DIY SSR For Mains Switching

May 17, 2018 by Anool Mahidharia 34 Comments

Typical power strips have their sockets tightly spaced. This makes it cumbersome to connect devices whose wall warts or power bricks are bulky — you end up losing an adjoining socket or two. And if the strip has a single power switch, you cannot turn off individual devices without unplugging them.

Planning to tackle both problems together, [Travis Hein] built himself some custom Dual SSR Controlled Socket Outlets for his workbench. He also decided to add remote switching ability so he could turn off individual sockets via a controller, Raspberry Pi, smartphone app or most ideally, a nice control panel on his desk consisting of a bank of switches.

The easiest solution for his problem would have been to just buy some off-the-shelf SSR or relay modules and wire them up inside his sockets. But he couldn’t find any with the features he wanted, and SSR’s were a little bit on the expensive side. Also, we wouldn’t have a project to write about – sometimes even the simple ones can show us a thing or two.

For starters, he walks us through a quick and simplified primer on figuring out thermal dissipation for the triacs which will be used on his boards. This is tricky since the devices are connected directly to utility voltage so he needs to take care of track clearances, mechanical separation as well as safety. However, for his first board prototypes, he did not add any heat sinking for the triacs, thereby limiting their use to low current loads. Since the SSR also needs to have a wide control voltage range, he describes how the two transistor constant-current input block works to limit opto-triac LED current over a range of 2 V to 30 V.

Before he moves on to his next prototype, [Travis] is looking for feedback to improve his design, make it safer, and figure out if it can pass safety protocols. Let him know via comments below.

Case Mod Takes “All In One” Printer To The Next Level

May 15, 2018 by Tom Nardi 14 Comments

You’ve seen printers with scanners in them, printers with copiers in them, even ones with the ancient technology known as “facsimile” built-in. But have you ever seen a printer with a full gaming computer built into it? No? Well, you still haven’t, technically. There’s no printer to be had anymore inside this re-purposed HP Photosmart 6520 case, but it’s probably the closest we’re going to get.

[Jacob Lee] wrote in to share this awesome build with us, which sees the motherboard, graphics card, ATX power supply, and hard drives all fit seamlessly into the shell of a disused “All-in-one” style printer. Incredibly, he even managed to integrate an LCD into the top; which hinges open when in use and gives a look down into the madness that makes this build tick.

To say there’s a lot of hardware packed into this thing is an understatement. Which is all the more impressive when you consider that he] didn’t take the easy way out for any of it. He could have used a mini-ITX motherboard, or a slim PSU. He could have even dropped the graphics card for integrated. No, [Jacob] is clearly a subscriber to the “Go big or go home” ethos.

As if putting all this gear inside of a normal looking printer case wasn’t impressive enough, he even went as far as adding female ports for Ethernet, HDMI, and USB on the rear of the device to give it a stock look. He mentions there’s some room for improvement with the USB ports, but the power switch and IEC port really look like they could have been original components.

In the age of the Raspberry Pi and other diminutive computers, we don’t see too many proper desktop computer projects anymore. Fewer still that are so well executed and creative. We don’t know how many other people might be trying to stick a computer in a printer case, but if they’re out there, the bar has just been set pretty high.

DIY Variacs Get ESP8266 Upgrades

May 14, 2018 by Tom Nardi 46 Comments

If you’be been hacking and making long enough, you’ve probably run into a situation where you realize that a previous project could be improved with the addition of technology that simply wasn’t available when you built it. Sometimes it means starting over from scratch, but occasionally you luck out and can shoehorn in some new gear without having to go back to the drawing board.

The two isolated variacs that [nop head] built were already impressive, but with the addition of the ESP8266 he was able to add some very slick additional features which really took them to the next level. He’s done an exceptional job detailing the new modifications, including providing all the source for anyone who might be walking down a similar path.

His variacs have digital energy meters right in the front panel which give voltage, amps, and a real-time calculation of watts. After reading an article by [Thomas Scherrer] about sniffing the SPI data out of one of these meters with an Arduino, [nop head] reasoned he could do the same thing with an ESP8266. The advantage being that he could then pull that data out over the network to graph or analyze however he wishes.

For his older variac, he decided to automate the device by adding a stepper and belt to turn the knob. The stepper is controlled by a Pololu stepper driver, which in turn get’s its marching orders from another ESP8266. He even came up with a simple web interface which allows you to monitor and control the variac from your smart device.

We don’t often see many variacs around these parts, and even fewer attempts at building custom ones. It’s one of those pieces of equipment you either can’t live without, or have never even heard of.

ESP Cookbook Goes Beyond Chips And DIPs

May 14, 2018 by Kristina Panos 13 Comments

Are you putting ESP8266s in all your projects these days, whether they need one or not? We don’t blame you. These boards are cheap, tiny, oh and they have WiFi.

If you want to spend less time writing code and more time blinking RGB LEDs over Wi-Fi, then check out this ESP cookbook over on IO. [Turo Heikkinen] and team are writing a soup-to-nuts guide to these darlings of IoT. The cookbook leads off with pinouts and networking (of course) before moving into more intricate recipes involving popular sensors and displays.

This cookbook is funny, it’s helpful, and it’s really well-organized. We love that they used the details section to create a linked table of contents. The links all drive to a specific Instructions page where each group of code snippets and explanations can be found. It’s still a work in progress, so you might want to follow it for updates. We have a feeling they’re going to expand the dessert section next.

Love the ESP8266, but hate programming them in that wonky form factor? Here’s a handy programming jig you can build.

Held Captive By Arduino And Multiple RFID Readers

May 13, 2018 by Tom Nardi 18 Comments

If you’re the kind of person who has friends, and/or leaves the confines of the basement from time to time, we hear that these “Escape Rooms” are all the rage. Basically you get locked into a room with a couple other people and have to solve various problems and puzzles until you’ve finally made enough progress that they let you out. Which actually sounds a lot like the working conditions here at Hackaday HQ, except they occasionally slip some pizza rolls under the door for us which is nice.

Whichever side you find yourself on in one of these lighthearted hostage situations, knowledge of this multi-tag RFID lock created by [Annaane] may come in handy. By connecting multiple MFRC522 RFID readers to an Arduino Uno, she’s come up with a method of triggering a device (like an electronic door lock) only when the appropriate combination of RFID tags have been arranged. With a little imagination, this allows for some very complex puzzle scenarios which are sure to keep your prisoners enthralled until you can lower the lotion down to them.

Her code allows you to configure the type and number of RFID cards required to trigger one of the Arduino’s digital pins, which usually would be connected to a relay to fire off whatever device you want. The Arduino sketch is also setup to give “hints” to the player by way of a status LED: fast blinking let’s you know the tag scanned is wrong, and slow blinking means you don’t have enough scanned in yet.

The video after the break shows some highlights of the build, as well as a quick demonstration of how both the RFID “combination” and manual override can be used to trigger the attached relay.

Hackers do love RFID. Using them for physical access control is a fairly common project around these parts, and we’ve even seen similar setups for the digital realm.

Continue reading “Held Captive By Arduino And Multiple RFID Readers” →

The Incredible Shrinking Rework Station

May 2, 2018 by Tom Nardi 18 Comments

Anyone who’s ever tried setting up a workbench in a tight space knows the struggle: you want to have all your test equipment and tools out and within arm’s reach, but you just don’t have enough surface area. If you fill the whole bench with your tools, there’s not going to be anywhere left to work. So you either have a bench full of tools that’s uncomfortable to use, or you’re forced to choose what stays out and what gets packed away. Neither is conducive to actually getting work done, which is why you are trying to set up a proper bench in the first place. It’s a vicious cycle.

When faced with that very problem recently, [EEpromChip] decided to take the nuclear option. His Kendal 853D was already a great choice for a small-scale work area since it’s not just a hot air rework station but also offers a soldering iron and bench power supply in one unit. But it was still just a little too long for his bench. The solution? Just run the thing through the bandsaw and cut it in half. Seriously.

Upon opening the 853D up, [EEpromChip] realized the internal layout wasn’t terribly efficient. There was plenty of extra room inside the case to begin with, but if the transformer was removed from the bottom of the case and mounted to the rear it would really cut down the device’s footprint.

After making sure he documented where everything connected, he took all the electronics out of the sheet metal case and cut it down to size on a bandsaw. He then reinstalled circuit boards, and this time mounted the beefy transformer so it hangs over the board rather than sits next to it. The end result is a version of the Kendal 853D which is several inches shorter than before with no impact on functionality.

Turning ~~closets~~ small spaces into dens of Hackerdom has been a topic we’ve discussed previously. Saving every inch is important if you ever hope to move into a grain silo or CNC’d plywood house.

Scotty Allen Builds A USB Drive From An IPhone

May 2, 2018 by Brian Benchoff 13 Comments

What happens when you come across a mysterious, partially populated circuit board in the Huaqiangbei electronics market in Shenzhen? If you’re [Scotty Allen], the only answer is to make your own USB drive from iPhone parts.

[Scotty] made a name for himself through his YouTube channel Strange Parts where he built his own iPhone from scratch, added a headphone jack to an iPhone, and other various exploits involving hot air in Shenzhen. This latest build is no different. It begins with a random PCB [Scotty] found at the electronics market. It has a USB port on one end, it has pads for an iPhone memory chip, and it has an IC that looks like a USB to Flash converter.

The build involved finding a few broken iPhones, desoldering and reballing their Flash chips, and when those didn’t work, finding the correct Flash chips for this tiny little USB adapter board. Here, [Scotty] ran into trouble. The first Flash chip didn’t have the right pins, there was blue smoke, and the toolchain for initializing the USB to Flash IC was a mess.

In the end, [Scotty] managed to create a USB Flash drive after five or six visits to the electronics market, two stencils to reball Flash chips, and finding the OEM software for the USB to Flash chip on this very special PCB. That, itself, required Windows (the horror!), and finding the right version of the software.

Is this technically building a Flash drive purely from disposed iPhone components? We’d quibble. But is it a cool build, regardless? Absolutely. And the real story here is how quickly [Scotty] could iterate on his engineering. When the greatest electronics market is right around the corner, you can do anything with a microscope and a hot air gun.