I am getting started with the Arduino by taking a "Making Gadgets" course in my return to University. For the final project, I will be creating an Arduinio controlled sensor and display system for a manual wheelchair.
At this moment I am looking for which sorts of sensors and parts I will be needing (and if you think this project is feasible for a beginner who is actively learning the basics in a formal class as I go).
We are using the UNO in the class, but it doesn't matter which Arduino we use for the project.
The target user would have paraplegia so leg/foot based controls cannot be used, and the hands need to be kept free to operate the chair. It must be a manual chair since I already have one that I can play around with. Sensors should not be placed anywhere on the hand rims since they are needed to propel the chair.
What I plan to have so far:
1. A display on the back of the chair that can show LEFT, RIGHT, BRAKE, and REVERSE signals (like on a car)
2. When not displaying anything from #1, it should be able to show a custom message (eg "Sit down for what you believe in") that the user can change. For now, I will likely use char arrays in the sketch, but will try use other interfaces to change the messages if I have time.
3. LEFT and RIGHT should be signaled by the user in some way, prior to the turn. My thought is a pair of pressure sensors (1 on each side) on the side of the chair that can be quickly tapped to indicate a turn. The turn signal would turn off after 5 seconds automatically.
4. BRAKE should be automatically detected without input from the user. With a bit of coding work, it shouldn't trigger the display from normal variations in speed - only when the user is actively braking the chair.
5. REVERSE should also trigger automatically. I'm also thinking of adding a speaker to add an audible warning much like large trucks and buses.
Would this part work for measuring both speed changes and changes in direction (Clockwise vs Counterclockwise)? If not, what should I be looking for? http://content.solarbotics.com/products/datasheets/datasheet_idg500.pdf
One sensor that can do both is better than 2 sensors, each doing a different job, but I am open to using 2 sensors as well.
6. Finally, distance sensors that can sound a proximity alarm (or for rear facing sensors, also display a "You're standing too close" message on the display screen).
I would appreciate any advice on which parts to buy and what I should be looking for. I have a bit of a budget, but also don't want to buy $60 parts when a couple of $5 parts will do the same job.