rpi-led-control.js
function setScanLimit(addr, limit) {
	    if(addr<0 || addr>=maxDevices)
			return;

		//console.log("OP_SCANLIMIT");
	    if(limit>=0 && limit<8)
	    	spiTransfer(addr, OP_SCANLIMIT,limit);
	}
function setScanLimit(addr, limit) {
	    if(addr<0 || addr>=maxDevices)
			return;

		//console.log("OP_SCANLIMIT");
	    if(limit>=0 && limit<8)
	    	spiTransfer(addr, OP_SCANLIMIT,limit);
	}
sets the number of pixels per row, pretty much always 8 for most devices.