You can do almost anything with the right combination of Feather microcontroller and FeatherWing! From blasting on a fan to opening a trap door, from making a playing card levitate to lighting up hundreds of NeoPixels, from cuing music and sound effects to detonating a smoke bomb, it's all possible.

But what about triggering these events remotely at long distances, in a cell-phone (and human) dense environment, such as a theatre or festival? Beginners often assume they can use WiFi or Bluetooth to find that once the theater is full of patrons, signals get slow and spotty. Or maybe you're outdoors at an arts festival? Good luck getting a WiFi signal working out there!

This is where sub-GHz transceivers shine. As long as you aren't trying to transmit a tons of data, you don't have to share any spectrum with 2.4GHz devices and the range is great. 900Mhz (433Mhz in ITU Europe) RF transceivers come in to save the day!

Using Feather Packet Radio boards (RFM69HCW or RFM9X LoRa), you can send encrypted commands at great distances -- 500 meters line of sight for RFM69HCW, and 2 kilometers for LoRa! -- with  no worries about pairing, scanning, and so on. Just a good, old fashioned, magical, invisible wire that connects all of your devices easily!

This guide shows how you can build a versatile controller to take on a nearly limitless variety of remote triggering needs. You'll use a 16-button Trellis pad to send commands, rotary encoder knob to select effects banks, and an OLED display to keep it all straight! 

With the Feather's built-in battery charging circuitry, you can keep the LiPoly battery topped off and ready to go!

Parts and Materials

The essential parts for your controller are:

  • Packet radio Feather microcontroller and antenna as the brains of the transmitter. Your choice of 900MHz for US, 433MHz for ITU Europe, in either M0 or 32u4 processor variant. The RFM69HCW radios are the easiest to set up and a bit less expensive, while the LoRa boards are slightly more involved to set up, but longer range
  • Trellis driver PCB, with silicone keypad for sixteen lighted buttons
  • OLED display FeatherWing
  • Rotary encoder for menu selection

See the right sidebar for specific product links.

On the effects side of things, you'll want additional Packet radio Feathers of the identical frequency and flavor (RFM69HCW or LoRa, you can't mix and match!). These can have any FeatherWing or additional circuits connected to them, depending on what you need to trigger. 

Here are some examples:

  • Music Maker for remote MP3 playback
  • Power Relay to trigger high power, AC devices, such as motors, lamps, and fans
  • DC Motor + Stepper for actuating small DC motors or precisely position things with steppers
  • 8-Channel PWM/Servo to rotate hobby servos (small robot arms...?) or light up lots of standard LEDs 
  • NeoPixels on a 4x8 RGB LED board, or by stringing as many strips of externally powered NeoPixels as you like!

In addition to the parts listed on the sidebar of this guide, you'll also need six screws to fasten the enclosure:

And, if you're 3D printing the enclosure, you'll want some PLA filament for that, such as:

This guide was first published on Apr 29, 2017. It was last updated on Apr 29, 2017.

This page (Overview) was last updated on Apr 26, 2017.

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