Glowtie Is Perfect For Those Fancy Dress Raves

February 25, 2019 by Tom Nardi 3 Comments

Are you bored of your traditional bow tie? Do you wish it had RGB LEDs, WiFi, and a web interface that you could access from your smartphone? If you’re like us at Hackaday…maybe not. But that hasn’t stopped [Stephen Hawes] from creating the Glowtie, an admittedly very slick piece of open source electronic neckwear that you can build yourself or even purchase as an assembled unit. Truly we’re living in the future.

While we’re hardly experts on fashion around these parts (please see the “About” page for evidence), we can absolutely appreciate the amount of time and effort [Stephen] has put into its design. Especially considering his decision to release the hardware and software as open source while still putting the device up on Kickstarter. We seen far too many Kickstarters promising to open the source up after they get the money, so we’re always glad to see a project that’s willing to put everything out there from the start.

For the hardware, [Stephen] has gone with the ever popular ESP8266 module and an array of WS2812B LEDs around the edge of the PCB. There’s also a tiny power switch on the bottom, and a USB port for charging the two 1S 300mAh lipo batteries on the backside of the Glowtie. The 3D printed rear panel gives the board some support, and features an integrated bracket that allows it to clip onto the top button of your shirt. For those that aren’t necessarily a fan of the bare PCB look or blinding people with exposed LEDs, there’s a cloth panel that covers the front of the Glowtie to not only diffuse the light but make it look a bit more like a real tie.

To control the Glowtie, the user just needs to connect their smartphone to the device’s WiFi access point and use the web-based interface. The user can change the color and brightness of the LEDs, as well as select from different pre-loaded flashing and fading patterns. The end result, especially with the cloth diffuser, really does look gorgeous. Even if this isn’t the kind of thing you’d wear on a daily basis, we have no doubt that you’ll be getting plenty of attention every time you clip it on.

It should be said that [Stephen] is no stranger to wearable technology. We’ve previously covered his mildly terrifying wrist mounted flamethrower, so if he managed to build that without blowing himself up, we imagine building a light up tie should be a piece of cake in comparison.

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Get Twelve Charlieplexed PWM Outputs From An ATtiny85

February 24, 2019 by Donald Papp 8 Comments

Most of us are aware that charlieplexing can drive a large number of LEDs from a relatively small number of I/O pins, but [David Johnson-Davies] demonstrates adding another dimension to that method to create individually controlled PWM outputs as well. His ATtiny85 has twelve LEDs, each with individually-set brightness levels, and uses only four of the five I/O pins on the device.

Each LED can be assigned a brightness between 0 (fully off) and 63 (fully on). The PWM is done by using one of the timers in the ATtiny85 to generate a periodic interrupt, and the ISR for the interrupt takes care of setting the necessary ratios of on and off times for each charlieplexed output. The result? Twelve flicker-free LEDs with individually addressable brightness levels, using an 8-pin microcontroller and just a few passive components on a tiny breadboard. There’s even one I/O pin left on the ATtiny85, for accepting commands or reading a sensor.

[David] really wrings a lot out of the ATtiny series of microcontrollers with his compact projects, like his Tiny Function Generator (which recently got an update.) He also demonstrated that while charlieplexing is usually used with LEDs, charlieplexing can be used with switches just as easily.

A Coin Cell Powers This Tiny ESP32 Dev Board

February 22, 2019 by Dan Maloney 27 Comments

Just for the challenge, just for fun, just for bragging rights, and just to do a little showing off – all perfectly valid reasons to take on a project. It seems like one or more of those are behind this tiny ESP32 board that’s barely larger than the coin cell that powers it.

From the video below, [Mike Rankin] has been working down the scale in terms of powering and sizing his ESP32 builds. He recently completed a project with an ESP32 Pico D4 and an OLED display that fits exactly on an AA battery holder, which he populated with a rechargeable 14550. Not satisfied with that form factor, he designed another board, this time barely larger than the LIR2450 rechargeable coin cell in its battery holder. In addition to the Pico D4, the board sports a USB charging and programming socket, a low drop-out (LDO) voltage regulator, an accelerometer, a tiny RGB LED, and a 96×16 OLED display. Rather than claim real estate for switches, [Mike] chose to add a pair of pads to the back of the board and use them as capacitive touch sensors. We found that bit very clever.

Sadly, the board doesn’t do much – yet – but that doesn’t mean we’re not impressed. And [Mike]’s no stranger to miniaturization projects, of course; last year’s Open Hardware Summit badge was his brainchild.

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Talking Telegram With The ESP8266

February 21, 2019 by Tom Nardi 5 Comments

At this point it’s something of a given that a member of the ESP8266 family is likely your best bet if you want to cobble together a small Internet-connected gadget. Costing as little as $3 USD, this well documented all-in-one solution really can’t be beat. But of course, the hardware is only one half of the equation. Deciding how to handle the software side of your homebrew Internet of Things device is another story entirely.

It would be fair to say that there’s no clear-cut “right” way to approach the software, and it really depends on the needs or limitations of your particular project. For example [Brian Lough] finds that building Telegram support into his ESP8266 allows him to accomplish his goals with the minimum amount of fuss while at the same time using an environment he’s already comfortable with. He recently wrote in to share one of his Telegram projects with us, and in the video after the break, takes the time to explain some of the things he likes best about controlling his hardware through the encrypted chat platform.

But you don’t have to take his word for it, you can try it yourself. Thanks to the software library that [Brian] has developed to connect his projects to Telegram, the aptly named “Universal Telegram Bot Library”, anyone can easily follow in his footsteps. Adding his Telegram library to your next ESP8266 project is as easy as selecting it in the Arduino IDE. From there the video explains the process for getting a bot ID from Telegram, and ultimately how you use it to receive messages from the service. What you do with those messages is entirely up to you.

According to [Brian], the main downside is that you are beholden to a web service to control your local devices; not ideal if the Internet goes down or you would rather your little hacker projects not talk to the big scary Internet in the first place. If you’d rather keep all your smart things talking within the confines of your own network, perhaps your next project could be setting up a private MQTT server.

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Badge.Team: Badges Get A Platform

February 20, 2019 by Jenny List 21 Comments

Electronic conference badges are now an accepted part of the lifeblood of our community, with even the simplest of events now sporting a fully functional computer as an eye-catching PCB on a lanyard. Event schedules and applications are shipped on them, and the more sophisticated ones have app libraries and support development communities of their own.

The trouble is that so often those badges fail to live up to their promise, and one reason behind that stems from the enormity of the task facing a badge team when it comes to firmware for a modern badge. There is some fascinating news from the Netherlands that might reduce some of those firmware woes though, badge.team is a freshly-launched project that provides a ready-made badge firmware with the promise of both stability and long-term support. If you’re making a badge, or even a one-off device using the ESP32, this is a project worth checking out.

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How To Program A Really Cheap Microcontroller

February 17, 2019 by Brian Benchoff 60 Comments

There are rumors of a cheap chip that does USB natively, has an Open Source toolchain, and costs a quarter. These aren’t rumors: you can buy the CH552 microcontroller right now. Surprisingly, there aren’t many people picking up this cheap chip for their next project. If there’s no original projects using this chip, no one is going to use this chip. Catch 22, and all that.

Like a generous god, [Aaron Christophel] has got your back with a working example of programming this cheap chip, and doing something useful with it. It blinks LEDs, it writes to an I2C display, and it does everything you would want from a microcontroller that costs a few dimes.

The CH552, and its friends the small CH551 all the way up to the CH559, contain an 8051 core, somewhere around 16 kB of flash, the high-end chips have a USB controller, there’s SPI, PWM, I2C, and it costs pennies. Unlike so many other chips out there, you can find SDKs and toolchains. You can program the chip over USB. Clearly, we’re looking at something really cool if someone writes an Arduino wrapper for it. We’re not there yet, but we’re close.

To program these chips, [Aaron] first had to wire up the microcontroller into a circuit. This was just a bit of perf board, a resistor, a few caps, and a USB A plug. That’s it, that’s all that’s needed. This is a fairly standard 8051 core, so writing the code is relatively easy. Uploading is done with the WCHISPTool software, with options available for your favorite flavor of *nix.

But it gets better. One of the big features of the CH552 is USB. That means no expensive or weird programmers, yes, but it also means the CH552 can emulate a USB HID device. The CH552 can become a USB keyboard. To demo this, [Aaron] programmed a CH552 board (DE, here’s the Google translatrix) loaded up with touch pads and LEDs to become a USB keyboard.

If you don’t feel like soldering up one of these yourself, there are some suppliers of CH554 dev boards, and the files for [Aaron]’s projects are available here. Check out the videos below, because this is the best tutorial yet on programming and using some very interesting chips that just appeared on the market.

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A Lightweight AVR IDE

February 17, 2019 by Lewin Day 11 Comments

It’s entirely possible to do your coding in vim or emacs, hammering out hotkeys to drive the interface and bring your code to life. While working in such a way has its charms, it can be confronting to new coders, and that’s before even considering trying to understand command line compiler settings. The greenhorn coder may find themselves more at home in the warm embrace of an IDE, and [morrows_end] has now built one for those working with AVR assembly code.

The IDE goes by the name of Simple AVR IDE, or savr_ide for short. Programmed in C++ with the FLTK widget library, [morrows_end] has tested it on Windows XP, but notes that it should successfully compile for Linux, Unix, and even MacOS too.

All the basic features are there – there’s syntax highlighting, as well as integration with the AVRA assembler and AVRDUDE for programming chips. It’s a tool that could make taking the leap into assembly code just that little bit easier. For another taste of bare metal coding, check out [Ben Jojo]’s discussion of x86 bootloaders.