{"id":2563,"date":"2022-11-01T14:40:21","date_gmt":"2022-11-01T14:40:21","guid":{"rendered":"https:\/\/ibex.tech\/resources\/?p=2563"},"modified":"2023-11-22T16:36:50","modified_gmt":"2023-11-22T16:36:50","slug":"usb-c-connection-to-older-usb-devices","status":"publish","type":"post","link":"https:\/\/ibex.tech\/resources\/geek-area\/communications\/usb\/usb-c\/usb-c-connection-to-older-usb-devices","title":{"rendered":"USB C connection to older USB devices"},"content":{"rendered":"\n<p>USB C uses a reversible connector, additional data pins and higher current capability. However, the pin usage from older USB will work just fine in many instances.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Simplest connection<\/h5>\n\n\n<pre>Required:<br>VBUS  5V input<br>GND   0V<br>D+    D+<br>D-    D-<br><br>Power signalling:<br>CC1 &amp; CC2 pin, each with a 5.1K resistor to GND. Indicates to the upstream port to provide 5V and up to 1.5A (it's a request by your device, it may not actually be able to supply that much current).<br><br>Optional:<br>Monitor CC and SBU pins to determine cable polarity (or leave disconnected)<\/pre>\n<\/p>\n\n\n<p>CC pins<\/p>\n\n\n\n<p>The CC1 and CC2 pins allow you to detect which orientation the cable has been inserted, because cables only have 1 wire providing the CC link. This means only 1 of the CC pins will be pulled by the remote devices resistors applied to the pin. At either end you can connect each CC pin to an AtoD and detect:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Which has been pulled = which orientation the connection is in<\/li>\n\n\n\n<li>What resistance the remote end has applied = its basic power specs<\/li>\n<\/ul>\n\n\n\n<p>If you don&#8217;t care about connector orientation, which will be the case if you&#8217;re just providing a basic D+ and D- connection to both of the sets D- and D+ pins, then you can link the two CC pins and apply just the one resistor and save yourself an extra AtoD input being used on your processor.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Resistor values<\/h5>\n\n\n\n<p>A DFP device (Downwards facing port \/ Host) either has its CC pins linked (if it doesn&#8217;t care about connector orientation) or has a resistor on each. The resistor is the Rp resistor, has a standard value (500mA\/900mA current capability) of 56K when pulled up to +5V, or 36K if pulled to 3V3 (e.g. for a 3V3 CPU AtoD input). However, it can have different values for different current availability advertising and be pulled to different voltages.<\/p>\n\n\n\n<p>A UFP (Upwards facing port \/ Device)  either has its CC pins linked (if it doesn&#8217;t care about connector orientation) or has a resistor on each. The resistor is the Rd resistor, each has a value of 5K1 and is pulling down to 0V.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Good resources<\/h4>\n\n\n\n<p><a href=\"https:\/\/microchipdeveloper.com\/usb:tc-pins\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/microchipdeveloper.com\/usb:tc-pins<\/a><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Adapter PCBs<\/h4>\n\n\n\n<p><a href=\"https:\/\/www.adafruit.com\/product\/4090\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/www.adafruit.com\/product\/4090<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>USB C uses a reversible connector, additional data pins and higher current capability. However, the pin usage from older USB will work just fine in many instances. Simplest connection Required:VBUS 5V inputGND 0VD+ D+D- D-Power signalling:CC1 &amp; CC2 pin, each with a 5.1K resistor to GND. Indicates to the upstream port to provide 5V and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[135],"tags":[],"class_list":["post-2563","post","type-post","status-publish","format-standard","hentry","category-usb-c"],"_links":{"self":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/2563","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/comments?post=2563"}],"version-history":[{"count":13,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/2563\/revisions"}],"predecessor-version":[{"id":2760,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/posts\/2563\/revisions\/2760"}],"wp:attachment":[{"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/media?parent=2563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/categories?post=2563"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibex.tech\/resources\/wp-json\/wp\/v2\/tags?post=2563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}