Ok, today has been an interesting day for discoveries.  I was thinking about the limitations of having to have a wired connection between the helmet and main unit on the bike and it got me thinking about Bluetooth and wireless options.

The first thing I discovered (which I wasn’t aware of) is that basic Bluetooth modules (and slave and master pair) can be readily inserted in place of a serial connection between devices.  Unfortunately I don’t think that this would work in the case of driving the Neopixel LED strip that I am planning on using for speed display, but it did point me in the right direction.

What I found was the Adafruit Feather 32u4 Bluefruit LE Arduino development board:

https://www.adafruit.com/products/2829

It’s a fully functional Arduino single board computer with the following features:

• Size: 51mm x 23mm x 8mm
• USB powered
• Built in lithium ion polymer battery charger (!)
• Bluetooth 4.0 Low Energy module
• Heaps of GPIO pins

And it’s cheap (USD$30).  All of this makes it perfect for controlling the LED strip.  It’s small, batter powered, low power consumption, has Bluetooth for communication, and is perfect for controlling LEDs.

I have ordered one to play with and get a feel for Arduino (which I haven’t used before).  So my Raspberry Pi 3 B (which also has Bluetooth 4.0 support) should be able to talk directly to the Feather and issue commands about what light pattern to display.

This means that the helmet components just got more complex, but it should be worth the hassle to have a wire free connection.