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  • _bufferSize is the length of the graphics buffer, in my case 5808 bytes (176*264/8).

    So the code is this (inside a lot more code):

    IL91874.prototype.grfxBlackWhite = function () {  
      var _display = this;
      var g = Graphics.createArrayBuffer(
                this.display.displaySizeX,
                this.display.displaySizeY,
                this.display.bpp,
                {msb: true}
              );
      g.clear = function(clearColor){    
        new Uint8Array(this.buffer).fill(clearColor)­;print(this);
      };
      g.flip = function(callback){     
        //this does not work
        _display.wCmd(_display.display.CMD.DATA_­START_TRANSMISSION_1);
        _display.wData(this.buffer); 
        
        //this works
        //_display.wCmd(_display.display.CMD.DAT­A_START_TRANSMISSION_1);
        //for (let i=0;i<this.buffer.length;i++) _display.wData(this.buffer[i]);
         
        _display.waitBusy(callback);
      };
      return g;
    };
    IL91874.prototype.wCmd = function (command) {
      digitalWrite(this.dcPin, 0);
      this.spi.write(command, this.cs1Pin);  
    };
    IL91874.prototype.wData = function (data) {
     digitalWrite(this.dcPin, 1);
     this.spi.write(data, this.cs1Pin);
    };
    

    So what it does is, when flip is called, transmit the buffer data to the papers ram.

    It is actually only a modification of the SSD1606 module code. In there the flip function it does exactly the same: transmit the buffer data via SPI as an Uint8Array (as I just learned, more a view to the buffer?).
    Maybe that's the problem? I'm assuming that what works in the example code also would work in my case.

    Otherwise I can only think of a problem in transmitting speed. I played around with the SPI baud rate (set it lower) but to no avail.

    I mean, the code does work, but writing 2 buffers (one for red, one for black) takes about 3.5s each + the 15s update cycle of the paper. I think there is potential for speeding up things.

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