="ident">timer</span>::<span class="ident">CountDown</span>,
    <span class="ident">S</span>: <span class="ident">hal</span>::<span class="ident">serial</span>::<span class="ident">Read</span><span class="op">&lt;</span><span class="ident">u8</span><span class="op">&gt;</span>,
{
    <span class="ident">timer</span>.<span class="ident">start</span>(<span class="ident">timeout</span>);

    <span class="kw">loop</span> {
        <span class="kw">match</span> <span class="ident">serial</span>.<span class="id