOAA), Xavier Huanxin Xu (NOAA), Tom Chi, Jie Qi (MIT), Cy Keener (Stanford University).


1. 全球定位「臥底」追蹤海洋垃圾 環團實測:香港垃圾最遠漂至台灣 [HK01] 2017-08-14 (08:05) 最新文章 潘希橋

2. GPS追蹤器模擬海洋垃圾47 日抵台北 環團科研社企合作冀助了解垃圾去向 [Ming Pao Daily News] 2017-08-14 A03 港聞

3. 以蠟製造可自然分解 [Ming Pao Daily News] 2017-08-14 A03 港聞

4. 調查:四成渠口垃圾不被阻隔排至河流和海洋 [Now Local News] 2017-08-14

5. 定位儀器放渠道 記錄水流路線 GPS大追蹤 港海洋垃圾可漂至台北 [Apple Daily] 2017-08-14 A08 港聞

6. 裝置電路板無法分解 基金會籲拾獲交回 [Apple Daily] 2017-08-14 A08 港聞

7. 海洋垃圾邊到來?竟然同雨水渠有關? [] 2017-08-14:

8. Stop urban litter becoming marine waste: WWF-HK (00:13) [RTHK News (English)] 2017-08-14 Local

9. 海上GPS追蹤港垃圾 最遠漂台北 [Sing Tao Daily] 2017-08-14 A10 港聞

10. Tracking litter trail all the way to Taiwan [South China Morning Post] 2017-08-14 CITY1 CITY Environment Xinqi Su

11. DIGEST: HK litter tracked to Taiwan [South China Morning Post] 2017-08-14 EDT1 EDT:

12. GPS追蹤海洋垃圾 [RTHK News] 2017-08-14 晨早新聞天地 Start from 55:25

Step 1: Factory Reset Your Android Device

There are many flavors of Android and my recommendation would look for the right combination of keys or action in the system to Factory Reset your Android. Save all of your precious data and now you can go in your System / Privacy / Factory Reset for my phone.

Step 2: Set Up a New Google Account

Setting a new Google account is simple and free. If you have multiple devices, I recommend to name them in a serial way, so they are easy to organize in your database later. Link to signup.

Step 3: Manage Your Battery to Maximize Autonomy

There are many good app to make sure your device survives long enough for you to retrieve it from the ocean.
The less apps are running, the better. This app seems to do a decent job, "Power Pro Battery Saver":

Step 4: "Share My Location" on Google Maps

If you intend to run a fleet, you will need to do that on every single device. You can have one "MASTER" device that sees all, or you can work in a decentralised way (smarter) where every device can see the other devices - which makes this Google share my location as good as your 3G network gets.

There are other "fleet management" apps out there too on I will focus hacking regular Android Phone.

But have a look at this too:

Step 5: Waterproof Your Phone!

Once your phone is ready to launch, you need to make sure it's going to be ok with water.

We recommend these methods:

PVC toilet pipes
It works very well, it's cheap, by the ocean does not love PVC. That's what we did originally, we're still trying to make something better.

O-ring equipped glass canister
Glass is clean but it breaks easily... If you release in the middle of the ocean, that is not a big deal. But if you release in busy waters or in the drain, that could be a problem and a hazard...

Pelican Case
Pelican cases are used a lot by the US military. Many of them are waterproof and very resilient to impact. But also not super eco...

Wax + Cotton
This is our new favorite method. It has been working well but you have to make sure it is truly watertight. We have also been mixing wax with cork in powder form, to make our material is better at floating, impact-insulating. What we do is that we wrap or device inside a thin film of paper, and we dip our device is melted wax, many times, attached to a thin thread of cotton.

The video shows what we are doing with another generation of device, you would do the same with your phone.

Step 6: Start Collecting Devices Locations!

And now it is time for you to get out and throw your device in the water!
In Hong Kong we have a great tide prediction system:
Choose your launch point wisely as it will inform you where you should be launching your recovery operation (further step) later.

Step 7: Export Individual KML Files

At this stage you should be able to see multiple of your devices moving on the map. Great.
This step is about collecting the data.
This is the link to collect the KML file from your data (Google Location History):

What is a KML File?
"KML is a file format used to display geographic data in an Earth browser such as Google Earth. KML uses a tag-based structure with nested elements and attributes and is based on the XML standard. All tags are case-sensitive and must appear exactly as they are listed in the KML Reference. The Reference indicates which tags are optional. Within a given element, tags must appear in the order shown in the Reference."

Step 8: Aggregate KML Files to One Google Earth File

Once you got the KML file on your laptop, you can open it using any text editor.

If you use mac, we recommend the free text editor Atom by GitHub.

If you end up with a lot of .kml files from your fleet of drifters, this is the coding free workaround:

"kmz is a zipped archive of kml or kmls.
You could try this: Create a folder Drag all the kml files into the folder Zip the folder, the file extension will be ".zip" Rename "zip" to "kmz"
kmz will open in kml friendly programs, like Google Earth and My Maps
If you then wanted the one file to be kml, you could open the kmz file in Google Earth. It should open as a folder with the kml files as sub folders/content. You could then right click on the main folder and select "Save AS-->kml"!topic/maps/TIRfEkSgIwM

Step 9: Optional: Collect Other Data Such As Temperature, Atmospheric Pressure, Wave Intensity

Now if you want to go further and collect more than just the location of your fleet of devices, you could be using a lot of the sensors on your phone. Modern smartphones tend to be jammed packed with sensors - take advantage of there like the folks of 1Sheeld:

1. Test your device
I would recommend first to test your device sensors. On Samsung, the video shows how to do it - using secret codes (video above)

2. GPS Log
Get a very nice GPS log with altitude, speed (with colors) and more with OpenGPS Tracker: data:

3. Wave Log
You can record the intensity of waves with Google Science Journal, it's awesome:

4. Barometric Log
You can record the atmospheric pressure (if you can manage to expose your sensor while remaining watertight):

5. Sensor log
There are many options out there, I haven't tried this one, but it looks promising: Sensor Multitool:

6. More sensors!
We are very interested in DFrobot KnowFlow for that it aims at measuring pH, Temperature, Dissolved Oxygen, Electronic Conductivity, ORP... AWESOME!

Step 10: Retrieve the Device, Spare the Ocean

We assume that you had a good estimate of your phone battery autonomy. So BEFORE YOU LOOSE SIGNAL (because of battery or distance) you now have a great excuse to get on the water and go collect your devices!
You do this because you love the ocean, and you also probably love your phone, and your SIM Card with that sweet data plan right? Enjoy your sailing and clean up the ocean :)

Image credit:

Step 11: Share and Analyze Your Data

To share your data we recommend different ways:

1. Google MyMaps
Simply Create a new map / Import or upload your kml / kmz, ta-daaaa!
One of the beauties of Google MyMaps is that you can also edit the data within a visual interface and move single points on the base map. Very handy if you have GPS anomalies! You can than re-export the newly edited KML file after you've cleaned it like a pro. What's really good is that once you made your map, you can easily share it with a lin or embed it as an interactive map online.

2. Google FusionTables
Google Fusion Tables can transform any CSV into a gracious map. Kml files are essentially CSV files, so it's a great tool to extract some data out of your KML file.

3. Go from .kml to .gpx and more
There are many geographic format out there that can help you get more out of your data. has many formats that you you can convert your kml into. Tools like ,,, can convert your GPX file and give you many interesting stats. Useful.

4. GIS Packages
If you want to get serious about this, we highly recomend you to dive in the fascinating world of GIS, with QGIS for example :)

5. Real-time asset tracking
If you want to get super serious, you could even map this sweet fleet with

Thank you for your attention.
Save the ocean!

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    5 years ago

    The idea of cleaning up the ocean surface is very appealing!
    This will be even more wonderful when people go and collect every floating piece around their electronics spread into the oceans.

    Go for it! Spend some fuel and time and round them up along with a bunch of garbage. It'll make a tiny little dent in the problem but will alleviate it to some small degree.

    Maybe nets for massive collection?

    On the other hand, a small sail and rudder with a solar cell to give power to manage the direction of drift would allow these to "return home" to some extent and prevent them from adding to the total amount of flotsam. Once back near shore, these devices would be easier to retrieve.


    5 years ago

    What an excellent concept. I live well inland in Canada and I can see it used in the inland great lakes system. I wish I was young enough to get involved in this kind of venture, but I'm sure your instructable will do a lot to inspire younger people to form groups or clubs and get involved. Only good can come from collecting this kind of data & knowledge!


    5 years ago

    Very cool!


    5 years ago

    Par excellence


    5 years ago

    Great imagination and execution! Thanks for sharing