Learn how to build a secure and efficient Lenticular Clock with Arduino!
After making my Moire Clock a got interested in a very similar effect: lenticular animations. You probably have seen this effect before, e.g. on post cards. I remember having a ruler in primary school with a picture of dinosaurs on it that changed depending on the viewing angle.
Choosing the Right LPI.
Creating the Lenticular Print
Attaching the Print to the Lenticular Sheet
Because of manufacturing tolerances of the lenticular sheet and also tolerances of your printer you need to determine the exact LPI value that you will use for interlacing. There are several softwares that can generate calibration sheets. I tried out the software from 3Dependable and fPitch. For some reason though the calibration did not work very well and I ended up generating the final print with different LPI values and then chose the one which gave the best results when placed below my lenticular sheet.
There are several softwares that can be used for interlacing the images, I used grape which is freeware. At first, I created pictures of each individual digit from 0 to 9 all with the same size of 52.5x30mm. I used a different color for each digit which helps to distinguish them more clearly and also has the advantage of being able to participate in the "colors of the rainbow" contest on instructables ;-)
/*
State change detection (edge detection)
Often, you don't need to know the state of a digital input all the time, but
you just need to know when the input changes from one state to another.
For example, you want to know when a button goes from OFF to ON. This is called
state change detection, or edge detection.
This example shows how to detect when a button or button changes from off to on
and on to off.
The circuit:
- pushbutton attached to pin 2 from +5V
- 10 kilohm resistor attached to pin 2 from ground
- LED attached from pin 13 to ground through 220 ohm resistor (or use the
built-in LED on most Arduino boards)
created 27 Sep 2005
modified 30 Aug 2011
by Tom Igoe
This example code is in the public domain.
https://www.arduino.cc/en/Tutorial/BuiltInExamples/StateChangeDetection
*/
// this constant won't change:
const int buttonPin = 2; // the pin that the pushbutton is attached to
const int ledPin = 13; // the pin that the LED is attached to
// Variables will change:
int buttonPushCounter = 0; // counter for the number of button presses
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button
void setup() {
// initialize the button pin as a input:
pinMode(buttonPin, INPUT);
// initialize the LED as an output:
pinMode(ledPin, OUTPUT);
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// read the pushbutton input pin:
buttonState = digitalRead(buttonPin);
// compare the buttonState to its previous state
if (buttonState != lastButtonState) {
// if the state has changed, increment the counter
if (buttonState == HIGH) {
// if the current state is HIGH then the button went from off to on:
buttonPushCounter++;
Serial.println("on");
Serial.print("number of button pushes: ");
Serial.println(buttonPushCounter);
} else {
// if the current state is LOW then the button went from on to off:
Serial.println("off");
}
// Delay a little bit to avoid bouncing
delay(50);
}
// save the current state as the last state, for next time through the loop
lastButtonState = buttonState;
// turns on the LED every four button pushes by checking the modulo of the
// button push counter. the modulo function gives you the remainder of the
// division of two numbers:
if (buttonPushCounter % 4 == 0) {
digitalWrite(ledPin, HIGH);
} else {
digitalWrite(ledPin, LOW);
}
}