This Hackable Phone Makes WiFi Calls.

Over the years, we’ve seen dozens of projects that sell themselves as an ‘Open Source’ cellphone, a hackable cellphone, or some other confabulation of a microcontroller, screen, and a cellular module. The WiPhone is not one of these projects. That’s not to say it’s not an Open Source phone that’s intended to be hackable. No, this is a DIY phone that doesn’t make cellular calls, because this is a phone that only works with SIP and VoIP apps. It’s a WiPhone, and something a lot of us have been waiting for.

The hardware for this WiFi enabled phone is extremely minimal, but there are some interesting tricks up its sleeve. Instead of letting the main microcontroller handle capturing all the button presses, the team behind the WiPhone are using a SN7326 key-scan controller. This cheap part is able to scan 64 buttons, although there are only 25 buttons on the phone. The audio board is a  WM8750BL, a cheap codec with a stereo microphone interface and a 400 mW speaker driver. The display is a simple SPI TFT, and apart from the microcontroller, that’s about it.

But it’s the microcontroller that makes it, and for that we turn to the incredible ESP-32. This chip has enough power to play Doom, be a Game Boy, and in this case, make and receive calls from a VoIP provider, scan and connect to WiFi networks, and yes, it can even play snake.

While this is just about the simplest phone you can imagine, and it only works where there’s a WiFi network, a device like this could be invaluable. And really, these days how far are you from a WiFi network you’re already connected to anyway?

An Arduino Watch Without A Clock

When you show up at a party wearing this bare PCB watch, there are effectively two possible reactions you might receive from the other people there. Either they are going to snicker at the nerd who’s wearing a blinking circuit board on their wrist in public, or they are going to marvel at the ridiculously low part count. We’ll give you one guess as to which reaction you’d likely get at any event Hackaday is involved in.

Designed and built by [Electronoobs], this extremely simple watch consists of a ATmega328P microcontroller, a dozen LEDs with their associated 200 Ω resistors, and a battery. There’s also a single push button on the front which is used to not only set the watch, but turn the LEDs on when you want to check the time. Short of dropping down to one LED and blinking out the time, it’s hard to imagine a timepiece with fewer components than this.

You’re probably wondering how [Electronoobs] pulled this off without an external clock source for the ATmega328P chip. The chip actually has an internal 8 MHz oscillator that can be used, but you need to flash the appropriate bootloader to it first. Accordingly, the backside of the PCB has both SPI and a UART solder pads for external bootloader and firmware programming.

As you might expect, there’s a downside to using the internal oscillator: it’s not very good. The ATmega328P spec sheet claims a factory calibrated accuracy of ±10%, and [Electronoobs] has found that equates to a clock drift of around 15 seconds per day. Not exactly great, but considering the battery only lasts for two days anyway, it doesn’t have much of an impact in this case.

Compared to other “analog” LED watches we’ve seen, the simplicity of this build is really quite remarkable. The closest competitor we’ve seen so far is this slick binary watch.

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This Is Your Last Chance To Design The Greatest Human Computer Interface

This is your last chance to get your project together for the Human Computer Interface Challenge in this year’s Hackaday Prize. We’re looking for innovative interfaces for humans to talk to machines or machines to talk to humans. These are projects that make technology more intuitive, more fun, and a more natural activity. This is your time to shine, and we’re accepting entries in the Human Computer Interface Challenge in this year’s Hackaday Prize until August 27th. This is your last weekend to work on your project, folks.

This is one of the best years of the Hackaday Prize yet, with almost one thousand projects vying for the top prize of $50,000 USD. That doesn’t mean everyone else is going home empty handed; we’ve already awarded $1000 prizes to twenty projects in each of the first three challenges, and this coming Monday, we’ll be figuring out the winners to the Human Computer Interface challenge. Twenty of those finalists will be awarded $1000 USD, and move onto the final round where they’re up for the Grand Prize.

Don’t miss your last chance to get in on the Human Computer Interface Challenge in this year’s Hackaday Prize. We’re looking for an interface that could be visual, auditory, haptic, olfactory, or something never before imagined. We’re sure we’re going to see an Alexa duct taped to a drone, and that’s awesome. We’re taking all comers. Don’t wait — start your entry now.

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How To Mash Up BLE, NodeJS, And MQTT To Get Internet Of Things

We’re living in the world of connected devices. It has never been easier to roll your own and implement the functionality you actually want, rather than live with the lowest common denominator that the manufacture chose.

In a previous article I walked though a small python script to talk to a BLE light and used it to cycle through some colors. Now I want to delve deeper into the world of Internet Connected BLE devices and how to set up a simple Internet-Of-Things light. With this example in hand the sky’s the limit on what you can build and what it will be able to do.

Join me after the break as I demonstrate how to use NodeJS to bridge the digital world with the physical world.

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Power Over Ethernet Splitter Improves Negotiating Skills

Implementing PoE is made interesting by the fact that not every Ethernet device wants power; if you start dumping power onto any device that’s connected, you’re going to break things. The IEEE 802.3af standard states that the device which can source power should detect the presence of the device receiving power, before negotiating the power level. Only once this process is complete can the power sourcing device give its full supply. Of course, this requires the burden of smarts, meaning that there are many cheap devices available which simply send power regardless of what’s plugged in (passive PoE).

[Jason Gin] has taken an old, cheap passive PoE splitter and upgraded it to be 802.3af compatible (an active device). The splitter was designed to be paired with a passive injector and therefore did not work with Jason’s active 802.3at infrastructure.

The brain of the upgrade is a TI TPS2378 Powered Device controller, which does the power negotiation. It sits on one of two new boards, with a rudimentary heatsink provided by some solar cell tab wire. The second board comprises the power interface, and consists of dual Schottky bridges as well a 58-volt TVS diode to deal with any voltage spikes due to cable inductance. The Ethernet transformer shown in the diagram above was salvaged from a dead Macbook and, after some enamel scraping and fiddly soldering, it was fit for purpose. For a deeper dive on Ethernet transformers and their hacked capabilities, [Jenny List] wrote a piece specifically focusing on Raspberry Pi hardware.

[Jason]’s modifications were able to fit in the original box, and the device successfully integrated with his 802.3at setup. We love [Jason]’s work and have previously written about his eMMC adventures, repairing windows tablets and explaining the intricacies of SD card interfacing.

Two Bit Circus Took The Tech We Love And Built An Amusement Park

Carnival games are simple to pick up, designed to provide a little bit of entertainment in exchange for your game ticket. Given that the main point is just to have some silly fun with your friends, most game vendors have little reason to innovate. But we are people who play with microcontrollers and gratuitous LEDs. We look at these games and imagine bringing them into the 21st century. Well, there’s good news: the people of Two Bit Circus have been working along these lines, and they’re getting ready to invite the whole world to come and play with them.

“Interactive Entertainment” is how Two Bit Circus describe what they do, by employing the kinds of technology that frequent pages of Hackaday. But while we love hacks for their own sake here, Two Bit Circus applies them to amuse and engage everyone regardless of their technical knowledge. For the past few years they’ve been building on behalf of others for events like trade shows and private parties. Then they worked to put together their own event, a STEAM Carnival to spread love of technology, art, and fun. The problem? They are only temporary and for a limited audience, hence the desire for a permanent facility open to the public. Your Hackaday scribe had the opportunity to take a peek as they were putting on the finishing touches.

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Fail Of The Week: Solid State Relay Fails Spectacularly

A lot of times these days, it seems like we hackers are a little like kids in a candy store. With so many cool devices available for pennies at the click of a mouse, it’s temptingly easy to order first and ask questions about quality later. Most of the time that works out just fine, with the main risk of sourcing a dodgy component being a ruined afternoon of hacking when a part fails.

The stakes are much higher when you’re connecting your project to the house mains, though, as [Mattias Wandel] recently learned when the solid-state relay controlling his water heater failed, with nearly tragic results. With aplomb that defies the fact that he just discovered that he nearly burned his house down, [Mattias] tours the scene of the crime and delivers a postmortem of the victim, a Fotek SSR-25DA. It appears that he mounted it well and gave it a decent heatsink, but the thing immolated itself just the same. The only remnant of the relay’s PCB left intact was the triac mounted to the rear plate. [Mattias] suspects the PCB traces heated up when he returned from vacation and the water heater it was controlling came on; with a tank full of cold water, both elements were needed and enough current was drawn to melt the solder build-up on the high-voltage traces. With the solder gone, the traces cooked off, and the rest is history. It’s a scary scenario that’s worth looking at if you’ve got any SSRs controlling loads anywhere near their rated limit.

The morals of the story: buy quality components and test them if possible; when in doubt, derate; and make sure a flaming component can’t light anything else on fire. And you’ll want to review the basics of fire protection while you’re at it.

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