Arduino ignoring serial interrupts when using FastLED - arduino

Question

I have tried several different methods found around the internet, however none of them seem to work. This code works for cases 0-2 but when it goes into case 3 which is the rainbow chase loop, the pressing of the button does not interrupt the loop and move the counter forward. I'm assuming, as usual, I'm missing something stupid so many thanks in advance.
#define FASTLED_ALLOW_INTERRUPTS 1
#define FASTLED_INTERRUPT_RETRY_COUNT 1
#include <FastLED.h>
#define AnalogIn A0
#define SwIn 2
#define LED_Out 12
#define NUM_LEDS 5
int pushCounterz = 0;
volatile int buttonState; // Set volatile for interrupt DO NOT SHAKE!
int lastButtonState;
CRGB leds[NUM_LEDS];
void setup() {
// put your setup code here, to run once:
FastLED.setMaxRefreshRate(250);
FastLED.addLeds<WS2812, LED_Out, GRB>(leds, NUM_LEDS);
pinMode(SwIn, INPUT);
pinMode(LED_Out, OUTPUT);
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 255, 0, 255 );
}
FastLED.show();
delay(120);
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 0 );
}
FastLED.show();
Serial.begin(115200);
Serial.println(pushCounterz);
lastButtonState = digitalRead(SwIn); // Set the button state to the startup state
attachInterrupt((SwIn-2), button_ISR, CHANGE); // Set SwIn button as an interrupt pin // Change to Low???
}
void loop() {
if (pushCounterz != 3) {
FastLED.show();
}
Serial.println(pushCounterz);
delay(120);
}
void button_ISR () {
buttonState = digitalRead(SwIn);
digitalWrite(13, buttonState);
if (buttonState == LOW && buttonState != lastButtonState) {
if (pushCounterz > 3) {
//Serial.println("Reset to 0: ");
pushCounterz = 0;
} else {
pushCounterz = pushCounterz + 1;
//Serial.println("Incerment");
}
//Serial.println(pushCounterz);
switch (pushCounterz) {
case 0:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB (255, 0, 0);
}
break;
case 1:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 255, 0);
}
break;
case 2:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 255);
}
break;
case 3:
theaterChaseRainbow(1,50);
break;
default:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 0);
}
break;
}
}
lastButtonState = buttonState;
}
// Theater-style crawling lights with rainbow effect
void theaterChaseRainbow(int cycles, int speed) { // TODO direction, duration
for (int j = 0; j < 256 * cycles; j++) { // cycle all 256 colors in the wheel
for (int q = 0; q < 3; q++) {
for (int i = 0; i < NUM_LEDS; i = i + 3) {
int pos = i + q;
leds[pos] = Wheel( (i + j) % 255); //turn every third pixel on
}
FastLED.show();
delay(speed);
for (int i = 0; i < NUM_LEDS; i = i + 3) {
leds[i + q] = CRGB::Black; //turn every third pixel off
}
}
}
}
CRGB Wheel(byte WheelPos) {
if (WheelPos < 85) {
return CRGB(WheelPos * 3, 255 - WheelPos * 3, 0);
}
else if (WheelPos < 170) {
WheelPos -= 85;
return CRGB(255 - WheelPos * 3, 0, WheelPos * 3);
}
else {
WheelPos -= 170;
return CRGB(0, WheelPos * 3, 255 - WheelPos * 3);
}
}

Answer 1

Your issue is not that the button is not changing the value, but rather your code has no exit point if it does; the button will change the value, but nothing in theaterChaseRainbow tells it to stop.
Simply add a check in the method to return out if the button state changes:
// Theater-style crawling lights with rainbow effect
void theaterChaseRainbow(int cycles, int speed) { // TODO direction, duration
for (int j = 0; j < 256 * cycles; j++) { // cycle all 256 colors in the wheel
for (int q = 0; q < 3; q++) {
for (int i = 0; i < NUM_LEDS; i = i + 3) {
int pos = i + q;
leds[pos] = Wheel( (i + j) % 255); //turn every third pixel on
}
FastLED.show();
if (pushCounterz != 3) return; //ADDED THIS HERE*****
delay(speed);
for (int i = 0; i < NUM_LEDS; i = i + 3) {
leds[i + q] = CRGB::Black; //turn every third pixel off
}
}
}
}
In addition, I would suggest simplifying your ISR to just increment the button and not have it handle the logic of the program as well. That should either be contained in the loop method or called from the loop method. This should make for some cleaner and less confusing code, as the ISR's job is simply to adjust the value of the button counter, and the loops job is to deal with the state that the program is currently in.

Answer 2

Also - you can't allow interrupts on AVR, or rather I should say it does nothing. I should put in a warning message when that's happening - AVR/arduino's ISR handling is so slow that even the clock tick ISR would be enough to disrupt writing out WS2812 data (resulting in FastLED cutting the frame off) so I yanked that code out of the avr WS2812 asm implementation. Most arm and esp platforms that FastLED supports do allow for interrupt handling to occur during in the small window between writing out each led's data - courtesy of their higher clock speeds.
If you're using an ARM or ESP based platform, then feel free to ignore this comment (mostly putting it here so folks who stumble on this question in a good search know what's up).

Answer 3

As a reference, the working code with the ISR cleanup. (mind you there is still some serial debugging code in there as I have more work to do with brightness etc)
#define FASTLED_ALLOW_INTERRUPTS 1
#define FASTLED_INTERRUPT_RETRY_COUNT 1
#include <FastLED.h>
#define AnalogIn A0
#define SwIn 2
#define LED_Out 12
#define NUM_LEDS 5
int pushCounterz = 4; // 4 = off
volatile int buttonState; // Set volatile for interrupt DO NOT SHAKE!
int lastButtonState;
CRGB leds[NUM_LEDS];
void setup() {
// put your setup code here, to run once:
FastLED.setMaxRefreshRate(250);
FastLED.addLeds<WS2812, LED_Out, GRB>(leds, NUM_LEDS);
pinMode(SwIn, INPUT);
pinMode(LED_Out, OUTPUT);
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 255, 0, 255 );
}
FastLED.show();
delay(120);
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 0 );
}
FastLED.show();
Serial.begin(19200);
Serial.println(pushCounterz);
lastButtonState = digitalRead(SwIn); // Set the button state to the startup state
attachInterrupt((SwIn-2), button_ISR, LOW); // Set SwIn button as an interrupt pin // Change to Low???
}
void loop() {
// if (pushCounterz != 3) {
//FastLED.show();
//Serial.println(pushCounterz);
// }
//delay(20);
switch (pushCounterz) {
case 0:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB (255, 0, 0);
}
FastLED.show();
break;
case 1:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 255, 0);
}
FastLED.show();
break;
case 2:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 255);
}
FastLED.show();
break;
case 3:
theaterChaseRainbow(1,50);
break;
default:
for (int i = 0; i < NUM_LEDS; i++) {
leds[i] = CRGB ( 0, 0, 0);
}
FastLED.show();
break;
}
}
void button_ISR () {
buttonState = digitalRead(SwIn);
//digitalWrite(13, buttonState);
if (buttonState == LOW && buttonState != lastButtonState) {
if (pushCounterz > 3 || pushCounterz < 0) {
Serial.println("Reset to 0: ");
pushCounterz = 0;
} else {
pushCounterz = pushCounterz + 1;
Serial.println("Incerment");
}
Serial.println(pushCounterz);
}
lastButtonState = buttonState;
}
// Theater-style crawling lights with rainbow effect
void theaterChaseRainbow(int cycles, int speed) { // TODO direction, duration
for (int j = 0; j < 256 * cycles; j++) { // cycle all 256 colors in the wheel
for (int q = 0; q < 3; q++) {
for (int i = 0; i < NUM_LEDS; i = i + 3) {
int pos = i + q;
leds[pos] = Wheel( (i + j) % 255); //turn every third pixel on
}
FastLED.show();
if (pushCounterz != 3) return;
delay(speed);
for (int i = 0; i < NUM_LEDS; i = i + 3) {
leds[i + q] = CRGB::Black; //turn every third pixel off
}
}
}
}
CRGB Wheel(byte WheelPos) {
if (WheelPos < 85) {
return CRGB(WheelPos * 3, 255 - WheelPos * 3, 0);
}
else if (WheelPos < 170) {
WheelPos -= 85;
return CRGB(255 - WheelPos * 3, 0, WheelPos * 3);
}
else {
WheelPos -= 170;
return CRGB(0, WheelPos * 3, 255 - WheelPos * 3);
}
}