Sound-Triggered Eye Protection For The Forgetful Among US

Eyes are fragile things. They tend to fail under extreme heat, pressure, and are easily damaged by flying objects. Enterprising humans have developed a wide range of eye protection solutions, but most only work when the user remembers to put them on. [gocivici] had just such a problem, forgetting to put his safety glasses back on when working. Naturally, the solution was found through hacking.

The build starts with a regular baseball cap. [gocivici] fitted an Arduino nano, which is connected to a small microphone. The Arduino uses the microphone to determine the sound level in the room. Above a certain trigger level, the Arduino triggers a servo to move protective glasses into place in front of the wearer’s eyes, protecting them from flying shrapnel from whatever they may be working on.

It’s a fun build, that obviously still has the pitfall that you’re going to get hurt if you forget to wear your magic hat for the day. Another approach could be putting your multimeter display in your goggles so you never want to take them off in the first place. Video after the break.

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A Drum Set In Your Pocket

Cargo pants can fit drumsticks in the pockets if you don’t mind them sticking out. They can also hold this drum set and still have enough room for a pair of headphones, some pens, and a small notebook. At least, guy’s cargo pants can fit all that. Now your pocket is decked out with enough music gear to compose and drum few drum loops and even scribble some notes. We can’t speak for [Tomash Ghz] carrying a notebook, but he wanted a drum set in his pocket badly enough to make a custom circuit board to bring to the 2017 Fasma Festival in Athens. He wrote code for a Teensy 3.2 which fits on the back of his PCB next to a 9V battery. Don’t be afraid, the smallest components are 0805 so even clumsy fingers will be able to build their own. The Gerber files and BOM are all available, so nothing is stopping you.

On the board, we find an array of op-amps to support headphone and line-level outputs, four big ole’ buttons to activate each type of drum: kick, tom, snare, and hat. Then we have four potentiometers to change the sound of each like pitch, decay/length, modulation, and distortion. Once the perfect pattern is recorded, it can be saved in non-volatile memory in case you run out of juice although it can run up to seven-and-a-half hours on one battery. If you find yourself invested in the hardware, there is also a video walk-through about using the drum machine so grab your notebook and beat it.

We have seen simpler drums in simpler chips, and even drums on an entirely different type of chip.

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A Gif-Playing Top Hat For FRC 2018!

In gearing up to mentor a team at the 2018 FIRST Robotics Competition, redditor [dd0626] wanted to do something cool that resonated with this year’s 8-bit gaming theme. Over the course of a few days, they transformed a top hat into a thematically encapsulating marquee: a LED matrix display loaded with gifs!

The display is actually a sleeve — made from shipping foam, a pillow case, and an old t-shirt — that fits over the hat, leaving it intact and wearable for future events. A Teensy3.6 displays the gifs on four WS2812 16×16 RGB LED matrices, and while a sheer black fabric diffuses the light, it’s still best viewed from several feet away. This is decidedly not intended to be a stealthy hat display.

To mitigate current draw, [dd0626] is using a 5V 30A DC/DC converter and keeping the brightness at a minimum — otherwise, each panel can pull up to 15A! To offset any dip in performance, they’ve bundled in a massive 22,400mAh, 24V battery pack to keep the hat running for a while. Despite all the hardware, the hat weighs under two pounds — eminently wearable for a long day of competition. Continue reading “A Gif-Playing Top Hat For FRC 2018!”

Astro Cat: Raspberry Pi Telescope Controller

When somebody tackles an engineering problem, there are two possible paths: they can throw together a quick and dirty fix that fits their needs (the classic “hack”, as it were), or they can go the extra mile to develop a well documented solution that helps the community as a whole. We cover it all here at Hackaday, but we’ve certainly got a soft spot for the latter approach, even if some may feel it falls into the dreaded territory of “Not A Hack”.

When [Gary Preston] wanted to control his telescope and astrophotography hardware, he took the second path in a big way. Over the course of several posts on his blog, [Gary] walks us though the creation of his open source Raspberry Pi add-on board that controls a laundry list of sensors and optical gear. Just don’t call it a HAT, while it may look the part, [Gary] is very specific that it does not officially meet the HAT specifications put out by the Raspberry Pi Foundation.

Even if you aren’t terribly interested in peering into the infinite void above, the extremely detailed write-up [Gary] has done contains tons of multidisciplinary information that you may find useful. From showing how to modify the Pi’s boot configuration to enable true hardware UART (by default, the Pi 3 ties it up with Bluetooth) and level shifting it with a ST3232 to a breakdown of the mistakes he made in his PCB layout, there’s plenty to learn.

Astro CAT is a completely open source project, with the hardware side released under the CERN Open Hardware License v1.2, and the INDI driver component is available under the GPL v3.

If this looks a bit daunting for your first stab at astrophotography with the Raspberry Pi, fear not. We’ve covered builds which can get you up and running no matter what your budget or experience level is.

8-Channel ADC For the Raspberry Pi

The Raspberry Pi is a powerful embedded computing platform. However, for all its Linux-based muscle, it lacks one thing that even the simplest 8-bit microcontrollers usually have – analog-to-digital conversion. There are a great many ways to rectify this shortcoming, and [Chris Burgess] has brought us another – with an 8-channel ADC for the Raspberry Pi.

For the ADC, [Chris] chose the MCP3008, for its low cost and availability. In this configuration it offers 10-bit resolution and a maximum sampling rate of 200 kilosamples per second. Adafruit has a great guide on working with the MCP3008, too. With such a useful resource to hand, [Chris] was able to spin up a PCB to interface the chip to the Raspberry Pi using SPI. [Chris] took care to try to make the board to the official HAT specifications. As far as the physical aspects go, the board is to spec, however [Chris] omitted the EEPROM required for auto-configuration purposes. That said, the pads are on the board if someone wants to take the initiative to install one.

It’s a tidy build that provides something sorely missing from the Raspberry Pi, for a reasonable cost. [Chris]’s goal was to build something that would enable the measurement of analog sensors for a robot project; we’d love to hear your ideas for potential uses in the comments!

Old Intercom Gets Googled with Raspberry Pi and AIY Hat

Old Radio Shack intercom; brand new Google Voice interface for a Raspberry Pi. One of these things is not like the other, but they ended up together in this retro-look Google Voice interface, and the results are pretty slick.

The recipient of the Google hive-mind transplant was one of three wireless FM intercoms [MisterM] scored for a measly £4. Looking much as they did when they were the must-have office tool or home accessory for your modern mid-80s lifestyle, the intercom case was the perfect host for the Pi and the Google AIY hat. Only the case was used — not even the original speaker made it into the finished product. The case got a good scrubbing, a fresh coat of paint to perk up the gone-green plastic, and an accent strip of Google’s logo colors over the now-deprecated station selector switch. [MisterM] provided a white LED behind the speaker grille for subtle feedback. A tap of the original talk bar gets Google’s attention for answers to quick questions, and integration into the family’s existing home automation platform turns the lights on and off. See it in action after the break.

[MisterM] was lucky enough to score an AIY hat for free, and as far as we know they’re still hard to come by. If you’re itching to try out the board, fear not — turns out you can roll your own.

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3.3V Is Not Enough for This Raspberry Pi Zero

A Raspberry Pi Zero is down to a price and size where it’s just begging to be integrated into your projects. Unless, that is, if your project involves a lot of 5 V equipment. Then it’s just begging to be fried.

[David Brown] solved this problem by breaking out pins with level converters. He used flat-flex cable and some pin-headers. While he was at it, he added a full-sized USB port and power headers. (Extra hack points are awarded for connecting the USB to the board through pogo pins.)

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