7 Segment LED Clock

prusaprinters

<h3><strong>Introduction</strong></h3><p>My entry for the PrusaPrinters “Timekeepers” contest <strong>(Don't forget to give it a like...)</strong></p><figure class="media"><oembed url="https://youtu.be/NBPBxQH7S8Q"></oembed></figure><p>Some ideas for upcoming versions:</p><ul><li>Software<ul><li><strong>DONE</strong> - Integrate WiFiManager for easier setup</li><li><strong>DONE</strong> - Configure the timezone/time offset in a Web GUI (set automatically during WiFiManager configuration)</li><li><strong>DONE</strong> - Show temperature</li><li>OTA (Over The Air) Updates</li><li>Set the brightness depending on time of day or a brightness sensor</li><li>Buttons to change the brightness and color</li></ul></li><li>Hardware<ul><li>Back lid to mount it on a wall</li><li>Bring down the thickness to around 30mm for wall mounting (40mm is fine for the desktop version)</li><li>Buttons</li></ul></li></ul><h3>Updates</h3><p><strong>30.05.2021:</strong></p><ul><li>Added back lid without ESP32 mount (STL and Step file for customisation)</li><li>Fixed a small issue in the code: The first digit of the hour doesn't disappear when switching from 23:59 to 0:00</li></ul><p><strong>02.06.2021:</strong></p><ul><li>Updated frame and back lid files (Increased the cable opening from 3.5 to 4.1 mm to support thicker USB cables)</li></ul><p><strong>18.06.2021:</strong></p><ul><li>The code is available at <a href="https://github.com/ursweiss/7-Segment-LED-Clock/tree/main">GitHub</a> now (removed the .ino file from downloads)</li><li>Made a lot of code changes:<ul><li>Implemented WiFiManager</li><li>Splitted the code into multiple files and separated the configuration</li><li>It's now possible to show the temperature of a given location in a predefined Interval</li><li>Shows the status of the clock during startup</li><li>It's able to display different characters now if needed (for upcoming features i don't know yet)</li><li>Can show error codes “Er00” to “Er99” in case something fails (Very basic for now and not documented yet)</li><li>Various small cleanups and improvements</li></ul></li></ul><h3><strong>Print instructions</strong></h3><p>The printer needs to be able to print at lease 240mm and therefore will not fit onto the MINI, I'm sorry.</p><p>The 3mf files are prepared to print right out of the box.</p><p><strong>The “Segments” part needs a color change at 1mm</strong> (after printing the 0.8mm/4th layer). The first four layers should be printed in white, the rest of the layers in silver (ideally something that reflects, but doesn't let much light through). If printed completely in white, it will not look good at all. Don't try it, I did as a test, doesn't work at all.</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/f3264ecf-4a26-43b7-b03c-ce972fc90012/img_7424.jpg#%7B%22uuid%22%3A%22ed4e4077-55d2-4497-92fb-2bef366e055d%22%2C%22w%22%3A4032%2C%22h%22%3A2592%7D"></figure><h3>Additional parts required</h3><ul><li><a href="https://www.aliexpress.com/item/4000152270368.html?spm=a2g0s.9042311.0.0.61af4c4dESOka0">ESP32 DEVKITV1</a> (ESP-WROOM-32)<br>Only this one will fit into the prepared holder on the back lid</li><li><a href="https://www.aliexpress.com/item/32992177359.html?spm=a2g0s.9042311.0.0.27424c4dOWO2zh">W2812B LEDs</a> (pre-soldered onto a round 10mm PCB)</li><li><a href="https://s.click.aliexpress.com/e/_AXqnsF">Logic Level Converter</a> to convert the 3.3V signal to 5V</li><li><a href="https://www.aliexpress.com/item/32959521425.html?spm=a2g0s.9042311.0.0.27424c4dq4kV70">Micro USB Power Supply</a></li><li>Optional: A capacitor of around 450µF (I think it's not really needed, but doesn't hurt…)</li></ul><h3>Load the code</h3><p>Download the most current version of the code from <a href="https://github.com/ursweiss/7-Segment-LED-Clock/tree/main">GitHub</a> and follow the instructions there.</p><h3>Assembly</h3><h4>Glueing in the LEDs</h4><p>I used a hot glue gun to glue in the LEDs. Just worked very well for me in many projects and has the advantage, that you can get the LED out again much more easily in case you have to replace one.</p><p>This is the order in which the LEDs have to be glued in to work with the provided code (the two LEDs of the colon have to be the last ones):</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/a0cf7f5c-8014-42d2-8dd4-39a1895d2857/img_2108.jpg#%7B%22uuid%22%3A%2212697ab5-71dc-4a07-8e82-d934e3d97a1f%22%2C%22w%22%3A3174%2C%22h%22%3A2651%7D"></figure><h4>Soldering the LEDs</h4><p>I use blank wire for each segment and stranded/isolated wire to connect them. It's much easier and faster to use blank wire (you anyway should solder fast if you used hot glue…).</p><p>Do one path at a time and only solder it to one pad (I apply a bit of solder to one of the pads of each LED first and then just heating it up again to solder on the wire):</p><figure class="image image-style-align-center"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/89fedb78-1958-4273-8156-0af6ba7dab6d/img_2112.jpg#%7B%22uuid%22%3A%22d7958bc8-2101-4f1b-a588-51e8d462103f%22%2C%22w%22%3A1458%2C%22h%22%3A2345%7D"></figure><p>Then solder the second pad of each LED.</p><p>Repeat this for the other two paths:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/1b018dcc-b2ac-4b3d-ac67-c286985110f8/img_2113.jpg#%7B%22uuid%22%3A%22df7fda5b-81bf-43a4-b11f-7e3d0f665186%22%2C%22w%22%3A1373%2C%22h%22%3A2159%7D"></figure><p>The middle one is special, because it's the data line and the IN and OUT pads must not be connected. Use a side cutter to cut out a piece (or solder them one by one if you really like to):</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/b17bb948-2b2d-4b6b-83f3-ca4785a26ed0/img_2116.jpg#%7B%22uuid%22%3A%220bd06a05-761f-4a74-8d9d-e385134f5dcc%22%2C%22w%22%3A1746%2C%22h%22%3A1554%7D"></figure><p>And the third one:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/ceef2dd2-a131-4038-b8f8-0726de5c8b54/img_2117.jpg#%7B%22uuid%22%3A%22eb1b3f89-aff4-48ea-9024-f02c207213dd%22%2C%22w%22%3A1256%2C%22h%22%3A1999%7D"></figure><p>At the end it should look like this:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/5a844481-e9ac-4649-b5fd-9b6afe103c77/img_2118.jpg#%7B%22uuid%22%3A%221d486fbb-ba7f-46d0-9e45-0d67e17e3f4f%22%2C%22w%22%3A5779%2C%22h%22%3A2651%7D"></figure><p>Then connect the single segments with stranded/isolated wire:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/a2c09b38-dd35-4047-b7f1-378ddf3953f1/img_2119.jpg#%7B%22uuid%22%3A%229c549e22-d0c9-4952-ac10-5d8e744c9016%22%2C%22w%22%3A5438%2C%22h%22%3A2476%7D"></figure><p>Solder on a long enough piece of wire to connect the first data input:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/ffc33f9e-6f40-41c8-9627-8c1a8e75e97d/img_2124.jpg#%7B%22uuid%22%3A%2272640c97-4722-45d6-ba38-fc9075391433%22%2C%22w%22%3A5230%2C%22h%22%3A2586%7D"></figure><h4>The rest of the electronics</h4><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/3b58fa07-f4bd-4b05-a76b-85ec41d08fb2/img_2125.jpg#%7B%22uuid%22%3A%22eb98bab8-e768-4216-a865-6ff8769ee5f8%22%2C%22w%22%3A5182%2C%22h%22%3A3118%7D"></figure><p>Just solder on long enough wires to reach the logic level converter or the LEDs with some extra wire (the two wires with larger diameter). The capacitor is optional. I added it because i had some flickering. Probably not needed.</p><p>These pins are needed:</p><ul><li><strong>VIN (5V) &amp; GND</strong> (Top right. The thiner ones will go to the logic level converter, the others to the LEDs)</li><li><strong>3.3V &amp; GND</strong> (Top left. To the level converter)</li><li><strong>D4</strong> (below the left GND. To the level converter too)</li></ul><h4>Putting it all together</h4><p>Slide in the segments into the frame from the side:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/89665fad-9392-4ed1-a82e-9b350287975c/img_2126.jpg#%7B%22uuid%22%3A%22d3ff6a1a-51b7-476b-9fbe-5c103d299f0f%22%2C%22w%22%3A5620%2C%22h%22%3A2393%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/e48b98b1-cfe6-42a6-8345-32dd26cad75e/img_2127.jpg#%7B%22uuid%22%3A%2207de2aa4-7941-4e22-afbb-0bf732f9c377%22%2C%22w%22%3A6138%2C%22h%22%3A2830%7D"></figure><p>Push it down and make sure it snaps in properly:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/9670fdfb-aec8-4ec8-913a-ec108dd3451b/img_2130.jpg#%7B%22uuid%22%3A%2277b01489-5239-4688-b77f-4fa3025eedde%22%2C%22w%22%3A5786%2C%22h%22%3A2890%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/a2d14ba0-b8e7-4788-8b14-cae97653a479/img_2134.jpg#%7B%22uuid%22%3A%2233fbe3a8-e7ff-4478-87f9-b2604f9d028e%22%2C%22w%22%3A5623%2C%22h%22%3A2798%7D"></figure><p>On the back lid, cut off the bridge:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/af56c9a7-3251-425f-ae75-fad3ccaa0efb/img_2141.jpg#%7B%22uuid%22%3A%2226267ee9-763c-4e16-8072-bea77b81e9bf%22%2C%22w%22%3A5080%2C%22h%22%3A2973%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/4fb2f844-903b-4596-8bf7-fa98e0c5d481/img_2142.jpg#%7B%22uuid%22%3A%229b25b836-9b42-4e1e-8832-332d8618f09e%22%2C%22w%22%3A4689%2C%22h%22%3A2481%7D"></figure><p>Glue in the logic level converter (There are different types of logic level converters. If yours is a different one, check out the data sheet how to wire them later):</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/118046a9-e5fd-4ba4-8466-9120201c4ec7/img_2143.jpg#%7B%22uuid%22%3A%22bf8db33c-bafe-476e-93e0-f25110c8c6ff%22%2C%22w%22%3A2090%2C%22h%22%3A1760%7D"></figure><p>Slide in the ESP32 (Install it as show, as it has two LEDs on the top side which will very likely shine through the front. You may can also desolder at least the red one, didn't try if it affects the functionality):</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/f4e88192-a967-47f4-9bc1-56dd46993061/img_2144.jpg#%7B%22uuid%22%3A%22910c0e91-98ad-4f0f-b984-8553c43ef94e%22%2C%22w%22%3A3706%2C%22h%22%3A2384%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/6aee63d1-61ef-48b0-968f-e98b9e83d723/img_2145.jpg#%7B%22uuid%22%3A%228e1a69a1-e0d6-4a9f-95c0-ec765cda77b5%22%2C%22w%22%3A4188%2C%22h%22%3A2766%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/265cf96e-9cb1-422b-b0cc-d65d354b511d/img_2146.jpg#%7B%22uuid%22%3A%225778829f-ca5e-48df-820c-0df4e35108ea%22%2C%22w%22%3A3846%2C%22h%22%3A2460%7D"></figure><p>Solder on the wires coming from the ESP32.<br>In case of the logic level converter i used, the 3.3V &amp; GND on the top, the 5V &amp; GND on the bottom and D4 on one of the low voltage inputs (top right in this case).<br>Ignore the wire on the bottom right for now (I took the photo after wiring everything).</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/61039835-1c80-45d5-8234-10895a3eaf47/img_2155.jpg#%7B%22uuid%22%3A%22b46d869a-5ae4-40e1-8c28-11be6904bb42%22%2C%22w%22%3A3353%2C%22h%22%3A2931%7D"></figure><p>Put the prepared frame and back lid side by side and solder on the rest of the wires.<br>The 5V &amp; GND should be soldered somewhere in the middle:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/a143ffb8-0ea2-4943-8919-89416a286ab7/img_2152.jpg#%7B%22uuid%22%3A%22f1c52abb-beb3-405d-b0d0-0bae7fb4c3f9%22%2C%22w%22%3A4706%2C%22h%22%3A3794%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/b9654cdd-f7ce-41ca-921e-fd6b7798bc5f/img_2154.jpg#%7B%22uuid%22%3A%2223609d71-3c92-4651-8357-a461526df4cc%22%2C%22w%22%3A2619%2C%22h%22%3A2310%7D"></figure><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/7256b658-d5d1-40b6-84a7-5183e88864a4/img_2153.jpg#%7B%22uuid%22%3A%2261650d2a-aeae-4998-bb2f-95f866ebe996%22%2C%22w%22%3A5022%2C%22h%22%3A3584%7D"></figure><p>Plug in the micro USB power adapter and put on the lid:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/0e4de388-c395-455b-919a-eeb233558e7c/img_2157.jpg#%7B%22uuid%22%3A%2275e76717-cebc-4d92-8d97-7d1509196368%22%2C%22w%22%3A5967%2C%22h%22%3A3531%7D"></figure><p>And we're done:</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68013/rich_content/d6f83807-6363-4441-83a5-9c06efc36967/img_2161.jpg#%7B%22uuid%22%3A%22db5c8e60-0560-494d-867f-4a5d9735c990%22%2C%22w%22%3A5061%2C%22h%22%3A3293%7D"></figure>