This Raspberry Pi Is A Stereo Camera And So Much More

December 30, 2018 by Jenny List 27 Comments

Over the years we have featured a huge array of projects featuring the Raspberry Pi, but among them there is something that has been missing in all but a few examples. The Raspberry P Compute Module is the essentials of a Pi on a form factor close to that of a SODIMM module, and it is intended as a way to embed a Pi inside a commercial product. It’s refreshing then to see [Eugene]’s StereoPi project, a PCB that accepts a Compute Module and provides interfaces for two Raspberry Pi cameras.

What makes this board a bit special is that as well as the two camera connectors at the required spacing for stereophotography it also brings out all the interfaces you’d expect on a regular Pi, so there is the familiar 40-pin expansion header as well as USB and Ethernet ports. It has a few extras such as a pin-based power connector, and an on-off switch.

Where are they going with this one? So far we’ve seen demonstrations of the rig used to create depth maps with ROS (Robot Operating System). But even more fun is seeing the 3rd-person-view rig shown in the video below. You strap on a backpack that holds the stereo camera above your head, then watch yourself through VR goggles. Essentially you become the video game. We’ve seen this demonstrated before and now it looks like it will be easy to give it a try yourself as StereoPi has announced they’re preparing to crowdfund.

So aside from the stereophotography why is this special? The answer comes in that it is as close as possible to a fresh interpretation of a Raspberry Pi board without being from the Pi Foundation themselves. The Pi processors are not available to third party manufacturers, so aside from the Odroid W (which was made in very limited numbers) we have never seen a significant alternative take on a compatible Raspberry Pi. The idea that this could be achieved through the Compute Module is one that we hope might be taken up by other designers, potentially opening a fresh avenue in the Raspberry Pi story.

The Raspberry Pi Compute Module has passed through two iterations since its launch in 2014, but probably due to the lower cost of a retail Raspberry Pi we haven’t seen it in many projects save for a few game consoles. If the advent of boards like this means we see more of it, that can be no bad thing.

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HD Video And Telemetry Link Uses Standard WiFi Hardware

December 27, 2018 by Donald Papp 3 Comments

[GlytchTech] decided to implement his own Digital Data Link (DDL) for his drone experiments, and by using a Raspberry Pi Zero and some open-source software, he succeeded in creating a mostly self-contained system that delivers HD video and telemetry using an Android phone as a display.

USB tethered Android phone used as a display and touch interface.

The link uses standard WiFi hardware in a slightly unusual way to create a digital data link that acts more like an analog system, with a preference for delivering low latency video and a graceful drop-off when signal quality gets poor. A Raspberry Pi Zero, Alfa NEH WiFi card, external antenna, battery, and a 3D printed enclosure result in a self-contained unit. Two are needed: one for each end of the link. One unit goes on the drone and interfaces to the flight controller, and the other is for the ground station.

A companion android app allows for just about any old Android phone to serve as video feed, on-screen display of telemetry data, and touchscreen interface.

The software is DroneBridge (GitHub repository) and it implements Wifibroadcast which uses WiFi radios, but without the usual WiFi functionality. A Raspberry Pi is the usual platform, but there’s also an ESP32 port. The software is capable of even more, but so far suits [GlytchTech]’s needs just fine, and he was able to refine his original Watch_Dogs-inspired hacking drone with it.

Machine Learning On Tiny Platforms Like Raspberry Pi And Arduino

December 25, 2018 by Bryan Cockfield 25 Comments

Machine learning is starting to come online in all kinds of arenas lately, and the trend is likely to continue for the forseeable future. What was once only available for operators of supercomputers has found use among anyone with a reasonably powerful desktop computer. The downsizing isn’t stopping there, though, as Microsoft is pushing development of machine learning for embedded systems now.

The Embedded Learning Library (ELL) is a set of tools for allowing Arduinos, Raspberry Pis, and the like to take advantage of machine learning algorithms despite their small size and reduced capability. Microsoft intended this library to be useful for anyone, and has examples available for things like computer vision, audio keyword recognition, and a small handful of other implementations. The library should be expandable to any application where machine learning would be beneficial for a small embedded system, though, so it’s not limited to these example applications.

There is one small speed bump to running a machine learning algorithm on your Raspberry Pi, though. The high processor load tends to cause small SoCs to overheat. But adding a heatsink and fan is something we’ve certainly seen before. Don’t let your lack of a supercomputer keep you from exploring machine learning if you see a benefit to it, and if you need more power than just one Raspberry Pi you can always build a cluster to get your task done just a little bit faster, too.

Thanks to [Baldpower] for the tip!

Arduino And Pi Share Boardspace

December 24, 2018 by Brian McEvoy 18 Comments

A Raspberry Pi Zero (W) and Arduino are very different animals, the prior has processing power and connectivity while the latter has some analog to digital converters (ADCs) and nearly real-time reactions. You can connect them to one another with a USB cable and for many projects that will happily wed the two. Beyond that, we can interface this odd couple entirely through serial, SPI, I2C, and logic-level signaling. How? Through a device by [cburgess] that is being called an Arduino shield that supports a Pi0 (W). Maybe it is a cape which interfaces with Arduino. The distinction may be moot since each board has a familiar footprint and both of them are found here.

Depending on how they are set up and programmed, one can take control over the other, or they could happily do their own thing and just exchange a little information. This board is like a marriage counselor between a Raspberry Pi and an Arduino. It provides the level-shifting so they don’t blow each other up and libraries so they can speak nicely to one another. If you want to dig a bit deeper into this one, design files and code examples are on available.

Perhaps we’ll report on this board at the heart of a pinball machine retrofit, a vintage vending machine restoration, or maybe a working prop replica from the retro bar in Back to the Future II.

LEDs And Pi Let You Virtually Decorate This Online Christmas Tree

December 23, 2018 by Dan Maloney 6 Comments

Anyone who has decorated a Christmas tree knows that the lights are what really make the look. But no matter how many strings you wrap around it, there never seems to be enough. Plus the standard sets either sit there and do nothing, or just blink on and off at regular intervals. Yawn.

But hackers aim higher, and [leo.currie]’s interactive “paintable” Christmas tree takes the lighting game a step beyond. The standard light strings are replaced with strings of WS2811 RGB LEDs which are wired to an ESP8266. A camera connected to a Raspberry Pi is setup up to stream images of the tree to all and sundry on the Interwebz, but with a special twist: it also creates a map of every light on the tree. That allows the lights to be controlled individually in response to user inputs on a web page hosted on the Pi. The upshot is that you can paint the tree with any color you like in real time, or upload various animated GIFs to display on the tree. You can play with the tree directly, or watch a replay on the video below when that Pi inevitably gets hugged to death.

Imagine the possibilities with this. Why not hang a lot of LED strings vertically from the eaves of your house and make a huge, low-resolution display? We’ve featured plenty of large, interactive LED Christmas displays before, and we’d love to see what you come up with.

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A Star-Trek-Inspired Robot With Raspberry Pi And AI

December 21, 2018 by Al Williams 1 Comment

When [314Reactor] got a robot car kit, he knew he wanted to add some extra things to it. At about the same time he was watching a Star Trek episode that featured exocomps — robots that worked in dangerous areas. He decided to use those fictional devices to inspire his modifications to the car kit. Granted, the fictional robots were intelligent and had a replicator. So you know he won’t make an actual working replica. But then again, the ones on the TV show didn’t have all that either.

A Raspberry Pi runs Tensorflow using the standard camera. This lets it identify objects of interest (assuming it gets them right) and sends the image back to the operator along with some identifying information. The kit already had an Arduino onboard and the new robot talks to it via a serial port. You can see a video about the project, below.

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Neural Network Knows When Cat Wants To Go Outside

December 21, 2018 by Lewin Day 38 Comments

Neural networks are computer systems that are vaguely inspired by the construction of animal brains, and much like human brains, can be trained to obey the whims of the almighty domestic cat. [EdjeElectronics] has built just such a system, and his cat is better off for it.

The build uses a Raspberry Pi, fitted with the Pi Camera board, to image the area around the back door of the house. A Python script regularly captures images and passes them to a TensorFlow neural network for object recognition. The TensorFlow network returns object type and positions to the Python script. This information can be used to determine if there is a cat in the frame, and if it is inside or outside. If the cat remains in position for ten consecutive frames, a text message is sent via Twilio, indicating to the owner to let the cat in or out, as the case may be.

Thirty years ago, object classification was a pie-in-the-sky technology, but now you can run it on a $30 computer to figure out where your pets are. What a time we live in! A similar solution to this problem may be a cat door that unlocks via facial recognition. Video after the break.

[Thanks to Baldpower for the tip!]

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