Do something depend on Time-based - processing

Question

switch(mode) {
case 0:
if (millis() - timer >= 100) {
file.play();
timer = millis();
}
break;
case 1:
if (millis() - timer >= 1000) {
file1.play();
timer = millis();
}
break;
}
I want create a time-based program like a traffic light.
It will play the sound and last 3 seconds. After 3 second, it will turn into another sound and last 10 seconds.After 10 second, it will turn into first sound. And so on. How can i count the time for two case?

Answer 1

The conditions you use to compare millis() and timer look of in terms of logic. You might want to change the values to be 3 and 10 seconds (instead of 0.1 and 1 seconds)
It feels like you simply need 3 states:
It will play the sound and last 3 seconds.
After 3 second, it will turn into another sound and last 10 seconds
After 10 second, it will turn into first sound.
Something like this:
int mode;
int timer;
void setup() {
println("starting in 1st mode, seconds:",second());
}
void draw() {
switch(mode) {
case 0:
if (millis() - timer >= 3000) {
println("play sound 1, seconds:",second());
timer = millis();
mode = 1;//change to the state to the next one
}
break;
case 1:
if (millis() - timer >= 3000) {
print("play sound 2, seconds:",second());
timer = millis();
mode = 2;//go to next mode
}
break;
case 2:
if (millis() - timer >= 10000) {//wait 10s
println("\n10s passed, going to 1st mode, seconds:",second());
timer = millis();
mode = 0;//go to next mode, after 10s
}
break;
}
}
In terms of timing, you should have states looping in 3s, 3s and 10s increments.
I'm not 100% if sound will play as expected, but test with some println() commands first to see if what state happens at what time you expect it to, then simply trigger the sound you need in it's right place.
demo time:
var mode = 0;
var timer;
function setup() {
createCanvas(100,100);
timer = millis()
console.log("starting in 1st mode, seconds:",second());
}
function draw() {
background(255);
text("mode: " + mode + "\nseconds: " + second(),10,10);
switch(mode) {
case 0:
if (millis() - timer >= 3000) {
console.log("play sound 1, seconds:",second());
timer = millis();
mode = 1;//change to the state to the next one
}
break;
case 1:
if (millis() - timer >= 3000) {
console.log("play sound 2, seconds:",second());
timer = millis();
mode = 2;//go to next mode
}
break;
case 2:
if (millis() - timer >= 10000) {//wait 10s
console.log("10s passed, going to 1st mode, seconds:",second());
timer = millis();
mode = 0;//go to next mode, after 10s
}
break;
}
}
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