There are a few different ways of getting firmware onto one of AVR’s ATtiny85 microcontrollers, including bootloaders that allow for firmware to be updated without the need to plug the chip into a programmer. However, [casanovg] wasn’t satisfied with those so he sent us a tip letting us know he wrote an I2C bootloader for the ATtiny85 called Timonel. It takes into account a few particulars of the part, such as the fact that it lacks a protected memory area where a bootloader would normally reside, and it doesn’t have a native I2C interface, only the USI (Universal Serial Interface). He’s just released the first functional version for the ATtiny85, but there’s no reason it couldn’t be made to work with the ATtiny45 and ATtiny25 as well.
Timonel is designed for systems where there is a more powerful microcontroller or microprocessor running the show (such as an ESP8266, Arduino, or even a board like a Raspberry Pi.) In designs where the ATtinys are on an I2C bus performing peripheral functions such as running sensors, Timonel allows the firmware for these peripheral MCUs to be updated directly from the I2C bus master. Embedded below is a video demo of [casanovg] sending simple serial commands, showing a successful firmware update of an AVR ATtiny85 over I2C.
Electromechanical solenoids are pretty cool devices. Move some current through an electromagnet and you can push a load around or pull it. If you’re MIT student [Lining Yao], you can use them to dance. [Lining] built TapBot, a re-configurable set of tap-dancing robots that are both modular and modern. She even rolled her own solenoids.
The one with the eye stalk is the bridge, and it’s connected to a computer over FTDI. The other nodes attach to the bridge and each other with small magnets that are designed to flip around freely to make the connections. These links are just physical, though. The nodes must also be connected with ribbon cables.
Each of the nodes is controlled by an ATtiny45 and has a MOSFET to drive the solenoid at 8-12 V. [Lining] snapped a small coin magnet to the end of each solenoid slug to provide a bigger surface area that acts like a tap shoe. TapBot can be programmed with one of several pre-built tap patterns, and these can be combined to make new sequences. The curtain goes up after the break.
You think you’ve seen everything that there is to see regarding blinking LEDs and then a simple little trick proves you wrong. Our friend [Zach Fredin], aka [Zakqwy], added a pander mode to his blinky board which shows the Hackaday Jolly Wrencher in a Persistence of Vision mode. We love pandering, and obviously you just need to start the mode and wave the board back and forth. But in thinking the obvious you’d be wrong.
You would think that soldering all those LEDs by hand would be the trick, but [Zach] pulled off a much more difficult feat. Look closely at the image here (or click to embiggen). The two shift register footprints on the prototype were mirrored. He deadbug soldered each of them using — get this — the individual strands from some 28 AWG stranded wire. You sir, get the hardcore hand soldering badge and then some.
Okay, we’ll stop beating around the bush. The ATtiny45 on this board isn’t connected to the USB data lines, they’re only for power. That means, at its heart this is purely a blinking LED project, albeit one that uses the huge range of colors of the PICOLED family of parts. [Zach] did well with just two user inputs, but it’s the very simple POV party trick that really sucked us in. Instead of waving the board around, [Zach] uses a metal offset spatula as a mirror. Moving it back and forth unfolds the carefully timed flashes to draw your message in the air. Such a simple concept, but so satisfying to see it applied in a slightly different way.
Today is a very special day for [Mandy and Sebastian], as they conclude the sacred solder joint of marriage. We send our sincerest congratulations and best wishes to the bridal couple, and can’t help but envy the guests of their ceremony, who received a very special wedding favor: A WeddingBot.
For their wedding party, [Mandy and Sebastian] created a little game on their own (translated). Each guest would receive a unique, little WeddingBot. Each of these is individually tailored for a certain guest and features a fitting look, a characteristic behavior and would play a special melody or jingle meaningful to this guest. However, the guests don’t get their WeddingBot, they get the WeddingBot of another guest – and the challenge to find this guest on the party. Guests would then exchange their WeddingBots, which also makes a great occasion to introduce themselves to each other. If the clues given by the WeddingBots themselves would not suffice to find the right owner, guest could place a WeddingBot on a clue station, which then would provide further hints by displaying images, texts or even riddles.
The design is based on the ATtiny45 microcontroller, with LEDs for the eyes, a light sensor, and a piezo disc for the sound as the main components. As an enclosure, they chose to repurpose empty Nespresso® capsules, which look nice and adds volume to the PCBs. The smiley face silk screen on the PCBs was then individualized with a black marker and packed in a beautiful hand-crafted box. The little fellows communicate with the Raspberry Pi based clue station by flashing their LEDs in a certain pattern. A light sensor hooked up to the Pi lets the station identify the bot and display the corresponding clue on a screen. Check out the video below to see how it works:
Over on Hackaday.io, there’s an unofficial contest to cram as much electronics and awesome as possible into a single square inch of PCB. While the measurement system is logical, the Internet is not: it feeds on cats and is entertained by rainbows. [Radomir]’s project feeds into this bizarre fixation with the Nyan Board, a Pop Tart cat that poops rainbows, all the while playing bleeps and boops that would fit well in a Nintendo game.
[Radomir] built this square inch of twee for the square inch project, an unofficial contest to fit the coolest project on a 1×1 inch square PCB. Prizes are credits for the Hackaday Store and OSHPark. This entry uses an ATtiny85 microcontroller, a few resistors, LEDs, and a buzzer to play the strange, syncopated Nyan theme song. Power is delivered over a colorful ribbon cable that emulates the rainbow tail of the Pop Tart cat.
We can commiserate with [HardwareCoder] who would rather not leave his PC speakers on all the time. The Creative T20 set that he uses turn off when you turn the volume knob all the way down until it clicks. So shutting them off means repositioning the volume each time they’re switched on again. This hack kills two birds with one stone by turning on and off automatically without touching that knob.
The system is based around an ATtiny45 and a few other simple components. It uses two ADCs to monitor the rear input channels of the PC speakers. If no sound is detected for more than one minute, the shutdown pin of the speakers’ amp chip is triggered. That’s not quite where the hack ends. We mentioned it monitors the rear input of the speakers, but it doesn’t monitor the front AUX input. An additional push button is used to disable the auto-sleep when using this front input. There is also a fancy PWM-based heartbeat on an LED when the speakers are sleeping.
[HardwareCoder] was worried that we wouldn’t be interested in this since it’s quite similar to a hack we ran a few years ago. We hope you’ll agree it’s worth another look. He also warned us that the demo video was boring. We watched it all anyway and can confirm that there’s not much action there but we embedded it below anyway.