{"id":195,"date":"2018-01-08T11:02:35","date_gmt":"2018-01-08T03:02:35","guid":{"rendered":"https:\/\/zsq.im\/wordpress\/?p=195"},"modified":"2018-03-18T11:26:46","modified_gmt":"2018-03-18T03:26:46","slug":"%e5%b0%86%e6%91%a9%e5%b0%94%e6%96%af%e7%94%b5%e9%94%ae%e6%94%b9%e9%80%a0%e4%b8%bausb%e9%94%ae%e7%9b%98","status":"publish","type":"post","link":"https:\/\/zsq.im\/wordpress\/%e5%b0%86%e6%91%a9%e5%b0%94%e6%96%af%e7%94%b5%e9%94%ae%e6%94%b9%e9%80%a0%e4%b8%bausb%e9%94%ae%e7%9b%98\/","title":{"rendered":"\u5c06\u6469\u5c14\u65af\u7535\u952e\u6539\u9020\u4e3aUSB\u952e\u76d8"},"content":{"rendered":"

\u8fd9\u7bc7\u6587\u7ae0\u7ffb\u8bd1\u81ea\uff1aI Turned my Dad’s 1950s Morse Key into a USB Keyboard<\/a><\/p>\n

\"\"<\/a><\/p>\n

The finished Morse key sitting happily on my laptop. Full project details below.
\n\u6700\u7ec8\u5b8c\u6210\u7684\u83ab\u5c14\u65af\u952e\u76d8\u4e0e\u7b14\u8bb0\u672c\u7535\u8111\u7684\u5408\u5f71\uff5e\u6574\u4e2a\u9879\u76ee\u7684\u7ec6\u8282\u5982\u4e0b\uff1a<\/p>\n

Background: I can just about remember growing up around beautifully designed analogue devices like rotary dial phones, typewriters, and record players. I\u2019ve always like the idea of converting these largely defunct objects into digital devices, and my Dad\u2019s old Morse key seemed like a simple project to get started on.
\n\u80cc\u666f\uff1a\u6253\u4ece\u8bb0\u4e8b\u4ee5\u6765\uff0c\u6211\u5c31\u751f\u6d3b\u5728\u8bbe\u8ba1\u7cbe\u7f8e\u7684\u6a21\u62df\u8bbe\u5907\u7684\u73af\u5883\u4e2d\uff0c\u6bd4\u5982\u65cb\u8f6c\u5f0f\u62e8\u53f7\u7535\u8bdd\uff0c\u6253\u5b57\u673a\u548c\u5531\u7247\u673a\u3002\u6211\u4e00\u76f4\u6709\u628a\u8fd9\u4e9b\u5927\u90e8\u5206\u73b0\u5728\u4e0d\u5e38\u7528\u7684\u4e1c\u897f\u8f6c\u6362\u6210\u6570\u5b57\u8bbe\u5907\u7684\u60f3\u6cd5\uff0c\u800c\u8fd9\u5176\u4e2d\uff0c\u8001\u7238\u7684\u65e7\u83ab\u5c14\u65af\u7535\u952e\u770b\u8d77\u6765\u50cf\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u9879\u76ee\u3002<\/p>\n

Morse code is an internationally recognised way of representing letters of the alphabet (a-z) and numbers (0\u20139) as a series of dots and dashes. During WW1 and WW2, it became a handy way of sending encrypted messages across long distances and quite possibly sent carrier pigeon unemployment rates skyrocketing. A conventional Morse key acts like a switch, making and breaking a circuit connection to transmit these dots and dashes as short and long beeps over radio waves.
\n\u83ab\u5c14\u65af\u7535\u7801\u662f\u4e00\u79cd\u5c06\u56fd\u9645\u516c\u8ba4\u7684\u5b57\u6bcd\u8868\uff08a-z\uff09\u548c\u6570\u5b57\uff080-9\uff09\u5b57\u6bcd\u8868\u793a\u4e3a\u4e00\u7cfb\u5217\u70b9\u548c\u7834\u6298\u53f7\u7684\u65b9\u5f0f\u3002\u5728\u4e00\u6218\u548c\u4e8c\u6218\u671f\u95f4\uff0c\u5b83\u53d8\u6210\u4e86\u4e00\u4e2a\u5341\u5206\u65b9\u4fbf\u53d1\u9001\u52a0\u5bc6\u7684\u4fe1\u606f\u7684\u65b9\u5f0f\u3002\u4f20\u7edf\u7684\u83ab\u5c14\u65af\u7535\u952e\u5c31\u50cf\u4e00\u4e2a\u5f00\u5173\uff0c\u8054\u901a\u548c\u65ad\u5f00\u7535\u8def\u8fde\u63a5\u5c31\u80fd\u901a\u8fc7\u65e0\u7ebf\u7535\u6ce2\u4f20\u64ad\u8fd9\u4e9b\u70b9\u548c\u70b9\u7684\u97f3\u957f\u3002<\/p>\n

The idea was that the Morse key would behave like a keyboard when plugged into any laptop or PC’s USB 3.0 port; the user could key in messages in Morse code, and the corresponding English alphanumeric characters would appear on screen. Code for the project is here (https:\/\/github.com\/nomblr\/morse\/<\/a>) and full details are below.
\n\u6240\u4ee5\u6211\u5c31\u60f3\u5230\u5f53\u63d2\u5165\u4efb\u4f55\u7b14\u8bb0\u672c\u7535\u8111\u6216 PC \u7684 USB 3.0 \u7aef\u53e3\u65f6\uff0c\u83ab\u5c14\u65af\u952e\u7684\u884c\u4e3a\u5c31\u50cf\u4e00\u4e2a\u952e\u76d8\uff1b \u7528\u6237\u53ef\u4ee5\u7528\u83ab\u5c14\u65af\u7535\u7801\u952e\u5165\u4fe1\u606f\uff0c\u5e76\u5728\u5c4f\u5e55\u4e0a\u51fa\u73b0\u76f8\u5e94\u7684\u82f1\u6587\u5b57\u6bcd\u6570\u5b57\u5b57\u7b26\u3002\u8fd9\u4e2a\u9879\u76ee\u7684\u4ee3\u7801\u6211 po \u5230\u4e86 Github \u4e0a\uff0c\u6709\u5fc3\u4eba\u90fd\u53ef\u4ee5\u53bb\u5c1d\u8bd5\u4e00\u4e0b\u3002<\/p>\n

\"\"<\/a><\/p>\n

The Morse key was incredibly dusty and attached to a nasty plastic base, so I took the whole thing apart, scrapped the base, and gave the Morse key a good clean.
\n\u83ab\u5c14\u65af\u7535\u952e\u79ef\u4e86\u5f88\u591a\u7070\u5c18\uff0c\u800c\u4e14\u88c5\u5728\u4e00\u4e2a\u5f88\u4e11\u7684\u5851\u6599\u57fa\u5730\u4e0a\uff0c\u56e0\u6b64\u6211\u51c6\u5907\u628a\u6240\u6709\u4e1c\u897f\u90fd\u62c6\u5f00\uff0c\u628a\u83ab\u5c14\u65af\u7535\u952e\u6e05\u6d01\u5e72\u51c0\u3002<\/p>\n

\"\"<\/a><\/p>\n

Some wet wipes did the job nicely, and I also sanded down the two metal contacts (the ‘switch’) a tiny bit to improve the electrical connection and remove some of the accumulated gunk.
\n\u4f7f\u7528\u6e7f\u7eb8\u5dfe\uff0c\u8fd9\u9879\u5de5\u4f5c\u5b8c\u6210\u7684\u5f88\u51fa\u8272\u3002\u5e76\u4e14\u6211\u8fd8\u4ed4\u7ec6\u6253\u78e8\u4e86\u4e24\u4e2a\u91d1\u5c5e\u89e6\u70b9\uff08\u201c \u5f00\u5173 \u201d\uff09\uff0c\u6539\u5584\u7535\u8def\u8fde\u63a5\u7684\u60c5\u51b5\u5e76\u53bb\u9664\u4e00\u4e9b\u6c89\u79ef\u7684\u810f\u4e1c\u897f\u3002<\/p>\n

\"\"<\/a><\/p>\n

 <\/p>\n

Converting the (VERY analogue) Morse key into a digital device was the next step. To do this I used a tiny, cheap micro-controller aptly named a Teensy 3.2 (https:\/\/www.pjrc.com\/teensy\/<\/a>). The Teensy has 28 pins, each of which can be configured as an input or an output; because I wanted to the Teensy to receive signals from the Morse key, I configured Pin 7 of the Teensy as an input and wired it to one connection on Morse key. (This was an arbitrary choice, any of the I\/O pins would have worked just fine.) I then wired the ground pin of the Teensy to the other connection on the Morse key.
\n\u63a5\u4e0b\u6765\u5c31\u662f\u5c06\u7535\u952e\u8f6c\u6362\u4e3a\u6570\u5b57\u8bbe\u5907\u3002\u4e3a\u4e86\u5b9e\u73b0\u8fd9\u4e00\u70b9\uff0c\u6211\u4f7f\u7528\u4e00\u4e2a\u5c0f\u5de7\uff0c\u4fbf\u5b9c\u7684\u5fae\u578b\u63a7\u5236\u5668\u2014\u2014Teensy 3.2\u3002<\/p>\n

This was my first foray into working with electronics or microcomputers so feel free to imagine a progress montage punctuated by thoughtful moustache stroking scenes, eighties music and gratuitous but entirely pointless shots of the terminal.
\n\u8fd9\u662f\u6211\u7b2c\u4e00\u6b21\u5c1d\u8bd5\u505a\u8fd9\u79cd\u4e8b\uff0c\u4f60\u53ef\u4ee5\u60f3\u8c61\u5f53\u6211\u70b9\u4eae\u5e76\u4e14\u6210\u529f\u8fd0\u884c\u7684\u65f6\u5019\uff0c\u6211\u7684\u5185\u5fc3\u662f\u591a\u4e48\u559c\u60a6\u3002<\/p>\n

I wrote some test code for the Teensy to make sure it was working with the Morse key as expected; I expected to see ‘KEY PRESS’ printed out once every time I pressed the Morse key down once. This is where I hit my first problem. Mechanical switches don\u2019t make perfect physical or electrical contact when they\u2019re pressed; they\u2019ll typically oscillate between being \u2018open\u2019 and \u2018closed\u2019 a few times over ~1ms before settling down to a stable \u2018closed\u2019 state. Microcomputers are fast enough to detect these oscillations so when I pressed my Morse key down just once, the Teensy detected several rapid key presses as shown in the photo. This effect is called \u2018bounce\u2019 and luckily there\u2019s a built-in Teensy library (https:\/\/playground.arduino.cc\/Code\/Bounce<\/a>) that compensates for it.<\/p>\n

\u4e3a\u4e86\u786e\u4fdd Teensy \u6b63\u786e\u6309\u7167\u9884\u671f\u201c \u7ffb\u8bd1 \u201d\u83ab\u5c14\u65af\u5bc6\u7801\uff0c\u6211\u4e3a Teensy \u5199\u4e86\u4e00\u4e9b\u6d4b\u8bd5\u4ee3\u7801\u3002\u56e0\u6b64\u6bcf\u5f53\u6309\u4e0b\u83ab\u5c14\u65af\u7535\u952e\u4e00\u6b21\uff0c\u6211\u5c31\u4f1a\u770b\u5230\u7535\u8111\u7aef\u6709\u5b57\u7b26\u8f93\u51fa\u3002\u7136\u800c\u5f88\u5feb\u6211\u5c31\u9047\u5230\u4e86\u4e00\u4e2a\u95ee\u9898\uff1a\u673a\u68b0\u5f00\u5173\u6309\u4e0b\u65f6\u4e0d\u80fd\u5f62\u6210\u5b8c\u7f8e\u7684\u7269\u7406\u63a5\u89e6 \uff08\u901a\u5e38\u5728\u201c \u901a\u8def \u201d\u548c\u201c \u65ad\u8def \u201d\u4e4b\u95f4\u6446\u52a8\u51e0\u6b21\uff0c\u6301\u7eed\u7ea6 1ms\uff0c\u7136\u540e\u7a33\u5b9a\u5230\u201c \u901a\u8def \u201d\u72b6\u6001\uff09\u3002\u8ba1\u7b97\u673a\u80fd\u591f\u5feb\u901f\u68c0\u6d4b\u5230\u8fd9\u4e9b\u632f\u8361\uff0c\u6240\u4ee5\u5f53\u6211\u6309\u4e0b\u6211\u7684\u83ab\u5c14\u65af\u7535\u952e\u65f6\uff0cTeensy \u68c0\u6d4b\u5230\u7167\u7247\u4e2d\u663e\u793a\u7684\u51e0\u4e2a\u5feb\u901f\u6309\u952e\u3002\u8fd9\u79cd\u6548\u5e94\u79f0\u4e3a\u201c \u53cd\u5f39 \u201d\uff0c\u5e78\u597d\u5185\u7f6e\u7684 Teensy \u5e93\u80fd\u591f\u8865\u507f\u5b83\u3002<\/p>\n

Once the Teensy could successfully detect single Morse key presses, I needed a way to differentiate the pauses between dots, dashes, letters, and words. Implementing a method for the Teensy to figure out relative timings for individual users would\u2019ve involved a fair amount of faff, so I used absolute timings based on my own keying speeds. A threshold of 150ms was used to differentiate dots from dashes, and pauses between letters and words were set to 500ms and 3000ms. Of course, this configuration will break down with a faster or slower Morse operator, but as my old engineering tutor used to say, \u201cgood engineers are smart but lazy,\u201d which for the purposes of this project I will choose to interpret as \u201cgood engineers are lazy\u201d.<\/p>\n

\u4e3a\u4e86 Teensy \u80fd\u591f\u6210\u529f\u68c0\u6d4b\u5230\u6bcf\u6b21\u70b9\u51fb\u83ab\u5c14\u65af\u7535\u952e\u7684\u4e0d\u540c\uff0c\u6765\u533a\u5206\u70b9\u3001\u7834\u6298\u53f7\u3001\u5b57\u6bcd\u548c\u5355\u8bcd\u4e4b\u95f4\u7684\u505c\u987f\u3002\u6211\u5728\u7edd\u5bf9\u65f6\u95f4\u7684\u57fa\u7840\u4e0a\u7ed3\u5408\u81ea\u5df1\u7684\u952e\u63a7\u901f\u5ea6\u3002\u7528 150ms \u7684\u9608\u503c\u6765\u533a\u5206\u77ed\u5212\u7ebf\uff0c\u5e76\u4e14\u5b57\u6bcd\u548c\u5355\u8bcd\u4e4b\u95f4\u7684\u65f6\u95f4\u95f4\u9694\u88ab\u8bbe\u7f6e\u4e3a 500ms \u548c 3000ms\u3002\u5f53\u7136\uff0c\u6bcf\u4e2a\u4eba\u7684\u4e60\u60ef\u90fd\u4e0d\u4e00\u6837\uff0c\u8fd9\u4e2a\u5c31\u8981\u81ea\u5df1\u628a\u63e1\u4e86\u3002<\/p>\n

\"\"<\/p>\n

With the Teensy fully programmed, I was ready to build a wooden base to hide the electronics underneath the Morse key, with holes to feed through the two wires connecting the Morse key to the Teensy. I\u2019d like to say I chose wood for aesthetic reasons, but in reality all my attempts at 3D printing a base failed so abysmally that I decided to try my luck with a plank I found lying around at my local Hackspace, of approximate width 130mm and depth 20mm.
\nTeensy \u7f16\u7a0b\u5b8c\u540e\uff0c\u6211\u51c6\u5907\u5236\u4f5c\u4e00\u4e2a\u9690\u85cf\u83ab\u5c14\u65af\u7535\u952e\u4e0b\u65b9\u7684\u7535\u5b50\u8bbe\u5907\u7684\u6728\u8d28\u5e95\u5ea7\uff0c\u5e76\u4e14\u5e95\u5ea7\u4e0a\u6709\u4e24\u4e2a\u5b54\uff0c\u7528\u4e8e\u8fde\u63a5 Teensy \u5230\u83ab\u5c14\u65af\u7535\u952e\u7684\u7535\u7ebf\u3002\u4e3a\u5565\u9009\u6728\u6750\u800c\u4e0d\u662f 3D \u6253\u5370\u5462\uff1f\u5176\u5b9e\u4e0d\u662f\u7f8e\u89c2\u4e0d\u7f8e\u89c2\u7684\u95ee\u9898\uff0c\u800c\u662f\u56e0\u4e3a\u7528 3D \u6253\u5370\u51fa\u6765\u7684\u5e95\u5ea7\u90fd\u9002\u914d\u5931\u8d25\u4e86\u3002<\/p>\n

\"\"<\/a><\/p>\n

I sawed the plank down to 110x90mm so the Morse key would fit nicely on top, and chiselled out an indentation of approximate dimensions 50x40x10mm on the underside, so fit the Teensy and wiring.
\n\u6211\u628a\u6728\u677f\u952f\u6210 110x90mm\uff0c\u8fd9\u6837\u83ab\u5c14\u65af\u7535\u952e\u53ef\u4ee5\u5f88\u6070\u5f53\u5730\u653e\u5728\u4e0a\u9762\u3002\u5728\u4e0b\u65b9\u6211\u51ff\u51fa\u4e86\u4e00\u4e2a\u5c3a\u5bf8\u7ea6\u4e3a 50x40x10mm \u7684\u51f9\u75d5\uff0c\u7528\u4e8e\u653e\u7f6e\u5fae\u63a7\u5236\u5668 Teensy \u548c\u5e03\u7ebf\u3002<\/p>\n

\"\"<\/a><\/p>\n

I sanded the whole thing down and connected it to my laptop. You can see it in action here: https:\/\/www.youtube.com\/watch?v=qh_apYcr4xI<\/a>
\n\u6700\u540e\u6211\u6253\u78e8\u4e86\u4e00\u4e0b\u65b0\u7684\u952e\u76d8\uff0c\u5e76\u5c06\u5176\u8fde\u63a5\u5230\u6211\u7684\u7b14\u8bb0\u672c\u7535\u8111\u4e0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u8fd9\u7bc7\u6587\u7ae0\u7ffb\u8bd1\u81ea\uff1aI Turned my Dad’s 1950s Morse Key into a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-195","post","type-post","status-publish","format-standard","hentry","category-technology"],"_links":{"self":[{"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/posts\/195","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/comments?post=195"}],"version-history":[{"count":1,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/posts\/195\/revisions"}],"predecessor-version":[{"id":196,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/posts\/195\/revisions\/196"}],"wp:attachment":[{"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/media?parent=195"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/categories?post=195"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zsq.im\/wordpress\/wp-json\/wp\/v2\/tags?post=195"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}