ROTOR
For the one week curiosity cabinet...
Scrolling text is projected onto the back of the cabinet. The scrolling text was achieved by running a small camera over printed text using a motor and old printer chassis. The direction of the motor was controlled by an Arduino, some switches, and relays.
This project is a prototype for a larger piece where the concept relies on motion controlled cameras and video switchers to create continuous scrolling text. The basic idea is illustrated below.
...the Arduino code - bits and pieces pulled from the ardunio site:
int switchPin = 2; // switch input
int motor1Pin = 3; // H-bridge leg 1
int motor2Pin = 4; // H-bridge leg 2
int speedPin = 9; // H-bridge enable pin
int ledPin = 13; //LED
int led2Pin = 6;
int inPin = 2; // the number of the input pin
int outPin = 13; // the number of the output pin
int state = HIGH; // the current state of the output pin
int reading; // the current reading from the input pin
int previous = LOW; // the previous reading from the input pin
// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0; // the last time the output pin was toggled
long debounce = 200; // the debounce time, increase if the output flickers
void setup() {
// if (DEBUG)
Serial.begin(19200);
pinMode(inPin, INPUT);
pinMode(outPin, OUTPUT);
// set the switch as an input:
pinMode(switchPin, INPUT);
// set all the other pins you're using as outputs:
pinMode(motor1Pin, OUTPUT);
pinMode(motor2Pin, OUTPUT);
pinMode(speedPin, OUTPUT);
pinMode(ledPin, OUTPUT);
pinMode (led2Pin, OUTPUT);
// set speedPin high so that motor can turn on:
digitalWrite(speedPin, HIGH);
// blink the LED 3 times. This should happen only once.
// if you see the LED blink three times, it means that the module
// reset itself,. probably because the motor caused a brownout
// or a short.
blink(ledPin, 3, 100);
}
void loop() {
reading = digitalRead(inPin);
// if the input just went from LOW and HIGH and we've waited long enough
// to ignore any noise on the circuit, toggle the output pin and remember
// the time
if (reading == HIGH && previous == LOW && millis() - time > debounce) {
if (state == HIGH)
state = LOW;
else
state = HIGH;
time = millis();
}
digitalWrite(outPin, state);
previous = reading;
// if the switch is high, motor will turn on one direction:
if (digitalRead(switchPin) == HIGH) {
digitalWrite(motor1Pin, LOW); // set leg 1 of the H-bridge low
digitalWrite(motor2Pin, HIGH); // set leg 2 of the H-bridge high
}
// if the switch is low, motor will turn in the other direction:
else {
digitalWrite(motor1Pin, HIGH); // set leg 1 of the H-bridge high
digitalWrite(motor2Pin, LOW); // set leg 2 of the H-bridge low
}
}
/*
blinks an LED
*/
void blink(int whatPin, int howManyTimes, int milliSecs) {
int i = 0;
for ( i = 0; i < howManyTimes; i++) {
digitalWrite(whatPin, HIGH);
delay(milliSecs/2);
digitalWrite(whatPin, LOW);
delay(milliSecs/2);
}
}
