Scientists discover a way to send low energy and long range wireless signals!

Whenever your phone rings or you get a text message, radio waves carry that information, whether in the form of a voice or letters, across vast distances. Different forms of wireless communication use different types of radio waves, which are differentiated by their wavelength and frequency. Cellphone radio waves can travel far, but eventually they lose energy. To make sure that you get that very important text message, cellphone service providers amplify the signal with radio towers. But, some radio waves can travel even farther, like “very low frequency”, or VLF radio signals can travel miles, through air, land, and even water! This method of sending wireless signals is a great way for aircraft and submarines to navigate and communicate.

The catch with these low frequency signals is that creating an energy-efficient signal requires an extremely large antenna, often more than a kilometer long! This requirement limits the uses and practicality of these low frequency signals.

That is all about to change (insert obligatory dun dun dunnnnnn!!!):

Mark Kemp of of the Standard Linear Accelerator (SLAC) and his collaborators have been trying to build a low-energy and long-range radio antenna. In other words, they are trying to have it all.

Kemp and collaborators successfully built a long-range antenna prototype (pictured right) by using a creative approach: rather than using metal as is traditional for antennas, this collaboration used a material that expands and contracts to generate a radio wave. This allows a much smaller antenna that is able to be portable and long range!

We are excited for the possibilities of improved low-energy and long-range communication, particularly in remote areas, as it improves connectivity, safety, and access to services.

To learn more, you can read a more detailed summary of the prototype here: https://physicstoday.scitation.org/do/10.1063/PT.6.1.20190530a/full/

Or read the original published paper in the journal Nature: https://www.nature.com/articles/s41467-019-09680-2

Micro:Bit Puppet “Text Message” System

Intro

Nearly all of our wireless communication is done using radio waves*, including phone calls, text messages, and WiFi. With its built-in radio transmitters and receivers, the Micro:Bit microcontroller makes it super easy to build all sorts of projects with radio communication.

This particular project is a simple & quick way to send text messages between two Micro:Bit** microcontrollers – the sender writes a (short) message that is transmitted via radio to the receiving Micro:Bit, which shakes a lil’ puppet using a servo motor, and then displays the message on the Micro:Bit LED screen. Each Micro:Bit can be both a sender and receiver.

It’s sort of like a two-person Twitter.. if the tweet notified you via dancing cardboard robot puppet!

*Radio waves are long-wavelength light waves. Check out the electromagnetic spectrum here!

**A huge THANK YOU to Adafruit for donating the Micro:Bit microcontrollers used in this project for educational purposes! yayy thank you for supporting this educational endeavor!! 😀

Materials & Tools

Electronics

Puppet (or other Message Alert System) Materials

Tools

  • Hot Glue Gun
  • Scissors and/or utility knife (e.g. exacto knife)
  • Pencil
  • Ruler or other straightedge

Build the Incoming Message Alert Puppet!

Step 1: Build a cardboard puppet like the one shown in the photo or create your own! Use the paper fasteners to make joints.

Step 2: Build a mounting system to attach the puppet to the servo with skewers and cardboard.

I used a magnet to attach the puppet to the servo mounting system because magnets are awesome, but you can also use glue, tape, velcro, or a variety of other adhesives!

Step 3: Build a stand for the puppet.

  • On an approx. 6 in. x 12 in. cardboard sheet, measure, mark, and cut a hole for the servo body so that the arms of the servo rest against the front of the cardboard sheet.
  • Cut two triangles out of cardboard and glue them on the back of the stand so that the stand, well, stands upright!
  • Cut a hole for the Micro:Bit wires to thread through and add two pushpins on the front to hold the Micro:Bit.

 

 

 

 

 

 

 

Code the Two Micro:Bits!

To start, choose one Micro:Bit to be the sender and the other Micro:Bit to be the receiver. Once both are working as expected, add in the code for both roles.

Use the Make Code Micro:Bit website to program each Micro:Bit. As this is intended as a beginner project, the whole system can be built using the block-based programming language, although adaptations are encouraged and appreciated!

If there is more than one pair of Micro:Bits in the room (i.e. in a classroom setting), remember to set different radio group numbers for each pair.

The sender sends a (short) text based on user inputs over radio, like the example above. Pretty simple!

The receiver moves the servo when an incoming text is received, then scrolls the message text on the LED screen, like in the example below.

Press the reset button to stop sending/receiving the incoming message.

 

Connect the Servo!

Connect the servo red wire to the Micro:Bit 3V power pin, the servo black wire to Micro:Bit ground pin, and the servo white (or yellow) wire to the Micro:Bit input pin P0.

Send all the Messages!

Program both Micro:Bits to be both a sender and a receiver so you can communicate back and forth. Then switch power from the laptop to the battery pack and test out your wireless communication system! When the sender sends a message, the puppet will notify you to check the LED screen so that you can see the incoming message.

How far of a range can you get? Test it out!

There are tons of other extensions to this introductory project, here are some possibilities:

  • Add more message options by adding more inputs or changing how those inputs are read;
  • Instead of a table-top alert system, build a wearable alert system;
  • Send voice messages and/or other sounds.

Happy building!