bad at computer

A couple months ago, I was messing with one of my kid’s toys: it was a small, cheap kaleidoscope shaped like a camera, made of wood and plastic. Pressing the shutter button made it chirp and flash as if a photo were being taken.

After a while it stopped working, so I assumed I needed to replace the battery. But when I tried prying out the button cells, I cracked the wood and broke the housing. Instead of trying to repair the wood, I decided to take apart the whole contraption and salvage the LED, sound chip, and some electronic parts to use with my breadboard.

I hadn’t picked up the breadboard for at least a year, and I thought I could use my ‘new’ LED in a project to absolve my guilt at having broken a perfectly fine toy.

This mini project was focused on getting a row of LEDs to blink. Once that was working, I added a button switch that let me change the speed of the blinks.

A basic overview of my setup:

• I’m coding using the PlatformIO extension in Visual Studio Code.
• The breadboard’s chip is the WeMos D1 Mini.
• The sketch uses a few LEDs, resistors for protection, and a switch.
• Pressing the switch changes the speed of the blinking LEDs.

Code goes here for now.

#include <ESP8266WiFi.h>

#define PIN_LED_GRN D1
#define PIN_LED_RED D2
#define PIN_LED_CLR D3
#define PIN_LED_BLU D4
#define PIN_LED_YEL D5
#define PIN_BUTTON  D6

#define LED_OFF     0
#define LED_ON      255

#define SPEED_MIN   50
#define SPEED_MAX   1000

long pastTime = 0;
long speed = SPEED_MAX;

boolean buttonPressed = false;

enum LedState {
  BLU,
  GRN,
  RED,
  YEL,
  CLR
};

LedState currentLedState = BLU;

// function declarations:
void handleButtonPress();

void setup(void) {

  Serial.begin(115200);

  Serial.println();
  Serial.println("Booting Sketch...");
  attachInterrupt(digitalPinToInterrupt(PIN_BUTTON), handleButtonPress, FALLING);

  pinMode(PIN_LED_BLU, OUTPUT);
  pinMode(PIN_LED_GRN, OUTPUT);
  pinMode(PIN_LED_RED, OUTPUT);
  pinMode(PIN_LED_YEL, OUTPUT);
  pinMode(PIN_LED_CLR, OUTPUT);
  pinMode(PIN_BUTTON, INPUT_PULLUP);

  digitalWrite(PIN_LED_BLU, LED_OFF);
  digitalWrite(PIN_LED_GRN, LED_OFF);
  digitalWrite(PIN_LED_RED, LED_ON);
  digitalWrite(PIN_LED_YEL, LED_OFF);
  digitalWrite(PIN_LED_CLR, LED_OFF);

}


void loop(void) {
  // main code here, to run repeatedly:

  if(buttonPressed) {
    handleButtonPress();
  }

  if(millis() - pastTime >= speed) {
      switch(currentLedState) {
        case BLU:
          digitalWrite(PIN_LED_BLU, LED_ON);   // inverted for D4
          digitalWrite(PIN_LED_GRN, LED_ON);
          currentLedState = GRN;
          break;
        case GRN:
          digitalWrite(PIN_LED_GRN, LED_OFF);
          digitalWrite(PIN_LED_RED, LED_ON);
          currentLedState = RED;
          break;
        case RED:
          digitalWrite(PIN_LED_RED, LED_OFF);
          digitalWrite(PIN_LED_YEL, LED_ON);
          currentLedState = YEL;
          break;
        case YEL:
          digitalWrite(PIN_LED_YEL, LED_OFF);
          digitalWrite(PIN_LED_CLR, LED_ON);
          currentLedState = CLR;
          break;  
        case CLR:
          digitalWrite(PIN_LED_CLR, LED_OFF);    
          digitalWrite(PIN_LED_BLU, LED_OFF);   // inverted for D4
          currentLedState = BLU;
          break;
      }
      pastTime = millis();
    }
}

// function definitions:
void IRAM_ATTR handleButtonPress() {
  speed = speed / 2;
  if(speed < SPEED_MIN) {
    speed = SPEED_MAX;
  }
}