It all started with a bad smell coming from the heat register. [CuddleBurrito] recalled a time when something stinky ended up in the ductwork of his folks’ house which ended up costing them big bucks to explore. The hacker mindset shies away from those expenditures and toward literally rolling your own solution to investigating the funk. In the process [CuddleBurrito] takes us on a journey into the bowels of his house.
Meet project Oro, the temperature monitoring watchdog. Err… the watchdog monitoring temperature probe. Well, it’s both actually!
[Richard Deininger] built the project after having the AC system go down in his company’s server room. That environmental cooling is imperative if you don’t want your server hardware turned to slag. The idea is a separate piece of hardware that monitors the room temperature and will alert the on-call staff if it climbs too high. He was successful, and showing the hacked hardware around the office came up with a second idea: a temperature sensor for your car to ensure it’s not too hot for your dog.
Anyone who has a canine friend living with them knows you don’t utter the word “ride” out loud lest a barking, whimpering, whining frenzy ensue. But jingle those keys and they’ll be at the door in no time. During the summer you can still take them with you for short errands thanks to the peace of mind [Richard’s] build provides. It’s simply an Arduino, DHT22 temp/humidity probe, and a SIM900 GSM modem. Set your temperature threshold and you’ll get an alert if temperatures are climbing to unsafe levels for Fido.
While you have your tools out, we recommend building auto-watering and auto-feeding systems for the family pets. What’s that? You hate domesticated animals? There’s a hack you can use to chase them from your yard.
How hot are your key components getting? There’s a good chance you’ve built a project and thought: “Well I guess I better slap a heat sink in there to be safe”. But when working on a more refined build you really need to calculate heat dissipation to ensure reliability. This is actually not tough at all. The numbers are right there in the datasheet. Yes, that datasheet packed with number, figures, tables, graphs, slogans, marketing statements, order numbers… you know right where to look, don’t you?
Hackaday has you covered on this one. In under 10 minutes [Bil Herd] will not only show how easy these calculations are, he’ll tell you where to look in the datasheets to get the info you need quickly.
[Bob] and his wife use a bed heating pad. In the winter, they typically turn it on about an hour before bedtime so the bed is nice and warm. The problem is, if they accidentally leave it on, they’ll wake up a few hours later: overheated. What they needed was an advanced timer system.
A normal outlet timer wouldn’t fit his needs: most of the year the pad should shut off after a slight delay, but in the winter they prefer to leave the heating pad on at a much lower temperature. [Bob] decided to create a custom timer with a microcontroller to provide adjustable duration and heating levels.
The circuit is simple. It consists of a microcontroller, a 2-digit LED display, two buttons, and two wires that connect to the heating pad’s original controller. The final build allows you to set the time the pad turns on, turns off, and/or down a few levels. It’s a fantastic hack, and you can see how the interface works in the video following the break.
[James] builds all sorts of robots and superhero costume replicas at home, so he is always searching for a better way to get consistent results when using his vacuum table. A lot of people use their oven or exposed heating coils from electric frying pans to warm the plastic sheets, but [James] wasn’t really interested in going down that route. He cites that he would rather not heat plastic in the oven where he cooks his food, nor is he really keen on the idea of exposed heating elements.
Instead, he opted for a slightly pricier, though completely reasonable setup that produces consistent results every time. Most of the forming table was built using MDF sheeting, as you can see in the video below. His heating apparatus was the most expensive part of the rig, since it’s an off the shelf quartz-based room heater. He lays the heater on its back side, and directs the heat up through an MDF frame using aluminum foil as a reflector. The plastic sheeting mounted at the top heats evenly, and in no time, he has a perfectly vacuum formed prop that is ready to be painted.
Sure, it might cost a bit more than some other vacuum formers we’ve looked at before, but spending a bit more up front to get consistent results is well worth it if you ask us.
[Sprite_TM] built a full clock display using thermochromic paint. This picks up where he left off with his paint-based 7-segment display prototype. He never really saw that design through to a finished project, but he recently came across the leftover paint and decided to do something with it. Instead of making thin traces on a PCB he’s heating up resistors mounted on protoboard. Each resistor has been coated with the black/light grey paint after getting a rough sanding on the tops of the packages. Run around 500mW through a segment and they heat up enough to change the paint to light grey. Once shut off, the segments gradually fade over the next 60 seconds.
[SXRguyinMA] built a replacement top bezel for his computer case. He wanted to add vents that would automatically open or close based on the cooling needs of the computer. With some careful measurements he modeled the parts in Sketchup and sent out for them to be cut from styrene with a water jet cutter. The parts came back looking great and the assembly of the shutters went swimmingly. The bezel also includes a lighted screen for temperature information, as well as the front USB ports, headphone and mic jacks, etc. Hidden underneath is an Arduino board and servo motor. The Arduino polls the temperature and drives the servo to adjust the fins accordingly. There’s even a supercap in the circuit that will close the vents when the PC powers down or when power is unexpectedly lost. See it in action after the break.