final: north bracelet

antanaityte.gerda@iaac.net — Sun, 02 Dec 2012 19:17:18 +0000

Here’s the final prototype of north bracelet. During the process I’ve learned a lot about electronics (thanks for Alex). Here are some core hints:

For this application input was tilt compensated compass (CMPS10), outputs were 3 high luminosity leds.
First prototype was made on breadbord to check how it works and to program arduino fio.
To make it portable the circuit had to be replaced and soldered on smaller breadbord.
There were few tricky moments: first of all, because of different voltage, leds didn’t want to shine enough bright. Transistor, which was helpful using power supply from computer appeared useless with lithium battery. The circuit was effected by removing it.
Reflecting tape was used to increase brightness of leds. But everytime I sticked tape on panel, leds used to stop lightning. It appeared that tape worked as well as the conductor. To solve it I put some extra isolation on metal parts of leds.
I had to change some components’ positions and cut out part of bread bord to place everything into the box. And finally it worked.
Arduino fio doesn’t have usb port for programming. It requires special cable with pins.

Below you can see pictures of the process and final result, video and some technical data as well.

final prototype:

process:

circuit scheme:

code:

#include
#define ADDRESS 0×60
void setup(){
Wire.begin(); // Conects I2C
Serial.begin(9600);
}
void loop(){
byte highByte, lowByte, fine;
char pitch, roll;
int bearing;
int bright;
Wire.beginTransmission(ADDRESS);
Wire.write(2);
Wire.endTransmission();
Wire.requestFrom(ADDRESS, 4);
while(Wire.available() < 4);
highByte = Wire.read();
lowByte = Wire.read();
pitch = Wire.read();
roll = Wire.read();
bearing = ((highByte<<8)+lowByte)/10;
fine = ((highByte<<8)+lowByte)%10;
Serial.print(“Angle ”);
Serial.println(bearing);
if ((bearing > 15) and (bearing < 344)) {
bright = 255;
}
else if ((bearing < 15) and (bearing >= 0)) {
bright = map (bearing, 15,0,255,0);
}
else if ((bearing >344) and (bearing <= 359)) {
bright = map (bearing, 344,359,255,0);
}
analogWrite (9, bright);
delay(20);
}
int soft_ver(){
int data;
Wire.beginTransmission(ADDRESS);
Wire.write((byte)0);
Wire.endTransmission();
Wire.requestFrom(ADDRESS, 1);
while(Wire.available() < 1);
data = Wire.read();
return(data);
}

in process: north bracelet

antanaityte.gerda@iaac.net — Tue, 27 Nov 2012 23:29:04 +0000

Are you extremely stylish? But afraid to get lost in the forest while picking mushrooms? Well, this is exactly what you need!

If to be more serious, this is small project to get more familiar with electronics: arduino, sensors, actuators and coding. I decided to fabricate bracelet witch’s strength of light depends on compass position. More north it is directed – brighter it shines. The main component for this application is tilt compensated compass module CMPS10. Also I use ‘arduino fio’ (3.3V), which is smaller than classical ‘arduino uno’ and adapted for lithium lon battery. It can be charged using usb cable. To illuminate bracelet panel I got 3 high luminosity, white diffused leds’. Below you can see photos of creative process:

I started from super simple step. Circuit scheme of lights and it’s test with arduino uno.
Then I’ve cut few prototypes to test how different materials diffuse light. Finally Alex’s advice was to stay with crystal acrylic.
Second version was adapted to insert led’s inside and engraved north sign has nice luminous effect.
and challenge which is still waiting is to put everything together and make it work..

Physical computing » compass

final: north bracelet

in process: north bracelet