Smooth sailing with most of the exercises, but tried to write code from scratch out of the “getting started with Arduino” book (Example 5-2. Sketch to change the brightness as you hold the button) and totally failed to get off the ground. Code and board image are below.. Would love some help in figuring what I’ve done wrong.
Digital Input – Original
Digital Input – Reversed
Serial monitor
Analog Input
Example 5-2. Sketch to change the brightness as you hold the button
Board Layout
Unsuccessful Code Attempt
/*
Fade with button Adjust (test coding from Bart)
*/
const int LED = 9; // the pin for the LED
const int BUTTON = 7; //input pin of the pushbutton
int val = 0; // stores the state of the input pin
int old_val = 0; // stores the state of the input pin
int state = 0; // 0 = LED off while 1 = LED on
int brightness = 128; // stores the brightness value
unsigned long startTime = 0; // when did we begin pressing?
void setup() {
pinMode(LED, OUTPUT); // tell Arduino LED is an output
pinMode(BUTTON, INPUT); //and BUTTON is an input
}
void loop() {
val - digitalRead(BUTTON); // read input value and store it
// check if there was a transition
if ((val == HIGH) && (old_val == LOW)) {
state = 1 - state; //change the state from off to on or vise-versa
startTime = millis(); // millis() is the arduino clock
// it returns hom many milliseconds havbe passed since the board has been reset
// (this line remembers when the button was last pressed)
delay (10);
}
// check whether the button is being held down
if ((val == HIGH) && (old_val == HIGH)) {
// if the burron is held for more than 500ms.
if (state == 1 && (millis() - startTime) > 500) {
brightness++; //increment brightness by 1
delay(10); // delay to avoid brightness going up too fast
if (brightness > 255) { // 255 is the max brightness
brightness = 0; // if we go over 255 let's go back to 0
}
}
}
old_val = val; // val is now old, let's store it
if (state == 1) {
analogWrite(LED, brightness); // turn LED ON at the current brightness level
} else {
analogWrite(LED, 0); // turn LED OFF
}
}