I wanted to make a ghost chat which would allow the user to interact with “ghosts” that I programmed to be “detected” by a photosensor. By pushing the button, the user can ask questions and get an answer. I also initially wanted to program a theme song for each ghost that could run in the background or when someone asks for the ghosts’ favorite song, but that took a backseat when I realized how confused I actually was by interrupts. If I were to really make this perfect, I’d probably find a different sensor, and figure out a way to have the ghost answer questions that the user defines, as opposed to pre-programmed answers to pre-programmed questions.
This project is supposed to be an embodiment of Steve Reich’s Clapping Music. The code for this project has two versions. The first version works unreliably because it uses the delay function to time the LEDs. The second uses a helper function to time and illuminate the LEDs using millis(). This program does not even finish compiling though. It probably just needs debugging, but I am not sure. With the original program, the interrupt does not reliably switch the case. To continue this project, I will use solenoids to make a percussive sound.
The circuit shown above is a 3 pin led connected to a joystick. It uses the JoyStick movement to change the RGB values and the button press in the joystick is used to switch between states. The system has 5 states
All off
Red constant, change G and B by moving the joystick
Green constant, change R and G by moving the joystick
Blue constant, change others through joystick
All on.
Reflection: if I were to redo this, I would transfer the states from 2, 3 and 4 making it a real color picker, and I also think the joystick button may not be ideal for an interrupt.
I wanted to build upon and improve the previous assignment. The goal is to balance at a certain distance in order to turn on the LED, but done through a classic game of hot or cold. While it’s rather trivial, it has helped me to better understand the ultrasonic sensor and its possibilities. refining the sensor data and perfecting the timing is something that I’d like to explore further down the road.
The states are used in order to guide you through the game. State one lets you now that the game is ready, state two sets a random number for you to find using the ultrasonic sensor, and in state three…you find the number. Prompted in the serial monitor if you are getting warmer or colder.
void SwitchPressed() { if(digitalRead(switchPin)== HIGH){ // this is why people hate C
buttonState ==3? buttonState =0: buttonState++; } // Serial.println(buttonState); }
// attach the interrupt pin to a method if(isInterrupt){
attachInterrupt (digitalPinToInterrupt (switchPin), SwitchPressed, CHANGE); }
randomSeed(analogRead(2));
pixels.begin();// This initializes the NeoPixel library. }
void pixelBlinkGreen(){
pixels.setPixelColor(0, pixels.Color(0, 255, 0));
pixels.show();// This sends the updated pixel color to the hardware.
delay(500);
pixels.setPixelColor(0, pixels.Color(0, 0, 0));
pixels.show();// This sends the updated pixel color to the hardware.
delay(500); }
void pixelBlinkYellow(){
pixels.setPixelColor(0, pixels.Color(255, 200, 0, 75));
pixels.show();// This sends the updated pixel color to the hardware.
delay(250);
pixels.setPixelColor(0, pixels.Color(0, 0, 0));
pixels.show();// This sends the updated pixel color to the hardware.
delay(250); }
void pixelBlinkWhite(){
pixels.setPixelColor(0, pixels.Color(255, 255, 255));
pixels.show();// This sends the updated pixel color to the hardware.
delay(300);
pixels.setPixelColor(0, pixels.Color(0, 0, 0));
pixels.show();// This sends the updated pixel color to the hardware.
delay(250); }
void pixelBlinkPink(){
pixels.setPixelColor(0, pixels.Color(254, 6, 141));
pixels.show();// This sends the updated pixel color to the hardware.
delay(300);
pixels.setPixelColor(0, pixels.Color(0, 0, 0));
pixels.show();// This sends the updated pixel color to the hardware.
delay(250); }
void pixelOff(){
pixels.setPixelColor(0, pixels.Color(0, 0, 0));
pixels.show();// This sends the updated pixel color to the hardware. }
Goal: The goal for my state machine was to build a basic alert system that tells you when there is someone/something in the proximity. The switch is the state change that turns the entire alert system on or off. This is essential for the edge case when you are expecting many people and do not need to be alerted. There were three LED colors: yellow for idle (nothing in the proximity), red for something physically there and it is light out, and green for something physically there and it is dark out.
Reflection: If I were to update/re-do this, I would change the code so the interrupt is the proximity sensor rather than the switch. I would also change the light so the green represents light and proximity and red represents dark and proximity. This would align with my overarching ideal goal to make a front door security system. I would also change the light/dark reading to a boolean.
(My unstable hand is to blame for the flickering green light)
// Define constant values.
// The wiring assignment.
#include
static const int SWITCH_PIN = 3;
static const int LED1Pin = 4;
static const int LED2Pin = 5;
static const int LED3Pin = 13;
static const int lightSensor = A0;
bool LEDState = false;
static const int sampleSize = 16;
unsigned int readings[sampleSize];
unsigned int sampleIndex = 0;
static const int nighttime = 50;
const int TRIG_PIN = 9;
const int ECHO_PIN = 8;
const int MAX_DISTANCE = 700;
// ================================================================================
// Configure the hardware once after booting up. This runs once after pressing
// reset or powering up the board.
void setup()
{
// Initialize the serial UART at 9600 bits per second.
Serial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT);
pinMode(SWITCH_PIN, INPUT);
pinMode(LED1Pin, OUTPUT);
pinMode(LED2Pin, OUTPUT);
pinMode(LED3Pin, OUTPUT);
pinMode(lightSensor, INPUT);
pinMode(TRIG_PIN, OUTPUT);
digitalWrite(TRIG_PIN, LOW);
// Initialize the echo pin for input.
pinMode(ECHO_PIN, INPUT);
// ================================================================================
// Run one iteration of the main event loop. The Arduino system will call this
// function over and over forever.
int median = 0;
int low = 1024;
int high = 0;
int mean = 0;
for (int i = 0; i < sampleSize; i++) {
mean += readings[i];
if (readings[i] < low) { low = readings[i]; } if (readings[i] > high) {
high = readings[i];
}
}
mean = mean / sampleSize;
bubbleSort();
median = readings[sampleSize / 2];
//TURNED ON, IDLE STATE
if (LEDState && sonar.ping_median() < 700 && mean > nighttime ) {
digitalWrite(LED1Pin, 255);
digitalWrite(LED2Pin, 0);
digitalWrite(LED3Pin, 0);
}
else if (LEDState && sonar.ping_median() < 700 && mean < nighttime ) {
digitalWrite(LED1Pin, 0);
digitalWrite(LED2Pin, 0);
digitalWrite(LED3Pin, 255);
}
Imagine your desks, doors, and floors turning into an interface that responds to knocks. What if you could control room lighting with the silent knocks? What if you could customize the knock interaction for each object? In this assignment, I built an interactive system that is able to detect and record knock patterns. Used a piezo sensor to detect the knock vibrations and a button to trigger interrupt to switch 2 different modes – detect and record. Knock detection result is displayed on a console.
The system consists of 6 states in total – wait / read / output for detect mode and wait / read / record for record mode.
Due 23:59, 29 January 2018. We will discuss in class on the 30th and suggest improvements or analyze different ways to resolve your problem.
Requirements
State a question or process you would like to solve. (Ex: “control the lights in a room based on a door being opened and curtains being opened or closed.”) Create a physical interaction using a state machine driven by inputs and interrupts that collects data, interprets the data, then displays a result via console, LEDs, or other output devices. Speakers are acceptable but must be executed in a useful manner, kinematic solutions are also welcome.
The state machine should have at least three states not including on and off states. Declare whether your states have an order or if any state can transition to another state.
Post a short video showing the various states, I suggest vimeo or youtube. For your Arduino and Fritzing sketches, make a zip file or gzip/tar bundled and post that to the blog.
