Build the Drawer Actuator Circuit

The actuator circuit consists of the RFM69 Feather M0 with antenna, the motor controller FeatherWing, the linear actuator, 12V 5A DC power supply for the motor, and LiPo battery or 5V DC power supply for the Feather.

Here's what the circuit looks like before the FeatherWing is placed on top of the Feather. Note, the battery will be plugged into the battery extension cable ON/OFF switch, represented here by the in-line slide switch.

This is the circuit after the FeatherWing has been placed on top of the Feather.

Prep the Feather M0 by soldering on the female socket headers, as seen here.

Assemble the Motor FeatherWing as shown here.

Get out your jeweler's loupe and solder on the antenna connector to the back of the Feather board! This link will show you how. Then, screw on the antenna to the cable, and connect it to the uFL jack.

The Motor FeatherWing needs a separate 12V power supply to run the motor, vs. the small LiPo or 5V supply that will power the Feather. We'll clip the end off of the 12V supply (make sure it isn't plugged in first!) and screw it's wires into the FeatherWing power terminals.

Optionally, you can use a power jack adapter if you'd like to keep your plug intact! https://www.adafruit.com/product/368

Clip the plug off, then carefully remove some outer insulation to expose the two wires within. One will be uninsulated, so twist it together. The other has insulation, remove a bit of that, then twist this end, too.

This is very important! Use a multimeter to determine the polarity of the two wires. Plug in the supply, and set your voltmeter to DC. Touch the probes to the wires and watch for a positive voltage of around 12V. If this is negative, switch the probes and try again. Once you've determined which is positive (in the case shown here, the wire with the white insulation is positive) note this down. This will be the wire you screw into the + terminal on the Motor FeatherWing.

I added some heat shrink tubing, color coded red for + and black for GND.

Double check the polarity one last time, then insert the wires into the Motor FeatherWing's power terminals -- positive to positive, negative to negative -- and screw them down tightly.

Next, you can insert the two wires of the linear actuator into one of the motor port pairs on the FeatherWing. You can place either wire into either terminal of any port (M1 in this case) as the motor is bi-directional, and can be reversed in software or in the real world later if you like.

This circuit is ready for coding!

This guide was first published on Aug 25, 2017. It was last updated on Aug 25, 2017. This page (Build the Drawer Actuator Circuit) was last updated on Jul 16, 2019.