rpi-led-control.js
function setBrightness(addr, intensity) {
	    if(addr<0 || addr>=maxDevices)
			return;
	 	if (typeof intensity == 'undefined') return; 
		
		intensity = constrain(intensity, 0, 15); 
	    	
		spiTransfer(addr, OP_INTENSITY,intensity);

	}
function setBrightness(addr, intensity) {
	    if(addr<0 || addr>=maxDevices)
			return;
	 	if (typeof intensity == 'undefined') return; 
		
		intensity = constrain(intensity, 0, 15); 
	    	
		spiTransfer(addr, OP_INTENSITY,intensity);

	}
sets the brightness of the LEDs, 0 to 15