What is It

How often have you sent off a message in a bottle, only to realise, as it floats out of sight, that you regret the contents of your message? Well, with the Text Message in a Bottle (TM) that will no longer be a problem! You can update your message at any time, just by sending a text. Fantastic!

Why Did I Build It

I have been following the oodles of submissions to the LinkIt One MediaTek Collection, and most of them are without housings, even projects like weather stations that are ostensibly for use outdoors, so I decided to demonstrate a simple waterproof project with off the (kitchen) shelf parts.

Features (or, what you can learn in this Instructable)

  • Battery Powered
  • Solar Charged
  • Display battery/charging status on one line of a 16x2 character LCD
  • Receives SMS
  • Display scrolling SMS on the other line of a 16x2 character LCD

Other Ideas/Complications

My original plan was to make a completely self-contained, solar-powered, WiFi-hotspot-in-a-jar, that would allow people to connect and download files or leave notes on a web server or something, but unfortunately the LinkIt One does not support running the WiFi in Access Point (AP) mode.

My next idea was to the same sort of thing using Bluetooth, like some shops do, where they send you an image or message when you come in range (proximity marketing), but it seems that this is also not yet in the API.

Step 1: Components Used

Linkit One

The MediaTek LinkIt One is an Arduino-compatible board with some very cool features built in, in this project we are using the built-in GSM for receiving SMS messages as well as the built-in battery charger to charge the included battery.

Sim Card

A prepaid sim-card that can receive text messages. Preferably one without a PIN.

Solar Panels

I used 3 long narrow 8-10V solar panels of approximately 1W output, I got them out of broken/obsolete equipment, so I don't have any info at all on them.

You should be able to buy things like this easily on sites such as Aliexpress if you don't mind waiting for the shipping.

DC-DC Converter/Regulator

I chose the Power Trends PT78ST105S because I had one lying around, here are its specs

Input Voltage: 9-38V

Output Voltage: 5V

Output Current: 1.5A

Duct Tape

I used a knock-off of Duct Tape to turn the three solar panels into a foldable unit, as well as to attach the various modules to the back of the panels. It looks like a hack job when open, but when folded up it is rather neat.


Jars designed for pickling or jams are ideal, because they have wide necks. I couldn't find a large enough Mason Jar, which i think would be the best, so I chose a 1.5l swing top instead.

<p>Muito boa a id&eacute;ia, parab&eacute;ns !!!!!</p>
<p>ossum, very technical indeed. I have a few questions about your instructable. What is or is there a range to the bottle before it can not get a signal to send a text message? For the shaded side of the solar panel while in the bottle, could a small piece of mirror help reflect the sun light to the shaded area? Will the sun damage the LCD screen if its faced up? Will there be any condensation built up in the bottle which could damage the circuit board? Would like to know if these were some of the questions you asked yourself when coming up with this project. This is thinking outside of the box an could be used in different environments. Good luck in the contest.</p>
<p>Thanks for the questions! As I'm sure you guessed, this wasn't really for sending out to sea, but more a way to demonstrate a completely sealed, self-powered device, so range was not a huge concern. Nevertheless, on land the range would be as good as any cellphone, but in the water it would be reduced (water attenuates RF waves heavily).</p><p>The mirror idea is interesting. My gut feeling is that it would be hard to orientate it in a way that provided significant gain when the panel wasn't lit, without blocking that same panel when it would normally be getting full sun. Off the top of my head, if i wanted keep all panels lit I wold arrange them all &quot;upwards&quot; on a pivot (like an axle running from the top to the bottom of the jar), with all of the weight at the bottom, so that they stayed that way no matter which side the jar lay on. Or one could get really high tech and <a href="https://www.instructables.com/id/Solar-Power-the-LinkIt-One-With-Tracking/">track the sun</a>.</p><p>The next two are very good questions, and not ones I had thought about before. Condensation could be easily handled by a bit of silica gel in the bottle, but the LCD damage from UV would be harder to deal with, I guess an E-ink display would be better, it's nice and low power too.</p><p>Thanks for making me think :-D It's fun to ponder applications and solutions for projects like this.</p>
Good suggestions to my questions. For condensation you could use some rice in a piece of woman's stocking shoved to the bottom and that would take up the moister. If the panels were on three sides and the forth the LCD weighted down that would keep panels facing up and LCD out of the UV light. Still a good idea for emergencies or for fun.
<p>Truly a crazy inspired project. Thanks for the great detail!</p>
<p>I think you will find that most of my projects have a touch of crazy, but inspired is less common ;-) Thanks for the compliment!</p>
Now i know why cargo ships sinks in the ocean. Crashing into piles of littered mason jars.
On the upside, the survivors would be able to able to get messages...<br><br>Don't worry though, I didn't actually let one loose in the sea.
<p>This is one of the greatest ways i've seen to throw my money into the ocean! besides buying a yacht</p>
<p>I think this is one of the coolest ideas I have seen yet. a mini keyboard would have been cool as well. they could message back. Either way I love the idea</p>
<p>Thanks a lot! I agree some kind of input would be good for any kind of &quot;project in a bottle&quot;, the trick would be in sealing it I guess. My one thought was to use an infrared sensor that could detect movement through the glass as a kind of non-contact button.</p>
<p>Check out the cap touch sensor demos from the Microchip PIC library. You can make touch sensor buttons that work through the glass bottle. I even tried it with 1 inch thick paper.</p><p>Well I had asked the salesman at the microchip booth how thick it would work through and he didn't know. I just started piling up his brochures over the demo board until the RGB slider stopped responding.</p><p>Answered my question and gave the people around me something to laugh about......</p><p>*\</p>
<p>Capacitive sensor range can go pretty far, heavily depends on the material and the shape of the sensor.</p>
thanks, I'll check those out!
<p>or maybe bluetooth with a app the can download to communicate with it</p>
the only thing that put me off bluetooth was the requirement for an app on the phone (that's why i wanted to serve up a web page via WiFi, it would be perfect to leave dangling from a tree in a public place, just presenting a unsecured access point), but i agree, if the people using it knew what to download then a BT app would be perfect.
<p>This is amazing! It reminds me a little of my <a href="https://www.instructables.com/id/Digital-Message-in-a-Bottle/" target="_blank">Digital Message in a Bottle</a>.</p>
Just checked it out, now I imagine a combo of the two ideas, a bottle at the bottom of the sea, that charges up via solar power when it is brought to the surface and plays a message.
<p>Now that's a great idea! </p>
lol, thanks
<p>Interesting, I think I can make it even smaller with an OLED display. </p><p>Voted ! :)</p>
or an LED with morse code ;-) but it is the solar panelling that really takes up the space.
<p>Great use of a Mason jar. Had to vote for this too.....</p>
<p>This is very cool! I think that scientist could find this useful. I mean those guys that measure the flow speed of rivers etc. Or those which investigated the &quot;lost rubber ducks&quot; in oceans.</p>
<p>That is quite a cool idea. I couldn't think of any practical application for this as it stands, since I wasn't keen on losing it at sea ;-) The nice thing with the LinkIt One is that it has GPS on board too, in fact in my last Instructable I used it to report its location via SMS, so it would be easy to implement.</p>
Genius idea
<p>Thank you :-)</p>

About This Instructable




Bio: Electrical Engineer by trade, tinkerer by heart.
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