ABSTRACT

In some countries , bicycles are a widely used as transport medium inside the cities, its more ecological and also can save you some time when going to some place by avoiding traffic jams.

Bikes do not need to much apparell to make its task, all accessories a user can find on stores are related to security:

1. PROTECTION : Helmet , gloves.
2. SIGNALISATION: Reflective clothes , blinking back light.

Security is an important issue , so i decided to push the blinkling light signalisation system a bit further, the reason is that current systems only provide a mechanism to make others (cars, pedestrians, bikers) see your position, but if you need to turn you still have to take your hand off your steering control and signalise using your arms.

The idea behind B.A.S.S is to automatise the signalisation completely so the biker can focus only on riding, the following features are provided:

• POSITION SIGNALISATION: Green Blinking.
• TURNING: When the bike starts to turn, the inclination is detected by the accelerometer and an orange arrow starts blinking indicating the direction of the turn, the faster the turn is the faster the light blinks.
• BRAKE: When a deceleration is detected, red light is presented to indicate the reduction of speed, the bigger the reduction the faster the light blinks.
• TEXT PRESENTING: Some text strings can be stored on the Arduino’s memory and be displayed on the run.

PARTS

DEVELOPMENT DETAILS

In this projects 3 main goals are to be archieved:

Processing Data from Accelerometer ADLX330. [DONE]

Taking the code from this tutorial at arduino playground is quite easy to start obtaining the values messured by the Accelerometer. Thanks to Ed’s work we obtain continuosly the acceleration values of each axis but also the rotation angle and its pitch.

Interfacing Two LED Matrixes with arduino using 4 MAX7219. [IN PROGRESS]

This LED Matrixes are wonderfull for this project, they consist on 64 (8×8) Two coloured leds, this colors are Red and Green, if the two of them are set at a time, an orange color is emitted, this fits our requirements perfectly. But controling them with an arduino is not easy, they have 24 pins , so the digital outputs of our arduino are not enough, there are some Sparkfun Matrixes with an spi interface that makes it really easy and minimizes the requirements, but they are like 5 times more expensive.

So what we are doing is , buiLow deceleration/inclinationlding this interface from scratch, using MAX7219 chips and following this tutorial, again at arduino playground.

At the very beginning i tried to solder all elements on a prototyping board like this but the number of wires is simply to big and making a mistake by making joints was to easy. So i decided to buy some copper clad laminate and design the PCB myself using EagleCad Layout design software.

Calibrating values from Accelerometer to obtain correct results [TO BE DONE]

Once we have all the setup done, a calibration process must be done. The idea is to search for the correct values of inclination and deceleration to make the system responsive and accurate, there would be 3 diferent intervals to measure:

• Low deceleration/inclination   —>  2 blinks/second T=0,5s
• Medium deceleration/inclination  —>  4 blinks/second T=0,25s
• High deceleration/inclination  —> 8 blinks/second T=0,125s

REFERENCE

http://gizmodo.com/367988/signal-jacket-for-cyclists

http://www.pocket-lint.com/news/news.phtml/13904/14928/reactiv-jackets-wins-dyson-award.phtml

http://www.arduino.cc/playground/Main/LEDMatrix

http://www.arduino.cc/playground/Main/ADXL330

PARTS

http://www.sparkfun.com/commerce/product_info.php?products_id=682

http://www.sparkfun.com/commerce/product_info.php?products_id=692

What is Processing?

For those of you that don´t know it yet .Processing is an open-source enviroment that makes graphic design  easy and totally intuitive for software programmers. Based on a easy-to-learn languaje very very similar to java ( also it can be intergrated with Eclipse or Netbeans) it provides the developer with a very well designed structure and methods that allows points, lines, shapes to be painted on a virtual canvas.

It fits perfect for those who want to give their developments a “pretty face” without having to learn something completely different as we are used to.

Why connecting pc to arduino?

The goal of doing this is obvious, arduino allows us to play with sensors and design interfaces and prototypes over a small/cheap device , all those generated  signals with this sweet tool can be shown by using leds, lcds, servos etc. But the flexibility to design whatever you want to present these data is worthless.

I wonder wich video-”techy”-artist does not use it.

What did i implement?

Taking my Capacitive Bar Sensor , i’ve written some code to make all that input signals come to “reality” , the code ( found below ) reads from serial interface of the laptop ( usb ) a stream of bytes sent by Arduino, each byte represent the pressed position of the bar.

The processing code reads these bytes and makes the correspondent box react. Also, i tried to make these programm recognise some patterns, the possibilities are not too big, so these are the two input patterns detected:

Scroll Up / Down : All the sent bytes are stored in a buffer so we can check wheter they came in a sequential order or not [0][1][2][3][4][5] -> UP  [5][4][3][2][1][0] -> DOWN
Scratch in the middle : if the central positions are “pressed” alternatively [2][3][2][3] -> MIDDLE

Arduino and Processing over Serial from Alejandro Corbi on Vimeo.

Sound

I though that adding sound could be a nice feature, so this implementation can act as a music-interface. It was sooo easy as importing Minim Sound Library to the enviroment and start playing around that i was fully surprised.

Code and sounds

capbardemo.rar

What is capbar?

Is a user input interface concept. Cap stands for “Capacitance” , wich allows us to use nothing but our finger to generate input signals to communicate , in this case with Arduino.

By using very little and cheap amount of materials, just cable and something conductive, a haptic interface can be created and used to provide a posible prototype with an alternative input interface than potentiometers, buttons or switchers.

The good part of it

Easy: So as setting n separated conductive pieces connected each of them to one input pin on arduino.
Cheap: I used conductive tape (something like this) that i found somewhere , you can use whatever conductive material . In addition, the design is quite flexible, a bar is just the easiest  way to implement it.
Responsive: As you can see on the video, the input pins register quite accuratelly the contact between finger and surface. More than one segments can be pressed and detected at the same time.

The bad part of it

Future Roadmap