{"id":83,"date":"2016-05-03T18:20:03","date_gmt":"2016-05-03T22:20:03","guid":{"rendered":"http:\/\/www.hackspot.net\/CircleBlog\/?p=83"},"modified":"2016-05-03T18:20:03","modified_gmt":"2016-05-03T22:20:03","slug":"adding-a-serial-port-to-the-circle","status":"publish","type":"post","link":"http:\/\/www.hackspot.net\/CircleBlog\/2016\/05\/03\/adding-a-serial-port-to-the-circle\/","title":{"rendered":"Adding a serial port to the Circle"},"content":{"rendered":"<p>The Circle device has a serial port (TTL levels). \u00a0It is located (3 pads) on the &#8220;bottom board&#8221; (the board that rests on the bottom of the case, with the USB power connector and LED).<\/p>\n<p>Here&#8217;s a photo showing my board with a TTL serial cable connected (I had a 3-pin header soldered onto the pads):<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-82\" src=\"http:\/\/www.hackspot.net\/CircleBlog\/wp-content\/uploads\/2016\/05\/IMG_7594-e1462313238806.jpg\" alt=\"IMG_7594\" width=\"4032\" height=\"3024\" \/><\/p>\n<p>Looking at the connections on the photo, you can see that there are 3 wires from my TTL serial adapter connected to the 3 pins on the header (3 pads on the board).<\/p>\n<p>The signals are (in order, from top):<\/p>\n<pre>TX - transmitted data (from the Circle to the PC) (white wire in photo)\r\nRX - received data (from the PC to the Circle) (green wire in photo)\r\nGND - Ground (black wire in photo)<\/pre>\n<p><strong>Remember<\/strong>: these are TTL-level signals (0-3.3V). \u00a0They are NOT RS-232 +\/-12V signals! \u00a0Connecting RS-232 signals to these pads could <strong><em>destroy<\/em><\/strong> the Circle&#8217;s serial port (or the entire board)!<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Circle device has a serial port (TTL levels). \u00a0It is located (3 pads) on the &#8220;bottom board&#8221; (the board that rests on the bottom of the case, with the USB power connector and LED). Here&#8217;s a photo showing my board with a TTL serial cable connected (I had a 3-pin header soldered onto the &hellip; <a href=\"http:\/\/www.hackspot.net\/CircleBlog\/2016\/05\/03\/adding-a-serial-port-to-the-circle\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Adding a serial port to the Circle&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/posts\/83"}],"collection":[{"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/comments?post=83"}],"version-history":[{"count":5,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/posts\/83\/revisions"}],"predecessor-version":[{"id":88,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/posts\/83\/revisions\/88"}],"wp:attachment":[{"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/media?parent=83"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/categories?post=83"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.hackspot.net\/CircleBlog\/wp-json\/wp\/v2\/tags?post=83"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}