Joli\ArDrone\Navdata\Frame::getFrameOptions PHP Method

    public function getFrameOptions()
    {
        $isChecksum = false;
        while (!$isChecksum) {
            $idOption = hexdec($this->buffer->getUint16LE());
            $nameOption = Option::$optionIds[$idOption];
            $sizeOption = $this->buffer->getUint16LE();
            if ($nameOption === 'checksum') {
                $isChecksum = true;
                $expectedChecksum = 0;
                $checksum = $this->buffer->getUint32LE();
                $data = $this->buffer->getData();
                for ($i = 0; $i < $this->buffer->getLength() - $sizeOption; ++$i) {
                    $expectedChecksum = $expectedChecksum + hexdec(bin2hex($data[$i]));
                }
                $expectedChecksum = dechex($expectedChecksum);
                if ($checksum !== $expectedChecksum) {
                    throw new \Exception('Invalid checksum');
                }
            }
            $option = new Option($idOption, $this->buffer);
            $this->options[$option->getName()] = $option;
        }
    }