corrected an issue in loadData ISR that would cause a hang

Also updated Pixel example with Knight Rider Effect.
Testing on C3 seems to be working.  Must test on S2 and ESP32 next.

Other Examples/Pixel/Pixel.ino

@@ -34,8 +34,6 @@
 #include "HomeSpan.h"
 #include "extras/Pixel.h"                       // include the HomeSpan Pixel class
 
-CUSTOM_CHAR(Selector, 00000001-0001-0001-0001-46637266EA00, PR+PW+EV, UINT8, 1, 1, 5, false);      // create Custom Characteristic to "select" special effects via Eve App
-
 ///////////////////////////////
 
 struct Pixel_Light : Service::LightBulb {      // Addressable RGB Pixel
@@ -69,35 +67,56 @@ struct Pixel_Light : Service::LightBulb {      // Addressable RGB Pixel
 
 ///////////////////////////////
 
-struct Pixel_Strand : Service::LightBulb {      // Addressable RGB Pixel Strand of nPixel Pixels - allows for special effects controlled by custom characreristic
+struct Pixel_KnightRider : Service::LightBulb {      // Addressable RGB Pixel Strand of nPixel Pixels - Knight Rider Effect
  
   Characteristic::On power{0,true};
   Characteristic::Hue H{0,true};
-  Characteristic::Saturation S{0,true};
+  Characteristic::Saturation S{100,true};
-  Characteristic::Brightness V{100,true};
   Pixel *pixel; 
-  int nPixels;                                 // number of Pixels in Strand (default=1)
+  int nPixels;                                 
+  uint32_t *colors;
+  int phase=0;
+  int dir=1;
+  uint32_t alarmTime=0;
   
-  Pixel_Strand(int pin, int nPixels=1) : Service::LightBulb(){
+  Pixel_KnightRider(int pin, int nPixels) : Service::LightBulb(){
 
-    V.setRange(5,100,1);                      // sets the range of the Brightness to be from a min of 5%, to a max of 100%, in steps of 1%
     pixel=new Pixel(pin);                     // creates pixel LED on specified pin using default timing parameters suitable for most SK68xx LEDs
     this->nPixels=nPixels;                    // store number of Pixels in Strand
-    update();                                 // manually call update() to set pixel with restored initial values
+
+    colors=(uint32_t *)calloc(2*nPixels-1,sizeof(uint32_t));   // storage for dynamic pixel pattern
+    update();                                                  // manually call update() to set pixelk pattern with restored initial values
   }
 
   boolean update() override {
 
-    int p=power.getNewVal();
+    if(!power.getNewVal()){
+      pixel->setRGB(0,0,0,8);
+    } else {
+      float level=100;
+      for(int i=0;i<nPixels;i++,level/=2.5){
+        colors[nPixels+i-1]=pixel->getColorHSV(H.getNewVal<float>(),S.getNewVal<float>(),level);
+        colors[nPixels-i-1]=colors[nPixels+i-1];
+      }
+    }
     
-    float h=H.getNewVal<float>();                // range = [0,360]
-    float s=S.getNewVal<float>();                // range = [0,100]
-    float v=V.getNewVal<float>();                // range = [0,100]
-
-    pixel->setHSV(h*p, s*p, v*p, nPixels);       // sets all nPixels to HSV colors
-          
     return(true);  
   }
+
+  void loop() override {
+
+    if(millis()>alarmTime && power.getVal()){
+      alarmTime=millis()+80;
+      pixel->setColors(colors+phase,nPixels);
+      if(phase==7)
+        dir=-1;
+      else if(phase==0)
+        dir=1;
+      phase+=dir;
+    }
+    
+  }
+
 };
 
 ///////////////////////////////
@@ -134,10 +153,7 @@ void setup() {
   new Service::HAPProtocolInformation();
     new Characteristic::Version("1.1.0");
 
-  new Pixel_Strand(7,8);                         // create single Pixel attached to pin 8
+  new Pixel_KnightRider(1,8);               // create 8-Pixel Strand with Knight-Rider Effect attached to pin 1 
-  
-  (new Characteristic::Selector())->setUnit("")->setDescription("Color Effect")->setRange(1,5,1);
-  
 
 }
 

src/extras/Pixel.cpp

@@ -12,7 +12,11 @@ Pixel::Pixel(int pin){
   setTiming(0.32, 0.88, 0.64, 0.56, 80.0);    // set default timing parameters (suitable for most SK68 and WS28 RGB pixels)
 
   rmt_isr_register(loadData,NULL,0,NULL);               // set custom interrupt handler
-  rmt_set_tx_thr_intr_en(rf->getChannel(),true,8);      // enable threshold interrupt to trigger every 8 pulses
+  
+  rmt_set_tx_thr_intr_en(rf->getChannel(),false,8);     // disable threshold interrupt
+  txThrMask=RMT.int_ena.val;                            // save interrupt enable vector
+  rmt_set_tx_thr_intr_en(rf->getChannel(),true,8);      // enable threshold interrupt to trigger every 8 pulses 
+  txThrMask^=RMT.int_ena.val;                           // find bit that flipped and save as threshold mask for this channel 
 
   rmt_set_tx_intr_en(rf->getChannel(),false);           // disable end-of-transmission interrupt
   txEndMask=RMT.int_ena.val;                            // save interrupt enable vector
@@ -88,15 +92,15 @@ uint32_t Pixel::getColorHSV(float h, float s, float v){
 
 ///////////////////
 
-void Pixel::loadData(void *arg){
+void IRAM_ATTR Pixel::loadData(void *arg){
 
   if(RMT.int_st.val & status.px->txEndMask){
-    RMT.int_clr.val=~0;
+    RMT.int_clr.val=status.px->txEndMask;
     status.started=false;
     return;
   }
   
-  RMT.int_clr.val=~0;
+  RMT.int_clr.val=status.px->txThrMask;       // if loadData() is called and it is NOT because of an END interrupt (above) then must either be a pre-load, or a threshold trigger
 
   if(status.nPixels==0){
     RMTMEM.chan[status.px->rf->getChannel()].data32[status.iMem].val=0;

src/extras/Pixel.h

@@ -25,6 +25,7 @@ class Pixel {
     uint32_t pattern[2];           // storage for zero-bit and one-bit pulses
     uint32_t resetTime;            // minimum time (in usec) between pulse trains
     uint32_t txEndMask;            // mask for end-of-transmission interrupt
+    uint32_t txThrMask;            // mask for threshold interrupt
     
     const int memSize=sizeof(RMTMEM.chan[0].data32)/4;    // determine size (in pulses) of one channel
      

src/extras/extras.ino

@@ -82,9 +82,9 @@ struct Effect2 {
 #endif
 
 Pixel px2(2);
+Pixel px(PIN);
 Pixel px3(3);
 Pixel px4(4);
-Pixel px(PIN);
 Pixel px5(5);
 Pixel px6(6);
 Pixel px7(7);