{
        <span class="kw">loop</span> {
            <span class="kw">let</span> <span class="ident">byte</span> <span class="op">=</span> <span class="macro">await</span><span class="macro">!</span>(<span class="ident">serial</span>.<span class="ident">read</span>()).<span class="ident">unwrap</span>();
            <span class="macro">await</span><span class="macro">!</span>(<span class="ident">serial</span>.<span class="ident">write</span>(<span class="ident">byte</span>)).<span class="ident">unwrap</span