Søren Kjærsgaard<p>I needed a simple code lock for this years <a href="https://techhub.social/tags/jotajoti" class="mention hashtag" rel="tag">#<span>jotajoti</span></a> <a href="https://techhub.social/tags/scout" class="mention hashtag" rel="tag">#<span>scout</span></a> event - won’t reveal why just yet 🙂</p><p>Everything these days revolves around microcontrollers and sure, easy to do, however I needed simplicity and 9V battery power, outside at potentially freezing temperatures and it also needs to be low cost, I plan to use at least three of them.. </p><p>Came across this simple circuit, almost too simple to be true, but it does the job just fine: push the four buttons in the right order and the output is enabled. Bingo 😃</p><p>Not overly secure but for my purposes, it’s a perfect little vintage code lock 🔐👌🏼☺️</p><p><a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="tag">#<span>hamradio</span></a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="tag">#<span>electronics</span></a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="tag">#<span>electronicsengineering</span></a> <a href="https://techhub.social/tags/vintage" class="mention hashtag" rel="tag">#<span>vintage</span></a> <a href="https://techhub.social/tags/cmoslogicfamily" class="mention hashtag" rel="tag">#<span>cmoslogicfamily</span></a> <a href="https://techhub.social/tags/cmos" class="mention hashtag" rel="tag">#<span>cmos</span></a> <a href="https://techhub.social/tags/digitaldesign" class="mention hashtag" rel="tag">#<span>digitaldesign</span></a> <a href="https://techhub.social/tags/jota" class="mention hashtag" rel="tag">#<span>jota</span></a> <a href="https://techhub.social/tags/joti" class="mention hashtag" rel="tag">#<span>joti</span></a></p>