very slow frame rate for ESP & APA102

[mkeyno]

hi @focalintent , I've tried to implement my POV project with ESP, but frame rate is so slow for 144 APA102 pixel,my idea is to read pixel data from SPIFF file without closing it , but result beyond my expectation very slow even with 160Mhz clock following is the serial output and loop code

i=0 New Image=1.bin duration=4 [frame]1076598 [frame]1043446 [frame]1044003 [frame]1043555 i=1 New Image=2.bin duration=4 [frame]1057822 [frame]1052909 [frame]1052453 i=2 New Image=3.bin duration=4 [frame]1067164 [frame]1042669 [frame]1043549 [frame]1042468 i=3 New Image=4.bin duration=4 [frame]1059210 [frame]1044297 [frame]1044701 [frame]1044550 i=4 New Image=5.bin duration=4 [frame]1059668 [frame]1042478 [frame]1043678 [frame]1043824 i=5 New Image= duration=0 FILE NOT OPEN i=0 New Image=1.bin duration=4 [frame]1075868 [frame]1044087 [frame]1044103 [frame]1044578 i=1 New Image=2.bin duration=4 [frame]1059307 [frame]1052474 [frame]1052181 i=2 New Image=3.bin duration=4 [frame]1067527 [frame]1042757 [frame]1042843 [frame]1043076 i=3 New Image=4.bin duration=4 [frame]1058051 [frame]1045418 [frame]1046048 [frame]1045034 i=4 New Image=5.bin duration=4 [frame]1059883 [frame]1043249 [frame]1043334 [frame]1043710 i=5 New Image= duration=0 FILE NOT OPEN i=0 New Image=1.bin duration=4

loop code

void loop() 
{

 if(!SHOW)   server.handleClient();  
  webSocket.loop();

  if(SHOW)
      {
        if( (millis()- OpenlastTime) > DURATION[image_index]*1000L )
        {
          FILe.close();
          image_index++; 
          if(image_index>IMAGE_NUM)    image_index=0;

           Serial.print(F(" i="));  Serial.print(image_index); 
          Serial.print(F(" New Image="));  Serial.print(IMAGES[image_index]);
          Serial.print(F(" duration="));  Serial.println(DURATION[image_index]);

           FILe=SPIFFS.open("/SHOW/"+IMAGES[image_index], "r");
          if(!FILe) Serial.println("FILE NOT OPEN");
          OpenlastTime=millis();
        }
        if(!Start_new_round && (micros()-lastLineShow)> lineInterval)
                          {
                          int i=0,j=0;
                          byte rgb=0,r,g,b; 
                          while(FILe.available()&& i< (NUM_LEDS*3))
                                                                    {
                                                                    byte c=FILe.read();
                                                                         if(rgb==0) r=byte(c);
                                                                    else if(rgb==1) g=byte(c);
                                                                    else if(rgb==2) b=byte(c);
                                                                    else           { rgb=0;
                                                                                     leds[j] = CRGB(r,g,b);
                                                                                     j++; 
                                                                                     }
                                                                    rgb++;            
                                                                    i++;
                                                                    }
                          FastLED.show(); lastLineShow=micros();                          
                          Current_imageLine++;                                        
                          }
       FastLED.show(); lastLineShow=micros(); }
          if(Current_imageLine >= IMAGES_LINES)   
          { 
            Serial.print("[frame]"); Serial.println((micros()-lastFrameShow));
            Current_imageLine = 0;
            lastFrameShow=micros(); 
            Start_new_round=false; 
            FILe.close();
            FILe=SPIFFS.open("/SHOW/"+IMAGES[image_index], "r");
           } 

      }
}

[kriegsman]

Hi, @mkeyno. Looks like it'll be a cool project once you get the I/O speed worked out.

Could you take this question over to our Google Plus discussion group? Here's a link: http://fastled.io/+ We like to reserve github tickets for actual bugs in the FastLED library itself, and we use the Google Plus discussion group for general troubleshooting and performance help.

[focalintent]

Ok, a couple of things - first of all, you're calling FastLED.show() way too often. Instead of just calling it every time you read a new line in, you're reading it every time through the loop (or you pasted your code in badly).

The second is the way that you're reading data in, one byte at a time, is going to be wildly inefficient - you can just read the bytes directly into the CRGB array:

  if(!Start_new_round && (micros()-lastLineShow)> lineInterval) {
    int i = 0; 

    while( (i < NUM_LEDS*3) && FIle.available()) { 
      i += FIle.readBytes( ((byte*)leds) + i, (NUM_LEDS*3)-i);
    }
    FastLED.show();
    lastLineShow(micros());
  } 

Also, to get a better feel for your timing numbers, it'd be useful to know how many lines of output are being written in the ~1s/"frame" that you're running.

Also, instead of closing/re-opening the file, instead use the seek method to jump back to the beginning of it - FIle.seek(0, SeekSet);

[kriegsman]

Thanks, Dan. Yeah, I think this is a "performance optimization" conversation; let's take it over to Google Plus. I'm closing the ticket here.

Shortcut to G+ group: http://fastled.io/+

[focalintent]

As mark said - we prefer for discussions and requests for help to be kept to the g+ group - not here. (Its even worse when people hijack a ticket for one thing with a request for help with something entirely different)

The code you wrote to read a single byte and put it into an array means that for every byte you are doing multiple function calls, at least 5 comparisons, etc... That's a lot of wasted time there - calling readBytes allows the underlying code to do more interesting things with larger transfers not to mention completely bypassing the chain of extra comparisons you have in there.

If you want to discuss this more, please take it to the g+ group. I'm starting to lock issues/threads that either shouldn't be here or get derailed off topic.