On Saturday I took the train and my bicycle up to San Francisco. I wanted to get from the train station to Hyde Street Pier. I had printed out some instructions, from 511.org, but I found them less than helpful as I was trying to bike.
This lead me to the following concept, which I'm thinkin about
building from an Arduino as a prototype.
A simple console with several LEDs and one or two buttons (I haven't fully baked the user interface yet). The cheap version of this device would be programmed by connecting it to a computer via USB.
I'm envisioning an LED layout like:
(1) (2) (3)
(1) would indicate the next turn is to the left
(2) indicates the next manuever is forward
(3) indicates that the next maneuver is right
(5) in combination with (1, 2 or 3) indicates that the maneuver is a U-Turn in the indicated direction
The (4) LED blinks shortly before you arive at the next maneuver.
Programming it uploads a set of distances and maneuvers (turn left, turn right, go forward). A more sophisticated version could be programed from a smart phone using bluetooth. Multiple routes could be uploaded and selected using the buttons.
I'm thinking you would hold down the start button for 3-seconds then use the NEXT button to choose one of 8 pre-loaded routes (using the first 3 LEDs as a binary counter to indicate the selected route). Then, when you press the start button again the appropriate LED for the NEXT maneuver would light up (the display will always be for the upcoming manuever). As you near the waypoint, the center LED would blink faster and faster and go solid on when you reach the waypoint.
Upon reaching a waypoint, the user needs to acknowledge the maneuver by pressing the "NEXT" button. The computer then lights the appropriate LED indicating the direction of the next maneuver and starts counting down until it reaches the next waypoint.
This seems like it could be built for not much more money than bike computers that cost between $25-50, and would not require a lot of the rider's attention (as compared to trying to follow written instructions as I was.
A nice graphical interface would be even better (and the whole thing would be a minor enhancement to an existing bike computer).
An audible buzzer would also be a likely useful improvement. It would ring at the point just before you reach your waypoint.
A deluxe model that included an electronic compass and/or an accelerometer might also be possible.