{"id":3623,"date":"2025-01-10T21:58:00","date_gmt":"2025-01-11T05:58:00","guid":{"rendered":"https:\/\/digitalnigel.com\/wordpress\/?p=3623"},"modified":"2025-03-18T22:31:01","modified_gmt":"2025-03-19T05:31:01","slug":"numitron-clock","status":"publish","type":"post","link":"https:\/\/digitalnigel.com\/wordpress\/?p=3623","title":{"rendered":"Numitron Clock"},"content":{"rendered":"\n

After watching a recent Technology Connections video<\/a> about Numitron tubes, I was inspired to pick some up to add to my dragon’s hoard of junk. A quick visit to eBay later, and a few less dollars in my bank account, and I had some new-old-stock tubes in hand.<\/p>\n\n\n\n

\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n<\/figure>\n\n\n\n

At first I wasn’t sure what I wanted to use them for, so the obvious answer is a clock. I did decide, that if I was going to make *yet another* clock, it was going to be a very nice one. <\/p>\n\n\n\n

Starting with the electronics, I put together a board using an ESP32, some shift registers and driver transistors, and a Real-Time Clock chip with battery backup to keep time even when the clock is unplugged.<\/p>\n\n\n\n

A little bit of bad Arduino code later, and we have a functional clock, with 12\/24hr modes, three brightness levels (done with PWM), and calibration methods so I can calibrate the cheap quartz crystal on the board against something better, like a GPSDO or my Rubidium standard. It won’t really be that accurate over the long term, but I can calibrate out enough error that you’ll never notice the clock being wrong before you have to re-set it again anyway next time daylight savings rolls around to give everyone the big middle finger.<\/p>\n\n\n\n

\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n<\/figure>\n\n\n\n

Next was to figure out a case for it. Obviously 3D printing would be an option, I thought about laser cut acrylic as well, but I didn’t think it really made for a polished enough end product, and the overall look seemed off to me. So I get to pretend like I’m a woodworker, and ordered some small blocks of maple and redwood (from already fallen trees) from a specialty wood supplier.<\/p>\n\n\n\n

\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n<\/figure>\n\n\n\n

And just like a TV cooking show, through the magic of a million hours of cutting, sanding, chiseling, gluing, finishing, and self-loathing that we’re not going to show you, it’s done!<\/p>\n\n\n\n

\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n<\/figure>\n\n\n\n

I’m really happy with both of them. The redwood and the maple both have some really appealing characteristics. I ended up keeping the maple one for myself, and giving the redwood one to my dad for the holidays. He displays his with a quartz crystal he was also gifted this year.<\/p>\n\n\n\n

\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n<\/figure>\n","protected":false},"excerpt":{"rendered":"

After watching a recent Technology Connections video about Numitron tubes, I was inspired to pick some up to add to my dragon’s hoard of junk. A quick visit to eBay later, and a few less dollars in my bank account, … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,13,20],"tags":[],"class_list":["post-3623","post","type-post","status-publish","format-standard","hentry","category-art","category-electronics","category-projects"],"_links":{"self":[{"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3623","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3623"}],"version-history":[{"count":2,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3623\/revisions"}],"predecessor-version":[{"id":3638,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3623\/revisions\/3638"}],"wp:attachment":[{"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/digitalnigel.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}