To wire up the battery power supply for the circuit, tin the long leads of your on/off switch with solder.

You may also wish to extend the switch leads even longer with pieces of wire.
Tin the leads of your 2-pin JST cable. Solder one switch lead to the JST cable's red wire, and the other switch lead to the battery pack's red wire. If your battery pack doesn't have different colored wires, use your multimeter to determine which is the positive lead.

Also solder the JST cable's black wire to the battery pack's black wire.
Use a 3xAA battery pack for this project. If you don't have one handy, you can bridge across one of the compartments on a 4xAA battery pack-- just solder a wire to each end.

Attach the Flora accelerometer according to the circuit diagram. Notice that all four pins necessary for this i2c sensor are in a row, making wiring very convenient!

Affix the Flora board and accelerometer to the battery pack with Velcro tape. Likewise between the battery pack and plastic enclosure.
RF Module

These simple wireless receiver/remote pairs are great for adding a few wireless inputs to your project, but they operate at 5V, which doesn't match Flora's 3V i/o. So build a simple voltage divider with two 4.7K ohm resistors!

To attach to Flora, twist the resistor leads together and solder to a digital input pin. Repeat with more pairs of resistors for each button on your remote or as many as you'd like to use.

One resistor in each pair will be soldered to ground, and the other will connect to the RF module's output.

Female jumper wires can come in handy for attaching to the RF module's header pins. The pin marked +5V gets connected to VBATT on Flora, and GND goes go GND.

Pixel connector

Plug an extender onto the input side of a strand of weather-resistant LED pixels.

Run the connector cable through a small hole bored in the plastic weather-resistant enclosure.
Use colorful heatshrink tubing to mark the pixel connectors wires, corresponding to the colord wires in the pixel strand. You could also use pieces of taped marked with a letter-- this makes it a lot easier to attach the wires to the Flora correctly.
Connect the four pixel connector wires as per this diagram - red to VBATT, blue to GND, yellow to D10 and green to D9.

These tactile on/off switches are perfect for toggling power on our backpack, but the switch isn't inherently waterproof. Using a bit of plastic to prevent the button from being clogged, wrap the switch in Sugru and let it cure for 24 hours. Wear gloves to prevent fingerprint marks.
Use a ziptie for strain relief on any wires exiting the enclosure.
For maximum range between the RF remote/receiver pair, uncoil the receiver's antenna wire so it runs along the outer edge of the enclosure.
More Sugrue helps waterproof the hole in the enclosure.

This guide was first published on Feb 13, 2013. It was last updated on May 19, 2024.

This page (Control Circuit) was last updated on Mar 08, 2024.

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