Hackaday Prize Entry: LiFePO4wered/Pi+

For some of you the title might seem familiar, as [Patrick Van Oosterwijck] LiFePO4wered/Pi project is a quite successful Hackaday.io project. Now he’s designing from scratch the plus version to fill in some gaps and solve some of the challenges that affected the initial project. So what exactly is LiFePO4wered/Pi+ and what can it do?

In a nutshell, it’s a smart UPS for the Raspberry Pi. The standard version allows a Model A+ and Pi Zero to run on battery for over 2 hours, and the B+, B2 and B3 to run for at least an hour (it maybe less, depending on the system load, of course). It implements two-way communications between the power system and the Raspberry Pi (running the open-source daemon) over the I2C bus. This allows for continuous measurement of the battery voltage and load voltage, with user programmable thresholds for boot, clean shutdown and hard power down. There’s a touch pad that provides clean boot/shutdown capability even in a headless setup, a wake timer allowing the Raspberry Pi to be off for low duty cycle applications and an auto-boot feature to maximize uptime by making the Raspberry Pi run whenever there is sufficient battery power.

That’s the standard version, which we covered last year… what else could the plus version have?

Well, to start, it brings more current to run complete systems with LCD screen and hard drives, the previous version was limited when it came to current. It will provide the option for a wider range of input power sources, such as solar panels, which is pretty nice. The on/off button and the power led will no longer be soldered on the main board so they can ‘relocated’ elsewhere, for example, when making a custom enclosure. Detection of input power to trigger automatic boot and shutdown will be added and last, but not least, a real-time clock with absolute time wake up.

So there it is, the new LiFePO4wered/Pi+ version, with all bells and whistles for the Raspberry Pi enthusiast.

Hackaday Prize Entry: Rangefinder + Camera = SmartZoom

The interesting thing about submissions for The Hackaday Prize is seeing unusual projects and concepts that might not otherwise pop up. [ken conrad] has a curious but thoughtfully designed idea for Raspberry Pi-based SmartZoom Imaging that uses a Pi Zero and camera plus some laser emitters to create a device with a very specific capability: a camera that constantly and dynamically resizes the image make the subject appear consistently framed and sized, regardless of its distance from the lens. The idea brings together two separate functions: rangefinding and automated zooming and re-sampling of the camera image.

The Raspberry Pi uses the camera board plus some forward-pointing laser dots as a rangefinder; as long as at least two laser dots are visible on the subject, the distance between the device and the subject can be calculated. The Pi then uses the knowledge of how near or far the subject is to present a final image whose zoom level has been adjusted to match (and offset) the range of the subject from the camera, in effect canceling out the way an object appears larger or smaller based on distance.

We’ve seen visible laser dots as the basis of rangefinding before, but never tied into a zoom function. Doubtlessly, [ken conrad] will update his project with some example applications, but in the meantime we’re left wondering: is there a concrete, practical use case for this unusual device? We have no idea, but we’d certainly have fun trying to find one.

Sudo Google Assistant

A Raspberry Pi kicking around one’s workbench is a project waiting to happen — if they remain unused long enough to be considered a ‘spare.’ If you find you’ve been pining after an Alexa or your own personal J.A.R.V.I.S., [Novaspirit Tech] might be able to help you out — provided you have a USB mic and speaker handy — with an accessible tutorial for setting up Google Assistant on your Pi.

A quick run-through on enabling a fresh API client on Google’s cloud platform, [Novaspirit] jumps over to the Raspbian console to start updating Python and a few other dependencies. Note: this is being conducted in the latest version of Raspbian, so be sure to update before you get underway with all of your sudos.

Once [Novaspirit] gets that sorted, he sets up an environment to run Google Assistant on the Pi, authenticates the process, and gets it running after offering a couple troubleshooting tips. [Novaspirit] has plans to expand on this further in the near future with some home automation implementation, but this is a great jumping-off point if you’ve been looking for a way to break into some high-tech home deliciousness — or something more stripped-down — for yourself.  Check out the video version of the tutorial after the break if you like watching videos of guys typing away at the command line.

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Liquid Cooling Overclocked Raspberry Pi With Style

[HydroGraphix HeadQuarters] has earned his name with this one. While he is using mineral oil instead of hydro, he’s certainly done a nice job with the graphics of it. The ‘it’ in questions is an overclocked Raspberry Pi 3 in a transparent container filled with mineral oil, and with a circulating fan.

He’s had no problem running the Pi at 1.45 GHz while running a Nintendo 64 emulator, getting between 40 °C and 50 °C. The circulating fan is a five volt computer USB fan. It’s hard to tell if the oil is actually moving, but we’re pretty sure we see some doing so near the end of the video below the break.

Mineral oil is not electrically conductive, and is often used to prevent arcing between components on high voltage multiplier boards, but those components are always soldered together. If you’ve ever worked with mineral oil, you know that it creeps into every nook and cranny, making us wonder if it might work its way between some of the (non-soldered) contacts in the various USB connectors on this Raspberry Pi. Probably not, but those of us with experience with it can attest to it’s insidiousness.

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Keep the Burglars Away With Some Pi

Ten years ago, we never imagined we would be able to ward off burglars with Pi. However, that is exactly what [Nick] is doing with his Raspberry Pi home security system.

We like how, instead of using a standard siren, [Nick] utilized his existing stereo system to play a custom audio file that he created. (Oh the possibilities!) How many off the shelf alarm systems can you do that with?

The Pi is the brains of the operation, running an open source software program called Home Assistant. If any of the Z-Wave sensors in his house are triggered while the alarm system is armed, the system begins taking several actions. The stereo system is turned on via IR so that the digital alarm audio file can be played. Lights flash on and off. An IP camera takes several snapshots and emails them to [Nick].

Home Assistant didn’t actually have the ability to send images in an email inline at the time that [Nick] was putting together his system. What did [Nick] do about that? He wrote some code to give it that ability, and submitted it through GitHub. That new code was put into a later version of the program. Ah, the beauty of open source software.

Perhaps the most important part of this project is that there were steps taken to help keep the wife-approval factor of the system on the positive side. For example, he configured one of the scripts so that even if the alarm is tripped multiple times in succession, the alarm won’t play over itself repeatedly.

This isn’t [Nick’s] first time being featured here. Check out another project of his which involves a couple of Pi’s communicating with each other via lasers.

 

Conflict Escalates Between Brilliant Rat and 555 Timer

After [Casey Connor] captured and relocated a number of unwanted rodents in his home using commercially available live traps, he was presented with a problem: a rat had learned to avoid them.

In an epic, and adorable, conflict caught on video (and embedded below),  he documents the  designs used and how the rat escaped them by either recognizing the trap, or sheer agility. We can only tip our hat to the determination of both parties.

All the trap mechanisms are based on a 555 monostable solenoid triggering circuit that ensures that a pulse of sufficient duration is sent to the solenoid to trigger the trap correctly. This way even intermittent contacts will trigger the trap rather than just causing the solenoid to twitch without fully actuating. This is the same technique used to debounce a switch using a 555 timer.

A Raspberry Pi Zero detects motion using an IR camera to film the interesting parts. This is also a good indicator for when you’ve trapped your quarry – if you’re trying be humane then leaving it in a trap for days is counterproductive.

With the time and effort we spend building better and more complex rodent traps, we sometimes wonder who has cleverly trapped whom.

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Google AIY: Artificial Intelligence Yourself

When Amazon released the API to their voice service Alexa, they basically forced any serious players in this domain to bring their offerings out into the hacker/maker market as well. Now Google and Raspberry Pi have come together to bring us ‘Artificial Intelligence Yourself’ or AIY.

A free hardware kit made by Google was distributed with Issue 57 of the MagPi Magazine which is targeted at makers and hobbyists which you can see in the video after the break. The kit contains a Raspberry Pi Voice Hat, a microphone board, a speaker and a number of small bits to mount the kit on a Raspberry Pi 3. Putting all of it together and following the instruction on the official site gets you a Google Voice Interaction Kit with a bunch of IOs just screaming to be put to good use.

The source code for the python app can be downloaded from GitHub and consists of a loop that awaits a trigger. This trigger can be a press of a button or a clap near the microphones. When a trigger is detected, the recorder function takes over sending the stream to the Google Cloud. Speech-to-Text conversion happens there and the result is returned via a Text-To-Speech engine that helps the system talk back. The repository suggests that the official Voice Kit SD Image (893 MB download) is based on Raspbian so don’t go reflashing a memory card right away, you should be able to add this to an existing install.

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