To build the transmitter, first solder the short female headers onto the Feather. 

Using the short headers allows us to have a lower profile for the enclosure. Compare the short headers on the left to the regular ones on the right in this CG model.

Next, solder the antenna connector to the bottom of the Feather. OK, maybe my dissection microscope is overkill, but it sure is helpful to have some magnification!

I found it helpful to first tin the pads, then hold the part to the board while reheating the solder.

Now, snap on the antenna connector cable.

Thread on the antenna and you're ready to transmit!

Solder short male header pins onto the OLED FeatherWing.

Here's a quick test fit of the OLED and Feather together again for the first time.

Trellis Time

Prep your Trellis board and 16 LEDs for a fun solder party. Please note, all of the through holes have a "+" sign to mark the positive hole -- place the longer legged anode side of each LED into these.


Push each LED through, bend the legs, and then flip the board over for soldering.

After soldering, clip the legs off. Sorry legs.

The connections from the Trellis to the Feather are SDA, SCL, GND, 5V, and INT. 

Look at the breadboard diagram below to see the connections that will be made. We will actually solder the connections to the inner row of pin holes on the OLED FeatherWing, as seen in the second diagram and the photographs.

We'll drive the LEDs from the 3.3V output of the Feather, which works just fine.

Solder a 6" length of wire to each by tinning the pads, tinning the wires, and then heating them together.

Next, solder the Trellis wires to the inner row of the OLED FeatherWing, pushing the wires up from underneath.

See those long pieces of excess wire tips protruding from the top of the board?? Clip them off!


I absolutely love the Feather boards because they take care of so many functions for you without need of extra hardware! Case in point -- there is a built in LiPoly battery port and charging circuit as well as an Enable pin that can be used to make a neat little on/off switch without splicing battery wires.

Let's wire up the slide switch.

Strip and tin the short yellow wires, and add some heat shrink tubing. Tin the middle and one of the outer legs of the switch, then solder on the two wires and heat the tubing.

Tin one of the free GND pads on the Trellis and then solder on one of the yellow switch wires, it doesn't matter which one, all we're using the switch for is to tie the En pin to GND or not!

Solder the other yellow switch wire to the En pin on the OLED FeatherWing.

Here's the finished power switch, as well as a test fit to see how the wiring is routed between the FeatherWing and Feather.

Rotary Encoder Switch

The final component to solder on is the rotary encoder.

Again, solder the wiring to the proper pins on the OLED FeatherWing from below.

For the black GND wire, since there isn't a free one on the FeatherWing, use another GND pad on the Trellis.

Now, solder each wire to the rotary encoder, as shown in the diagram above and the animation below. Note, a short length of wire is used to connect the two GND pins of the encoder.

This guide was first published on Apr 29, 2017. It was last updated on Mar 08, 2024.

This page (Build the Transmitter) was last updated on Apr 25, 2017.

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