I noticed that the SparkFun product has export restrictions, which seemed funny.<p>I dug up this text on their site: <a href="https:&#x2F;&#x2F;www.sparkfun.com&#x2F;support#IntExportRestrictions" rel="nofollow">https:&#x2F;&#x2F;www.sparkfun.com&#x2F;support#IntExportRestrictions</a>, which says:<p><i>[...] These are products designed for civilian use, but that could be used for devious purposes in the wrong hands. [...] </i><p>So, I guess that tells me there are weapons or other &quot;dangerous&quot; machines that have UARTs. Who would have thought that, huh? :| Really dubious restriction, but I guess they don&#x27;t have a choice.