switch

94 Articles

Reverse Engineering Self-Powered Wireless Switches

May 2, 2021 by 29 Comments

The plethora of wireless communications technologies have cut the comms wire for many applications, but these devices still require power. For home automation, this might mean a battery or mains power, but there is also an alternative that we don’t see often: Kinetic power. [Bigclivecom] bought some kinetic switches from eBay and gave it his usual reverse engineering treatment.

True to the marketing, these switches do not require external power or a battery to send a wireless signal. Instead, it harvests energy from the magnetic latching action of the switch itself. When the switch is actuated, a small current is induced in a coil as the polarity of the magnetic field through its core changes rapidly. Through a series of diodes and resisters, the energy is stored in a capacitor, which is then used to power a small transmitter chip. The antenna coil is wrapped around the switch housing.

The receiver side is powered by mains and includes a relay output for lights. It would be really nice to have a hacker-friendly module for projects. We would be curious to see the range that these devices are capable of.

The same technology is used inside the Philips Hue Tap switch, of which Adafruit did a teardown a few years ago. If you want to learn more about RF modulation, check out the crash course article we put out a while back. Of course, the RTL SDR is an indispensable and affordable tool if you want to do some experimentation.

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Python Will Soon Support Switch Statements

April 2, 2021 by 113 Comments

Rejoice! Gone are the long chains of if…else statements, because switch statements will soon be here — sort of. What the Python gods are actually giving us are match statements. match statements are awfully similar to switch statements, but have a few really cool and unique features, which I’ll attempt to illustrate below.

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This Joy-Con Grip Steers Its Way To Sweaty Victory

February 8, 2021 by No comments

Here at Hackaday we’re always exited to see hacks that recycle our favorite childhood consoles into something new and interesting. In that context, it’s not so uncommon to see mods which combine new and unusual control methods with old devices in ways that their manufacturers never intended. What [Mike Choi] has built with the Labo Fit Adventure Kit is the rare hack that combines radically new control schemes with a modern console: without actually modifying any hardware.

Face button pusher in blue

In short, the Labo Fit Adventure Kit lets the player play Mario Kart on the Nintendo Switch by riding a stationary exercise bike, steering with a wheel, and squeezing that wheel to use items. The Fit Kit combines the theme of Labo, Nintendo’s excellent cardboard building kit for the Nintendo Switch with the existing Ring-Con accessory for the unrelated Nintendo game Ring Fit Adventure plus a collection of custom hardware to tie it all together. That hardware senses cadence on the stationary bike, watches for the user to squeeze the handheld wheel controller, and translates those inputs to button presses on the controller to play the game.

Shoulder button pusher in green

The most fascinating element of this project is the TAPBO module which adapts the Joy-Con controller to remote input. The module includes electronics, actuators, and a clever mechanical design to allow it to be mounted to the Ring-Con in place of an unmodified Joy-Con. Electrically the components will be familiar to regular Hackaday readers; there is a breakout board for a Teensy which also holds an XBee module to receive inputs remotely and drive a pair of servos. The entire module is described in detail starting at 4:42 in the video.

Mechanically the TAPBO relies on a pair of cam-actuated arms which translate rotational servo motion into linear action to press shoulder or face buttons. The module directly measures flex of the Ring-Con with an added flexible resistor and receives cadence information from another module embedded in the stationary bike via Zigbee. When these inputs exceed set thresholds they drive the servos to press the appropriate controller buttons to accelerate or use an item.

We’ve focused pretty heavily on the technical aspects of this project, but this significantly undersells the level of polish and easy to understand documentation [Mike] has produced. It includes a TAPBO Amiibo in customized packaging, and more. Check out the full video to get the complete scope of this project.

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Tiny Ethernet Routers Now Available In Gigabit Speeds

November 26, 2020 by 63 Comments

If you need to move a lot of data, and fast, Gigabit Ethernet is a great way to do it. However, most network hardware outside of datacenters is fairly space inefficient, a headache if you’re building a robot or drone. Enter the Gigablox, a super-compact Gigabit router for just these applications.

The Gigablox takes its mission seriously, with its compact size the ultimate design goal. The entire switch fits on a tiny 45 mm x 45 mm PCB. To this end, it eschews the common RJ45 connector, which is bulkier than necessary. Instead, thin Molex PicoBlade connectors are used for the five ports on board. Cables are included to convert between the two connectors, and obviously crimping ones own is easy to do, too. For those who need to connect more devices, several Gigablox can be hooked up in the same way as any other Ethernet switch. The Gigablox is a non-blocking switch, too – meaning all five ports can run at full speed simultaneously.

The design is the sequel to the SwitchBlox, and the later SwitchBlox Nano, both designed by [Josh Elijah] earlier this year. The pace of development is impressive, and it’s great to see [Josh] bring Gigabit speeds to the compact form factor. We can imagine a few good uses for these boards; share your best ideas in the comments below! Video after the break.

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DIY Relay Module Saves Time

September 6, 2020 by 22 Comments

As any programmer could tell you, there’s significant value in automating a process that is performed often enough. The more times that process is used, the more it makes sense to automate it or at least improve its efficiency. This rule isn’t limited to software though; improvements to hardware design can also see improvements in efficiency as well. For that reason, [Hulk] designed a simple relay module in order to cut the amount of time he spends implementing this solution in his various other projects.

While driving a relay with a transistor is something fundamental, this project isn’t really about that per se. It’s about recognizing something that you do too much, and then designing that drudgery out of your projects. [Hulk] was able to design a PCB with 12 modules on it, presumably saving fabrication costs. He can then easily populate them with specific components as soon as he needs one. Another benefit of designing something like this yourself, rather than an off-the-shelf relay module, is that you can do away with any useless features you’ll never need (or add ones that aren’t available in commercial devices).

We can appreciate the efficiency gains this would make for our next project that needs a simple driver for a light, garage door opener, or any other binary electronic device. It can be a hassle to go find the correct transistor and relay, solder it all on the project board, and hope it all works. A pre-made solution solves all these issues, but we do wish the schematics were available to keep us from having to design our own. Driver boards are a pretty common project for all the different types of relays we see around here, so there is probably one available out there.

Tiny Ethernet Switch Gets Even Smaller

July 23, 2020 by 41 Comments

As a project gets more complicated, some kind of internal communication network is often used to that all of the various modules and sensors can talk with each other. For hardware hackers like us, that usually means SPI, I2C, or maybe even good old fashioned UART. But if you’re pushing a lot of data around, like live video feeds from multiple cameras, you’ll need something a bit faster than that.

Which is why [Josh Elijah] has created the SwitchBlox Nano, a three port 10/100 Ethernet switch that fits on a one inch square PCB. All you need to do is provide it with power, with a generous input range of 5 to 50 volts, connect your devices to the Molex Picoblade connectors on the board, and away you go. There’s even a 5 V 1 A regulated output you can use to run your downstream devices.

If you’ve got a feeling that you’ve seen something very similar on these pages earlier in the year, you’re not imagining things. Back in April we covered the original five port SwitchBlox in a post that garnered quite a bit of attention. In fact, [Josh] tells us that the design of this new switch was driven largely by the feedback he got from Hackaday readers. The Nano is not only smaller and cheaper than the original, but now maintains full electrical isolation between each port.

The average Hackaday reader is as knowledgeable as they are opinionated, and we’re glad [Josh] was able to put the feedback he received to practical use. We’re proud that our community has had a hand in refining successful commercial products like the Arduboy handheld game system and the Mooltipass hardware password keeper. Now it looks like we can add a tiny Ethernet switch to the list of gadgets we’ve helped push up the hill. Maybe we should get a stamp or something…