{"id":319066,"date":"2025-12-01T20:14:08","date_gmt":"2025-12-01T20:14:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/319066\/"},"modified":"2025-12-01T20:14:08","modified_gmt":"2025-12-01T20:14:08","slug":"hari-r-s-graytimer-is-a-simple-epaper-watch-built-from-a-seeed-studio-xiao-nrf52840","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/319066\/","title":{"rendered":"Hari R.&#8217;s Graytimer Is a Simple ePaper Watch Built From a Seeed Studio XIAO nRF52840"},"content":{"rendered":"<p class=\"hckui__typography__bodyL\">Maker Hari R. has designed a 3D-printable ePaper watch that, unlike its arguably more polished rivals, doesn&#8217;t require a custom PCB \u2014 instead simply packing an off-the-shelf Seeed Studio XIAO nRF52840 board and compatible display in a 3D-printed housing.<\/p>\n<p class=\"hckui__typography__bodyL\">&#8220;There are plenty of better built [watches],&#8221; Hari R. admits of the functional if somewhat-bulky design of his own wrist-worn gadget, &#8220;but those require PCBs to be fabricated. A PCB is better because the watch can be compact while we add features like buttons and all that. But I wanted to do try something simple, just with soldering. No flashy features. Just shows time, changes watchface every 10 mins. Fun.&#8221;<\/p>\n<p>Graytimer is a simple ePaper watch powered by a XIAO nRF42840, with full (pictured) and partial refresh modes. (\ud83d\udcf9: Hari R.)<\/p>\n<p class=\"hckui__typography__bodyL\">The heart of the project is a Seeed Studio XIAO nRF52840, one of the growing XIAO family of ultra-compact yet USB-ready development boards \u2014 in this case using the Nordic Semi nRF52840 chip on-board. This is connected to a GoodDisplay 1.54&#8243; 200\u00d7200 ePaper screen, which keeps the power draw down by requiring energy only when changing states. There&#8217;s an Analog Devices DS3231 real-time clock with battery backup to keep time, and a 3.7V lithium-polymer battery to keep everything running.<\/p>\n<p class=\"hckui__typography__bodyL\">The watch features two refresh modes. Every minute, the display performs a partial refresh to update the time; every ten minutes, it performs a full refresh while automatically switching to a randomly-selected graphic. &#8220;I did spend a lot of time creating watchfaces,&#8221; Hari R. admits, with 54 available at the time of writing. The software also includes three level of power optimization, depending on how precise you want the per-minute updates to be.<\/p>\n<p class=\"hckui__typography__bodyL\">Source code for the project has been published <a href=\"https:\/\/github.com\/haricane8133\/graytimer?tab=readme-ov-file\" class=\"hckui__typography__linkBlue\" rel=\"nofollow noopener\" target=\"_blank\">on GitHub<\/a> under an unspecified license, with more information available <a href=\"https:\/\/old.reddit.com\/r\/arduino\/comments\/1p8kzg6\/graytimer_simple_and_crude_diy_epaper_watch\/\" class=\"hckui__typography__linkBlue\" rel=\"nofollow noopener\" target=\"_blank\">in Hari R.&#8217;s Reddit thread<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Maker Hari R. has designed a 3D-printable ePaper watch that, unlike its arguably more polished rivals, doesn&#8217;t require&hellip;\n","protected":false},"author":2,"featured_media":319067,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[49,48,195,61],"class_list":{"0":"post-319066","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-gadgets","8":"tag-ca","9":"tag-canada","10":"tag-gadgets","11":"tag-technology"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/319066","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=319066"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/319066\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/319067"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=319066"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=319066"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=319066"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}