MQTT Pager Build is Bringing Beepers Back
<img width="800" height="450" src="![image](https://hackaday.com/wp-content/uploads/2025/12/I-Built-An-On-Call-Pager-_-ESP32-1-13-screenshot.png?w=800")
alt=""/>Pagers were once a great way to get a message to someone out in public; they just had to be cool enough to have one. These days, they’re mostly the 
alt=""/>Pagers were once a great way to get a message to someone out in public; they just had to be cool enough to have one. These days, they’re mostly the Hackaday
MQTT Pager Build Is Bringing Beepers Back
Pagers were once a great way to get a message to someone out in public; they just had to be cool enough to have one. These days, they’re most...
Hackaday
MQTT Pager Build Is Bringing Beepers Back
Pagers were once a great way to get a message to someone out in public; they just had to be cool enough to have one. These days, they’re most...
![image](https://hackaday.com/wp-content/uploads/2025/12/battleborn_lfp_battery_cut_open_will_prowse_youtube.jpg?w=800")
alt=""/>Would you feel confident in buying US-made LiFePO4 (LFP) batteries? While the answer here is generally expected to be ‘yes’, especially compared to getting an unbranded LFP battery off eBay 
![image](https://hackaday.com/wp-content/uploads/2025/12/spo256-featured.jpg?w=800")
alt=""/>In a curious historical twist, the “Twelve days of Christmas” are actually the days of revelry that followed the 25th. The preceding period, Advent, was traditionally a fast, not unlike 
![image](https://hackaday.com/wp-content/uploads/2025/12/How-To-Build-the-BEST-3D-Printed-sim-racing-SHIFTER-Supercar-feeling-for-CHEAP-8-20-screenshot.png?w=800")
alt=""/>These days, sim racing is more realistic than ever. There are better screens, better headsets, and better steering wheels with better force-feedback, all of which help make you feel like 
![image](https://hackaday.com/wp-content/uploads/2025/12/rotoforge_tool_head.png?w=800")
alt=""/>Printing metal as easily as it is to printed with thermoplastics has been a dream for a very long time, with options for hobbyists being very scarce. This is something 
![image](https://hackaday.com/wp-content/uploads/2025/12/This-DIY-3D-Printed-Camera-Lens-Creates-Pixel-Art-1-7-screenshot.png?w=800"){kind=tracking}
alt=""/>We seldom talk about 3D printing lenses because most techniques can’t possibly produce transparent parts of optical quality. However, you can 3D print something like a lens, as [Luke Edwin] demonstrates, 
![image](https://hackaday.com/wp-content/uploads/2025/03/CELL_BE_processor_PS3_board.jpg?w=800")
alt=""/>Key to efficient hardware emulation is an efficient mapping to the underlying CPU’s opcodes. Here one is free to target opcodes that may or may not have been imagined for 
![image](https://hackaday.com/wp-content/uploads/2025/12/This-3D-printed-camera-lens-is-surprisingly-good-12-0-screenshot.png?w=800")
alt=""/>Disposable cameras are a fun way to get into classical photography. However, they can also be a valuable source of interesting parts that can be put to other uses. For 
![image](https://hackaday.com/wp-content/uploads/2025/12/331781765314157325_f1cd80-e1765778255482.jpg?w=800")
alt=""/>There are plenty of lovely e-readers out on the market that come with an nice big e-paper display. There aren’t nearly as many that come with two. [Martin den Hoed] developed the 
![image](https://hackaday.com/wp-content/uploads/2025/12/hall.png?w=800")
alt=""/>If you read about Hall effect sensors — the usual way to detect and measure magnetic fields these days — it sounds deceptively simple. There’s a metal plate with current 
![image](https://hackaday.com/wp-content/uploads/2025/12/mems_silicon_resonator_yutao_xu_microsystems_eng_2025.jpg?w=800")
alt=""/>Currently quartz crystal-based oscillators are among the most common type of clock source in electronics, providing a reasonably accurate source in a cheap and small package. Unfortunately for high accuracy 
![image](https://hackaday.com/wp-content/uploads/2025/12/CROSSCAB-ROAD-TRIP-Griffin-Riley-ILCE-1-12-05-25-64-1536x1024-1.jpg?w=800")
alt=""/>There’s no accounting for taste, but it’s hard to argue with The Autopian when they declare that this Nixie tube dash by [David Forbes] is “the coolest speedometer of all 
![image](https://hackaday.com/wp-content/uploads/2025/12/armsid_sid_replacement_ben_eater_youtube.jpg?w=800")
alt=""/>Despite the Commodore 64 having been out of production for probably longer than many Hackaday readers have been alive, its SID audio chip remains a very popular subject of both 
![image](https://hackaday.com/wp-content/uploads/2025/12/Screenshot-2025-12-17-at-10-39-56-3D-Printer-VOC-Calculator-%E2%80%93-HEATFORGE3D.png?w=800")
alt=""/>We love 3D printing here, but we also love clean air, which produces a certain tension. There’s no way around the fact that printing produces various volatile organic compounds (VOCs), 
![image](https://hackaday.com/wp-content/uploads/2025/12/esp32-c3_super_mini_boards_hacker_university_youtube.jpg?w=800")
alt=""/>Everyone loves tiny microcontroller boards, and the ESP32-C3 Super Mini boards are no exception. Unfortunately if you just casually stroll over to your nearest online purveyor of such goods to 
![image](https://hackaday.com/wp-content/uploads/2025/12/The-4-Speaker-That-Money-Cant-Buy-9-18-screenshot.png?w=800")
alt=""/>[Distracted by Design] loves gear from the 1980s, though some of it isn’t as useful as it used to be. He happened across a cheap old FM radio with a 
![image](https://hackaday.com/wp-content/uploads/2025/12/Doctors-had-no-answer-for-my-Grandma-so-I-built-one.-2-49-screenshot-1.png?w=800")
alt=""/>[It’s Triggy!] had a problem to solve. His grandma was having issues with hand tremors, which made the basic tasks of daily life difficult to perform. He decided to explore 
![image](https://hackaday.com/wp-content/uploads/2021/07/Keebin.jpg?w=800")
alt="Illustrated Kristina with an IBM Model M keyboard floating between her hands."/>What do you look for in a travel keyboard? For me, it has to be split, though this condition most immediately demands a carrying solution of some kind. Wirelessness I 
![image](https://hackaday.com/wp-content/uploads/2025/12/n900-hacks-featured.jpg?w=800")
alt=""/>Can a long-obsolete Linux phone from 2009 be of use in 2025? [Yaky] has a Nokia N900, and is giving it a go. Back in the 2000s, Nokia owned the mobile 
![image](https://hackaday.com/wp-content/uploads/2017/08/memory.jpg?w=800")
alt=""/>To the surprise of almost nobody, the unprecedented build-out of datacenters and the equipping of them with servers for so-called ‘AI’ has led to a massive shortage of certain components. 