Multiple buttons activating different methods for an LED strip

Question

I am trying to use different buttons to activate different methods for an LED strip. However, when one button is pressed after another has been pressed, I want it to interrupt the first buttons method and begin the second. For example: one button sends a rainbow pattern through the LED strip when pressed, however, while it is cycling through the rainbow, the second button is pressed which sends a white cycle through the LED strip. There will be 24 buttons total. I have gotten this to work with 2 buttons but am having trouble getting it to work for a third. The code is below:

 void loop(){
 if (digitalRead(inPin(1)) == HIGH && lastState == LOW){//if button has just been pressed
 stopCycle();
 theaterChaseRainbow(50);
 }
 if (digitalRead(inPin(2)) == HIGH){
 stopCycle();
 theaterChase(strip.Color(127, 127, 127), 50); // White
 }
 if (digitalRead(inPin(3)) == HIGH){
 stopCycle();
 rainbowCycle(0); 
 }
 }
 //Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
 for (int j=0; j<100; j++) { //do 100 cycles of chasing
 if (digitalRead (inPin(1)) == LOW) { //checks that other button(s) have not been pressed
 if (digitalRead (inPin(3) == LOW)){
 for (int q=0; q < 3; q++) {
 for (int i=0; i < strip.numPixels(); i=i+3) {
 strip.setPixelColor(i+q, c); //turn every third pixel on
 }
 strip.show();
 delay(wait);
 for (int i=0; i < strip.numPixels(); i=i+3) {
 strip.setPixelColor(i+q, 0); //turn every third pixel off
 }
 }
 }
 }
 }
}
void rainbow(uint8_t wait) {
 int i, j;
 for (j=0; j < 384; j++) { 
 if (digitalRead (inPin(2)) == LOW) { // 3 cycles of all 384 colors in the wheel
 if (digitalRead (inPin(3) == LOW)){
 for (i=0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, Wheel( (i + j) % 384));
 } 
 strip.show(); // write all the pixels out
 delay(wait);
 }
 } 
 }
}
uint32_t Wheel(uint16_t WheelPos)
{
 byte r, g, b;
 switch(WheelPos / 128)
 {
 case 0:
 r = 127 - WheelPos % 128; //Red down
 g = WheelPos % 128; // Green up
 b = 0; //blue off
 break; 
 case 1:
 g = 127 - WheelPos % 128; //green down
 b = WheelPos % 128; //blue up
 r = 0; //red off
 break; 
 case 2:
 b = 127 - WheelPos % 128; //blue down 
 r = WheelPos % 128; //red up
 g = 0; //green off
 break; 
 }
 return(strip.Color(r,g,b));
}
void rainbowCycle(uint8_t wait) {
 uint16_t i, j;
 for (j=0; j < 384 * 5; j++) { // 5 cycles of all 384 colors in the wheel
 if (inPin(1) == LOW) {
 if (inPin(2) == LOW) {
 for (i=0; i < strip.numPixels(); i++) {
 // tricky math! we use each pixel as a fraction of the full 384-color wheel
 // (thats the i / strip.numPixels() part)
 // Then add in j which makes the colors go around per pixel
 // the % 384 is to make the wheel cycle around
 strip.setPixelColor(i, Wheel( ((i * 384 / strip.numPixels()) + j) % 384) );
 } 
 strip.show(); // write all the pixels out
 delay(wait);
 }
 }
 }
}
void stopCycle(){
 int i;
 for (i=0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, 0);
 } 
 strip.show(); // write all the pixels out
}

Answer 1

Inside each inner loop, just test the switches and return if they are pressed.

eg.

//Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
 for (int j=0; j<100; j++) { //do 100 cycles of chasing
 for (int q=0; q < 3; q++) {
 for (int i=0; i < strip.numPixels(); i=i+3)
 {
 strip.setPixelColor(i+q, c); //turn every third pixel on
 }
 strip.show();
 delay(wait);
 // give up if switches pressed
 if (digitalRead (inPin(1)) == HIGH || 
 digitalRead (inPin(2)) == HIGH ||
 digitalRead (inPin(3)) == HIGH )
 return;
 for (int i=0; i < strip.numPixels(); i=i+3) {
 strip.setPixelColor(i+q, 0); //turn every third pixel off
 }
 }
 }
}

---

am having trouble getting it to work for a third

If that doesn't help please explain the nature of this "trouble".

---

You may need to debounce the switch presses. And you may need to wait for them to release the switch, eg.

 if (digitalRead(inPin(1)) == HIGH && lastState == LOW){//if button has just been pressed
 stopCycle();
 while (digitalRead(inPin(1)) == HIGH)
 { } // wait for switch release
 delay (10); // debounce
 theaterChaseRainbow(50);
 }

• Jet Propelled Insectivore: This is an excellent solution but is there a way to move the return statement to the loop? This way, I could call theatreChase multiple times with different buttons at different paramenters.
• Nick Gammon: I'm not sure what you mean by "move the return statement to the loop". Can you elaborate?

Answer 2

I would normally do this (pseudocode):

void loop() {
 static state=state_off;
 if (button_1_pushed) {
 state=state_1;
 } elseif (button_2_pushed) {
 state=state_2;
 }
 if (state==state_off) {
 turn_all_leds_off();
 } elseif (state==state_2) {
 shownextframe_rainbow();
 } elseif (state==state_2) {
 shownextframe_chaser();
 }
 delay(1);
}

In shownextframe_chaser/shownextframe_rainbow, I would probably work out what should be shown based on the current millis() - e.g. if your chaser has 10 lights, and you want it to pulse over 1 second, then each led should be on for 100 millis, so at any instant, the led that should be on is (millis()/100)%10 (assuming the led's are numbered for 0 to 9).