Heat Pump Gets Brain Transplant; Such Is Life In Latvia

February 28, 2017 by Dan Maloney 25 Comments

If you buy a used heat pump that was made in China and try to use it in Northern Europe, there are bound to be issues. If said heat pump ends up encased in a block of ice that renders it ineffective, you’ve got two choices: give up and buy a proper heater, or hack a new ice-busting brain board into the heat pump and get back to life.

fnfvpksiz6c8s0h-medium — A little too icy.

[Evalds] chose the latter course, obviously, and in the process he gives us a pretty good look at how heat pumps work and how to overcome their deficiencies. In [Evalds]’ Latvia, winters can be both cold and humid, which can worsen an inherent problem with air-coupled heat pumps: they tend to ice up. As the outside coil is cooled to pick up as much heat as possible from the outside air, water vapor condenses out on the coils and freezes. Most heat pumps account for this by occasionally running in reverse, heating the outdoor coils to clear the ice buildup. [Evalds]’ had nothing more than a simple timer to kick off the defrost cycle, and it wasn’t keeping up with the Latvian winter. An Arduino replaced the OEM controller, and wired up to temperature sensors and an IR sensor that watches for ice buildup on the lower part of the coil, the heat pump is now much better behaved.

Of course it wasn’t as smooth as all that — [Evalds] has some hoops to jump through, including EMI problems and a dodgy Arduino clone. But he stuck with it and brought the heat pump back online, likely at far less expense than HVAC techs would charge for a service call.

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Your Internet Of Things Speaks Volumes About You

February 26, 2017 by James Hobson 29 Comments

If only Marv and Harry were burglars today; they might have found it much easier to case houses and — perhaps — would know which houses were occupied by technically inclined kids by capitalizing on the potential vulnerability that [Luc Volders] has noticed on ThingSpeak.

As an IoT service, ThingSpeak takes data from an ESP-8266, graphs it, and publicly displays the data. Some of you may already see where this is going. While [Volders] was using the service for testing, he realized anyone could check the temperature of his man-cave — thereby inferring when the house was vacant since the location data also happened to be public. A little sleuthing uncovered several other channels with temperature data or otherwise tied to a location that those with nefarious intent could abuse.

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Touch Sensitive Cement With Just A Dash Of Neon

February 22, 2017 by Mike Szczys 11 Comments

For quite some time now we’ve seen people casting their own countertops and other surfaces out of cement. It’s a combination of mold-making and surface finishing that produces a smooth and durable surface at quite a low cost, if you don’t factor in damage done to your back when lifting the thing for installation.

This offering is a little bit different. [Elliott Spelman] built his own touch sensitive cement table top. When you place your grubby hands on the polished surface, a loop of neon lighting is switched on. This is thanks to a 4:1 mix of quick setting cement and iron oxide powder. Bare copper wire was laid around the edges of the surface to be encased by the cement for making connections later.

There were some sad moments when [Elliott] was removing the cast surface from the mold. He ended up cracking it and suggests others be liberal with their use of both wax on the mold before casting, and patience in removing the cement afterward. We might also suggest a strengthening agent like fiber reinforcement. The edges and surface can be sanded to the finish desired and in this case, attaching table legs was easy since the wooden underside of the mold remains on the bottom of the cement.

The neon lighting adds a retro touch to this build. It’s sad to see this technology dying away, so a resurgence of artisanal neon is great in our book. [Elliott] found a Bay Area arts collective called the Crucible which does a lot of art glass education to help him make two hoops of glass tube and fill them with the appropriate gasses. A capacitive touch sensor (once Atmel, now Microchip part) AT42QT2120 (datasheet) monitors the wire coming from the slab and switches the power supply for the tubes using a combination of relay board and Arduino Uno.

We find the prospect of positional sensing in doped cement fascinating. Anyone have ideas for adapting this technique so that a more long and narrow slab could have positional awareness within, say, a few inches? Let us know in the comments.

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Custom Parts Put IKEA Window Shades On IoT

February 19, 2017 by Dan Maloney 18 Comments

No matter what the project is about, we’re always suckers for nicely integrated builds with good fit and finish. There’s a certain appeal to rat’s nest wiring on a breadboard, and such projects are valuable because they push the limits. But eventually you need to go from prototype to product, and that’s where this IKEA window shade automation project shines.

Integration is more than just putting everything in a nice box, especially for home automation gear – it really needs to blend. [ehsmaes] roller blind motorization project accomplishes that nicely with a 3D-printed case for the electronics, as well as a custom case for the geared stepper motor to drive the shade. The drive replaces the standard spring-loaded cap on the end of the IKEA Tupplur shade, and the neutral color of both cases blends nicely with the shade and surroundings. The control electronics include a NodeMCU and a motor shield; [eshmaes] warns that narrow shades work just fine off of USB power, but that wider windows will need a power boost. The IoT end of things is taken care of by MQTT and OpenHab, allowing the shades to be raised and lowered to any position. The short video below shows the calibration procedure for the shade.

Need a primer on MQTT? We’ve got you covered. Or perhaps you need to control the windows rather than the treatments.

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Monitor All The Laundry Things With This Sleek IoT System

February 18, 2017 by Dan Maloney 18 Comments

If like us you live in mortal fear of someone breaking into your house when you’re on vacation and starting a dryer fire while doing laundry, this full-featured IoT laundry room monitor is for you. And there’s a school bus. But don’t ask about the school bus.

In what [seasider1960] describes as “a classic case of scope creep,” there’s very little about laundry room goings on that escapes the notice of this nicely executed project. It started as a water sensor to prevent a repeat of a leak that resulted in some downstairs damage. But once you get going, why not go too far? [seasider1960] added current sensing to know when the washer and dryer are operating, as well as to tote up power usage. A temperature sensor watches the dryer vent and warns against the potential for the aforementioned tragedy by sounding an obnoxious local alarm — that’s where the school bus comes in. The whole system is also linked into Blynk for IoT monitoring, with an equally obnoxious alarm you can hear in the video below. Oh, and there are buttons for testing each alarm and for making an Internet note to reorder laundry supplies.

We’ve seen a spate of laundry monitoring projects lately, all of which have their relative merits. But you’ve got to like the fit and finish of [seasider1960]’s build. The stainless face plate and in-wall mount makes for a sleek, professional appearance which is fitting with the scope-creepy nature of the build.

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Hacking On The Weirdest ESP Module

February 13, 2017 by Elliot Williams 33 Comments

Sometimes I see a component that’s bizarre enough that I buy it just to see if I can actually do something with it. That’s the case with today’s example, the ESP-14. At first glance, you’d ask yourself what AI Thinker, the maker of many of the more popular ESP8266 modules, was thinking.

The ESP-14 takes the phenomenally powerful ESP8266 chip and buries it underneath one of the cheapest microcontrollers around: the 8-bit STM8S003 “value line” chip. Almost all of the pins of the ESP chip are locked inside the RF cage’s metal tomb — only the power, bootloader, and serial TX/RX pins see the light of day, and the TX/RX pins are shared with the STM8S. The rest of the module’s pins are dedicated to the STM8S. Slaving the ESP8266 to an STM8S is like taking a Ferrari and wrapping it inside a VW Beetle.

I had never touched an STM8 chip before, and just wanted to see what I could do with this strange beast. In the end, ironically, I ended up doing something that wouldn’t be too far out of place on Alibaba, but with a few very Hackaday twists: a monitor for our washer and dryer that reports power usage over MQTT, programmed in Forth with a transparent WiFi serial bridge into the chip for interactive debugging without schlepping down into the basement. Everything’s open, tweakable, and the Forth implementation for the STM8S was even developed here on Hackaday.io.

It’s a weird project for the weirdest of ESP modules. I thought I’d walk you through it and see if it sparks you to come up with any alternative uses for the ESP8266-and-STM8S odd couple that is the ESP-14.

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An Astronomical Observatory For Your Front Yard

February 11, 2017 by Jenny List 11 Comments

[Barry Armstead] is an astronomy enthusiast who built his own observatory in his front yard, in Canberra, Australia. It was a fine observatory as home-made observatories go, but he describes it as being small and cramped. His replacement was on an entirely different scale though, a building created by hand and which no doubt many readers would be pleased to own.

His design started with a cardboard model, and has a downstairs room upon which sits a rotatable dome with two sliding sections to form the observation window. The original observatory’s concrete pillar on which the telescope mount stood remained post-demolition, and a larger concrete pad was laid. There followed the assembly of a steel frame with a skeletal dome able to rotate on rollers, followed by cladding with steel sheet. The dome cladding was done in segments marked against the dome steelwork and cut to shape.

The final building has a fully finished interior downstairs, plus a rustic staircase to the upper deck. The concrete post has been extended, and now carry’s [Barry]’s telescope which he controls not with his eye clued to an eyepiece like the astronomers of old, but from a computer at the adjacent desk. The full construction details are on the observatory’s web site, though since it seems in danger of disappearing due to an expired hosting account we’ll also give you a Wayback Machine link direct to the relevant page. Meanwhile he offers a tour in a video we’ve placed below the break. Even a non-astronomer would find this an asset in their garden!

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