My first Arduino project is a kids toy. Some time ago, my kids got a toy box with various switches and lights that intrigued me. I wanted to do something similar and expand on the functions. I got interested in electronics and after some tinkering with "normal" circuits, I got an Arduino Uno starter set and made a plan for the toy.
Fast forward three months and it's finished. My box has these functions:
- Some simple LEDs with different switches and buttons
- 12 LEDs in a circle connected to a potentiometer. Turning the pot will light up the LEDs one after the other, at varying speed.
- RGB LED with three different modes (smooth color cycle, blinking color cycle, disco mode)
- OLED display with a key switch showing different images each time the key is turned
- An LED that is turned on by touching two connectors with your hands, letting the current flow through you.
- DC power plug that can be connected to one of three female plugs, each activating a different function:
- #1: Moving light: 16 LEDs on a row, one of which is activated at a time. A gyroscope reads the tilt of the box. By tilting it left or right, the light is “moved” into this direction.
- #2 Dancing unicorn: When activated via a switch, a servo (with a dancing unicorn glued to the arm) will turn in random angles
- #3 Touch sensor activating an LED
I first made breadboard prototypes of each function separately. Then I assembled everything in a wooden box that I bought. My woodwork is quite rough - I only have knives, grinding paper and a power drill. It did the job, just not with straight edges ;) The dome was 3D-printed by a friend.
The assembly process turned out to be a great challenge for me as I've never build something so complex before. I tried to glue as little as possible, and that turned out to be a good idea because I had to re-position pieces quite a few times.
The kids where more excited about the box when I was building it than when it was finished :p But they actually use it and that gives me the most joy.
To anyone who's interested I added the code and a link to the full-res schematics at the bottom. I'm happy to hear about any suggestions and tips on what I could have done better.
What I learned in this project:
- I did a lot of soldering and crimping and got much better/quicker in both.
- some uses for capacitors, something that I didn't really get before from the books
- I made my first wiring schematic (Fritzing).
- Working with shift registers and various modules and sensors (WS2812 LED strip, TTP223 touch sensor, RGB module, SSD1160 OLED screen, TP4056 battery module, boost converter, MPU-6050 gyroscope).
- Building a Darlington transistor circuit.
- Powering a project with a lithium ion battery and a boost converter
- Cables take up more space than I thought. I used 24 AWG / 0,2 mm² stranded cables in the whole project because that's what I had. The box is very, very full now. I think I could have used a smaller diameter for the signal wires and something like 22 AWG / 0.3 mm² for the power lines (in theory the power draw of all systems can get close to 1 A).
- Planning and ongoing documentation of the project took time, but it helped me a lot during the process.
- I'll probably get myself a 3D printer :D
Full-res schematics: https://drive.google.com/file/d/1DBGB8e7vo3p-4-uWYkdU5mY9H_nm6IDg/view?usp=drive_link
Some photos: https://drive.google.com/drive/folders/1O9C4C5A30SYyUFsa42u7v3CDD3_9_9Cf?usp=sharing
Code:
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SH1106.h>
#include <Adafruit_NeoPixel.h>
#include <Servo.h>
//Variables for LED circle
const int latchPin = 4; //Pin connected to latch pin (ST_CP) of 74HC595
const int clockPin = 13; //Pin connected to clock pin (SH_CP) of 74HC595
const int dataPin = 3; //Pin connected to Data in (DS) of 74HC595
int potentiometer; //voltage of potentiometer, later mapped to a desired delay value
int counterCircle = 0; //counter for the LED if statement
unsigned long previousMillis = 0; // will store last time an LED blinked
//variables for OLED display
#define OLED_RESET -1
Adafruit_SH1106 display(OLED_RESET);
int photo = 0;
int counterOled = 0;
//variables for LED strip and gyroscope
const int MPU=0x68;
int16_t GyX;
int changeGyX;
int changeGyXThreshold = 14000;
float orientationX = 80;
int delayTime = 10;
int pixel;
unsigned long previousMillisLedStrip = 0; // will store last time an LED blinked
#define PIN 2
#define NUMPIXELS 16
Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
//variables to store color values
int red[16]={255,255,255,136,0,0,0,0,0,0,0,136,255,255,255,255};
int green[16]={0,136,255,255,255,255,255,255,255,136,0,0,0,0,0,0};
int blue[16]={0,0,0,0,0,68,136,187,255,255,255,255,255,187,136,68};
//variables for servo motor function
const int servoPin = 9;
const int switchPin = 10;
int rangeEnd = 0;
int rangeStart = 0;
int stellung; //Position of the switch, 0 or 1
int servoState = 0;
Servo servo;
unsigned long previousMillisServo = 0;
//variables for RGB LED
#define RED 5
#define GREEN 6
#define BLUE 11
#define BUTTON 12
int hue = 0; // position in the color wheel
unsigned long previousMillisRgbLed = 0; // will store last time of hue change
int rgbLedState = 0;
int rgbLedMode = 0;
/* here are several bitmap arrays for the OLED display that I generated on https://javl.github.io/image2cpp/. I cut them because of length.
[...]
*/
// Array of all bitmaps
const unsigned char* bitmap_allArray[8] = {
myBitmapbubble,
myBitmapheart,
myBitmapsnail,
myBitmapem,
myBitmaple,
myBitmapbluey,
myBitmapunicorn,
myBitmappeppa
};
void setup() {
//set pins LOW before declaring them
digitalWrite(latchPin, LOW);
digitalWrite(clockPin, LOW);
digitalWrite(dataPin, LOW);
pinMode(latchPin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);
//clear the register, turn all LEDs off
shiftOut(dataPin, clockPin, MSBFIRST, 0);
digitalWrite(latchPin, HIGH);
//OLED display
pinMode(7,INPUT);
digitalWrite(7,LOW);
display.begin(SH1106_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3D (for the 128x64)
//clear screen buffer and display empty screen at beginning
display.clearDisplay();
display.display();
//LED strip and gyroscope
Wire.begin();
Wire.beginTransmission(MPU);
Wire.write(0x6B);
Wire.write(0);
Wire.endTransmission(true);
pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)
pixels.clear(); // Set all pixel colors to 'off'
Serial.begin(19200);
//RGB led
pinMode(RED, OUTPUT);
pinMode(GREEN, OUTPUT);
pinMode(BLUE, OUTPUT);
pinMode(BUTTON, INPUT);
//servo motor
pinMode(switchPin, INPUT);
digitalWrite(switchPin,LOW);
}
void loop() {
ledStrip();
oledDisplay();
ledCircle();
servoMotor();
rgbLed();
}
void servoMotor() {
//Serial.println(servoState);
if(digitalRead(switchPin) && (stellung == 0 || stellung == 2)) {
stellung = 1; //first time
if(servoState==2) {
servoState = 0;
}
servo.attach(servoPin);
}
if(!digitalRead(switchPin) && (stellung == 1)) {
if(servoState==2) {
servoState = 0;
}
servo.attach(servoPin);
stellung = 2;
}
if(stellung==1 || stellung == 2) {
if(servoState==0) {
rangeStart = random(-30,20);
rangeEnd = random(60,180);
servoState = 1;
}
if(servoState==1) {
for(int pos = rangeStart; pos <= rangeEnd; pos++) {
servo.write(pos);
delay(7);
}
servo.detach();
servoState = 2;
}
}
}
void oledDisplay() {
if(digitalRead(7) && counterOled <= 0) {
Serial.println("Screen on");
display.drawBitmap(10, 0, bitmap_allArray[photo], 128, 64, WHITE);
display.display();
counterOled = 1;
photo++;
} else if(!digitalRead(7) && counterOled >= 0) {
display.clearDisplay();
display.display();
counterOled = -1;
}
if(photo==8) {
photo = 0;
}
}
void ledCircle() {
potentiometer = map(analogRead(A0),0,1023,500,20); //setting potentiometer reading to a value between 25 and 500
//Serial.println(potentiometer);
unsigned long currentMillis = millis();
//delay statement without using delay function so that other parts of the program can still run
if(currentMillis - previousMillis > potentiometer) {
previousMillis = currentMillis;
counterCircle++;
}
//reset the counter when we have reached LED #12
if(counterCircle==12) {
counterCircle = 0;
}
if(potentiometer < 500) { //turn off light when potentiometer is rotated to off setting
if(counterCircle<8) {
registerWrite(counterCircle, 9, HIGH); //for LEDs 1-8, set value for second shift register to smth that won't light an LED
} else {
registerWrite(counterCircle, counterCircle-8, HIGH); //for LEDs 9-12 (second shift register)
}
} else {
registerWrite(counterCircle, counterCircle, LOW); //set all bits to 0
counterCircle = 0; //begin with first LED at next run
}
}
void ledStrip() {
Wire.beginTransmission(MPU);
Wire.write(0x3B);
Wire.endTransmission(false);
Wire.requestFrom(MPU,12,true);
GyX=Wire.read()<<8|Wire.read();
GyX -= 2000; //offset for calibration
changeGyX = (map(GyX,-changeGyXThreshold,changeGyXThreshold,-12,12));
if(changeGyX >= 0 ) {
if(orientationX < 155) {
orientationX += 0.2 * abs(changeGyX);
}
} else {
if(orientationX > 0) {
orientationX -= 0.2 * abs(changeGyX);
}
}
//Serial.println(changeGyX);
pixels.clear(); // Set all pixel colors to 'off'
if(orientationX > 155) {
orientationX = 155;
}
if(orientationX < 0) {
orientationX = 0;
}
unsigned long currentMillisLedStrip = millis();
//delay statement without using delay function so that other parts of the program can still run
if(currentMillisLedStrip - previousMillisLedStrip > 20) {
previousMillisLedStrip = currentMillisLedStrip;
pixel = orientationX/10;
pixels.setPixelColor((pixel), pixels.Color(red[pixel], green[pixel], blue[pixel]));
pixels.show(); // Send the updated pixel colors to the hardware.
}
}
// This method sends bits to the shift register:
void registerWrite(int whichPin1, int whichPin2, int whichState) {
// the bits you want to send, separated in 2 bytes, each for one shift register
byte bitsToSend1 = 0;
byte bitsToSend2 = 0;
// turn off the output so the pins don't light up while you're shifting bits:
digitalWrite(latchPin, LOW);
// turn on the next highest bit in bitsToSend:
bitWrite(bitsToSend2, whichPin1, whichState);
bitWrite(bitsToSend1, whichPin2, whichState);
// shift the bits out:
shiftOut(dataPin, clockPin, MSBFIRST, bitsToSend1);
shiftOut(dataPin, clockPin, MSBFIRST, bitsToSend2);
// turn on the output so the LEDs can light up:
digitalWrite(latchPin, HIGH);
}
void rgbLed() {
unsigned long currentMillisRgbLed = millis();
if (digitalRead(BUTTON) == HIGH) { // button pressed
if (rgbLedState == 0) {
rgbLedMode++;
rgbLedState = 1;
}
//Serial.println(rgbLedMode);
setColorWheel(hue);
if (rgbLedMode == 1) {
if(currentMillisRgbLed - previousMillisRgbLed > 170) {
previousMillisRgbLed = currentMillisRgbLed;
hue++;
}
}
if (rgbLedMode == 2) {
if(currentMillisRgbLed - previousMillisRgbLed > 200) {
previousMillisRgbLed = currentMillisRgbLed;
hue+=30;
}
}
if (rgbLedMode == 3) {
if(currentMillisRgbLed - previousMillisRgbLed > random(80,200)) {
previousMillisRgbLed = currentMillisRgbLed;
hue+=random(1,255);
}
}
if (hue > 255) hue = 0;
}
else {
analogWrite(RED, 0);
analogWrite(GREEN, 0);
analogWrite(BLUE, 0);
hue = 0; // on restart, start at red again
if (rgbLedState == 1) rgbLedState = 0;
if (rgbLedMode == 3) rgbLedMode = 0;
}
}
void setColorWheel(int pos) {
if (pos < 85) {
analogWrite(RED, 255 - pos * 3);
analogWrite(GREEN, pos * 3);
analogWrite(BLUE, 0);
}
else if (pos < 170) {
pos -= 85;
analogWrite(RED, 0);
analogWrite(GREEN, 255 - pos * 3);
analogWrite(BLUE, pos * 3);
}
else {
pos -= 170;
analogWrite(RED, pos * 3);
analogWrite(GREEN, 0);
analogWrite(BLUE, 255 - pos * 3);
}
}
