Jump to Blog 2:Design for a Cause - The Ultimate Smart Trike Design Blog 2 of 4

INTRODUCTION

We are Sean and Connor Miller from the YouTube Channel Raising Awesome.  I've had a career of diverse roles spawned from an engineering degree and 13 year old Connor - well, I hope he saves the world some day.  We have partnered with Element14.com for the up coming Design for a Cause Challenge.

 

 

 

We recently worked with Element14.com and The Ben Heck show for a Design for a Cause assistive technology project, the Clock Crane.  It is designed to assist taking items between floors for someone who cannot manage stairs with two handed objects.  In our lives, we all have someone we care about that was either born with such an impairment or, as time went on, found themselves with such a physical challenge.  With what is truly a simple application of technology, one's day and thoughts can be stepped closer to the comfort that others enjoy.

 

 

For our next project, we aren't competing in the Design for a Cause challenge, but we are definitely participating.  Our goal is to help inspire others to join the challenge or embark on an assistive technology build of their own - or just find a way to make their ideas come to life that could make the world a better place.  Specifically for this build, we hope to showcase the advantage the MKR1000 IoT kit and the skills you learn when prototyping with it can have when coupled to mechanical components.

 

So, here's our story...when Connor was two years old, his mom (Brenda) was diagnosed with Multiple Sclerosis (MS).  Per current science, MS is considered an auto immune disease where one's own immune system attacks the myelin sheath of the nerves in the brain and spinal cord resulting in what Makers would call "knicks in the wire insulation".  In turn, the nervous system has "shorts to ground".  As time goes on, it typically results in impairment requiring a cane or wheel chair, high fatigue, and numbing pain similar to when one gets the "needles" from their leg falling asleep.

 

The diagnosis of MS starts with motor skill tests that isolate the issue.  Once narrowed down, the diagnosis moves to an MRI and spinal tap.  The MRI shows lighted spots (aka legions) on the brain.  The spinal fluid shows a higher amount of certain proteins.  For Brenda, although there were possibly signs leading up to it, the symptoms escalated suddenly on a trip the took across the God's Country of West Virginia (for you Fallout fans).  The major symptoms subsided slightly so that she no long required a cane until a year ago when they came back worse than ever.  Having moved to east of St. Louis where there are over 80 miles of paved rail trail for walking and biking, this suddenly put a damper on our favorite part of this location.  As Makers, we weren't just going to give up riding.  So, our Design for a Cause project was born.

Brenda of Raising Awesome

 

PROJECT DESIGN

In this assistive technology project to take us back to the trails, we need to establish a means of cycling that addresses the following:

  • poor balance to keep the bike in one's own lane
  • weak grip with the left hand to squeeze the bike brake
  • inability to stand to "torque" up hills
  • inability to step over the center bar to mount the bike
  • general quick fatigue due to left leg pain


To pull this off, we will apply the following assistive technology:

  • Trade in the 2 wheeled bike for a 3 wheeled, low center bar trike
  • 36V 500 RPM motor geared for 11 mph
  • 36V motor controller and thumb throttle
  • (3) 12V batteries
  • MKR1000 IoT kit
  • Additional Design for a Cause Challenge Components
  • ESP8266

Trike

Key features of this Smart Trike will be:

  • Motor interlock due to over tilt
  • Motor interlock when either brake is applied
  • Motor interlock for objects too close
  • Motor interlock if stopped peddling
  • Power Assist braking
  • LCD display of speed, distance, travel time, and interlock status information
  • Garage door opener/closer
  • Data logging for speed, distance, travel time, interlock hits with identifying reason, and tilt
  • Bike Security Alarm
  • Retro Paperboy Arcade Portable - just kidding - that's for a future winter time build

 

BUILD NOTES

Logic Levels:

    • The Ultrasonic Proximity Sensor and the LCD both will need 5V to function properly.  The MKR1000 runs on a 3.3V logic level.  So, any inputs to the MKR1000 need to be 3.3V.
    • On the Ultrasonic Proximity Sensor, you need to put a voltage divider or level shifter on the echo pin.  I used a 680 ohm and 1K ohm voltage divider circuit which took it down to 3.02V on the oscilloscope.
    • On the LCD, the R/W pin (#5) can just be taken to ground.

          SD Card Shield Pinouts:

    • The SD Card shield will use 4 pins.  I'm sure there can be sharing of the pins if one takes some coding precautions, but if you wants to avoid them altogether, here they are:  D4, D8, D9, D10.

 

CLOSING COMMENTS

We appreciate Element14 allowing us to "give back" in our own unique way.  We hope you find our series of four (4) videos and blogs fun, educational, and inspiring.  If you have interest in other skill sets, such as watching Connor learn to weld so he can make the motor mount for this project, check us out on the Raising Awesome channel.  It is the chronicle of Connor's life lessons and life skills development from 9 to 18 where he is learning and sharing how to do every practical skill on our modern planet.

 

-Sean and Connor