Monthly Archives: March 2017

Arduino-controlled 360° camera trap for animal photography

via Arduino Blog

Using an Arduino, wildlife observer and hiking hacker Andrew Quitmeyer modified a spherical camera to take pictures when motion is detected.

If you’d like to photograph wildlife without actually being there to scare the animals off (or because you would eventually get bored), a great solution is a camera trap. These devices can trigger a camera when animals move nearby, hopefully capturing interesting images. Generally, you need to point your camera in the right direction, but Quitmeyer got around this by using a 360 camera instead to eliminate this placement bias.

In order to control the device, he rigged up his own system with PIR motion sensors and an Arduino Uno to prompt the camera as well as power it on and off. The hack looks effective, though voiding an expensive camera’s warranty like this will certainly scare a few Makers off!

You can see more about how this project was pulled off on Instructables, and find the Arduino code used on GitHub.

The All-Seeing Pi: a Raspberry Pi photo booth

via Raspberry Pi

Have you ever fancied building a Raspberry Pi photo booth? How about one with Snapchat-esque overlay filters? What if it tweeted your images to its own Twitter account for all to see?

The All-Seeing Pi on Twitter

The All Seeing Pi has seen you visiting @Raspberry_Pi Party @missphilbin #PiParty

Introducing The All-Seeing Pi

“Well, the thing I really want to say (if you haven’t already) is that this whole thing was a team build”, explains one of the resource creators, Laura Sach. “I think it would be a brilliant project to do as a team!”

The All-Seeing Pi Raspberry Pi Photo Booth

The resource originally came to life at Pycon, where the team demonstrated the use of filters alongside the Camera Module in their hands-on workshops. From there, the project grew into The All-Seeing Pi, which premiered at the Bett stand earlier this year.

The All-Seeing Pi on Twitter

The All Seeing Pi has seen you, @theallseeingpi #PiatBETT #BETT2017

Build your own photo booth

To build your own, you’ll need:

  • A Camera Module
  • A monitor (we used a touchscreen for ours)
  • Two tactile buttons (you can replace these later with bigger buttons if you wish)
  • A breadboard
  • Some male-female jumper leads

If you’re feeling artistic, you can also use a box to build a body for your All-Seeing Pi.

By following the worksheets within the resource, you’ll learn how to set up the Camera Module, connect buttons and a display, control GPIO pins and the camera with Python code, and how to tweet a photo.

The All-Seeing Pi Raspberry Pi Photo Booth

Raspberry Pi Foundation’s free resources

We publish our resources under a Creative Commons license, allowing you to use them for free at home, in clubs, and in schools. The All-Seeing Pi resource has been written to cover elements from the Raspberry Pi Digital Curriculum. You can find more information on the curriculum here.

Raspberry Pi Digital Curriculum


The post The All-Seeing Pi: a Raspberry Pi photo booth appeared first on Raspberry Pi.

IoTuseday: WiFi Maximizer with DIY Yagi-Uda Antenna

via SparkFun Electronics Blog Posts

In a previous IoTuesday post, I gave examples of makeshift antennas you could build at home. I wanted to make my own and create a kind of “WiFi Divining Rod.” I used a SparkFun ESP8266 Thing Dev board and OLED attached to the antenna, which would connect to a WiFi access point and display the received signal strength indication (RSSI) on the OLED. I could then change the antenna’s position and orientation to determine the best connection to the access point.

DIY Yagi next to ESP8266 Thing Dev board

I liked the design of the Yagi-Uda antenna, as they are simple to build and seem to be fairly forgiving (mine didn’t turn out particularly straight). I followed Biotele’s Instructable to create an antenna out of Popsicle sticks, paper clips and glue.

The Instructable shows a 15-element Yagi-Uda, which theoretically gets you about a 15 dBi gain (see here to learn more about decibel reference values). I needed something that was smaller and handheld. One nice thing about Yagi-Uda antennas is that you can just trim elements off the end and trade gain/beamwidth for antenna length (more or less – it does change the beam pattern).

You can download the AB9IL Java app that Biotele used in their article to view the beam pattern of a Yagi-Uda. Here, I entered the same dimensions of Biotele’s antenna and then removed the last eight “director” elements. This, in theory, would get me less gain (around 10 dBi) with a slightly wider beamwidth.

Yagi-Uda Plot

After building the antenna, I attached a Thing Dev board (using some foam tape) and an OLED to the end of the antenna’s backbone, which kept the U.FL cable as close as possible to the antenna’s driven element. I wrote a quick Arduino sketch that simply reported the RSSI of the WiFi connection on the OLED.

RSSI on OLED from ESP8266

I performed some basic tests to see how the custom Yagi-Uda compared against the Thing Dev board’s PCB antenna, and I was pleasantly surprised. I went out to the front of the SparkFun building (by our beehive – about 75 meters away from the building) and held up an unmodified Thing Dev board. I changed its orientation to find the highest RSSI, and the best receive strength I could get was around -67 dBm.

RSSI readings

I tested the RSSI again with the “WiFi Maximizer” (best name I could come up with for a Thing Dev board taped to a makeshift Yagi-Uda antenna), and found that that I could get around -61 dBm (same position, not necessarily the same orientation).

Testing the Yagi-Uda outside

With my completely unscientific testing, I figured I was getting around 6 dB of gain over the onboard PCB antenna, which isn’t bad considering the backbone was crooked, the elements weren’t exactly lined up, and there was no impedance matching whatsoever (among a whole host of other issues, I’m sure).

I have not performed a line-of-sight distance test, but I’m willing to bet I would be able to connect to our building’s WiFi at a farther range than with just the PCB antenna. If you’re looking for a quick (and very cheap) way to boost your Internet of Things (IoT) device’s connection, then this makeshift antenna is one good way. This might work well, for instance, in a classroom setting where students need to build a device to take measurements at a location where the nearest WiFi access point is a kilometer away.

Additionally, the directional nature of the Yagi-Uda means that you could potentially use this setup in a small-scale transmitter hunting game (assuming the transmitter was broadcasting a 2.4 GHz WiFi signal).

What other antenna tricks can you offer to help boost the range of IoT devices (specifically, something in the 2.4 GHz or 5 GHz bands) without spending a fortune?

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Arch Your Eyebrow at Impression Products V. Lexmark International

via hardware – Hackaday

When it comes to recycled printer consumables, the world seems to divide sharply into those who think they’re great, and those who have had their printer or their work ruined by a badly filled cartridge containing cheaper photocopy toner, or God knows what black stuff masquerading as inkjet ink. It doesn’t matter though whether you’re a fan or a hater, a used printer cartridge is just a plastic shell with its printer-specific ancilliaries that you can do with what you want. It has performed its task the manufacturer sold it to you for and passed its point of usefulness, if you want to fill it up with aftermarket ink, well, it’s yours, so go ahead.

There is a case approaching the US Supreme Court though which promises to change all that, as well as to have ramifications well beyond the narrow world of printer cartridges. Impression Products, Inc. v. Lexmark International, Inc. pits the printer manufacturer against a small cartridge recycling company that refused to follow the rest of its industry and reach a settlement.

At issue is a clause in the shrink-wrap legal agreement small print that comes with a new Lexmark cartridge that ties a discounted price to an agreement to never offer the cartridge for resale or reuse. They have been using it for decades, and the licence is deemed to have been agreed to simply by opening the cartridge packaging. By pursuing the matter, Lexmark are trying to set a legal precedent allowing such licencing terms to accompany a physical products even when they pass out of the hands of the original purchaser who accepted the licence.

There is a whole slew of concerns to be addressed about shrink-wrap licence agreements, after all, how many Lexmark owners even realise that they’re agreeing to some legal small print when they open the box? But the concern for us lies in the consequences this case could have for the rest of the hardware world. If a precedent is set such that a piece of printer consumable hardware can have conditions still attached to it when it has passed through more than one owner, then the same could be applied to any piece of hardware. The prospect of everything you own routinely having restrictions on the right to repair or modify it raises its ugly head, further redefining “ownership” as  “They really own it”. Most of the projects we feature here at Hackaday for example would probably be prohibited were their creators to be subject to these restrictions.

We’ve covered a similar story recently, the latest twist in a long running saga over John Deere tractors. In that case though there is a written contract that the farmer buying the machine has to sign. What makes the Lexmark case so much more serious is that the contract is being applied without the purchaser being aware of its existence.

We can’t hold out much hope that the Supreme Court understand the ramifications of the case for our community, but there are other arguments within industry that might sway them against it. Let’s hope Impression Products v. Lexmark doesn’t become a case steeped in infamy.

Thanks to [Greg Kennedy] for the tip.

Lexmark sign by CCC2012 [CC0].

Filed under: Current Events, hardware, news

New 5V step-up/step-down voltage regulator S9V11F5

via Pololu Blog

Our newest step-up/step-down voltage regulator, the S9V11F5, takes input voltages between 2 V and 16 V and increases or decreases that voltage as necessary to produce a fixed 5 V output with a typical efficiency of over 90%. (Note that it requires a minimum of 3 V to start up, but it can operate down to 2 V once it is running.) It can temporarily deliver peaks of around 2 A, and the maximum continuous output current depends on the input voltage as shown in the graph below:

The ability to raise or lower the input voltage makes this regulator especially well suited for battery-powered applications where the nominal battery voltage is close 5 V, such as when using four NiMH cells, since the battery voltage transitions from above 5V to below as the battery discharges. The wide input voltage range is also great for applications where you want a lot of flexibility in power supply choice or for systems powered by alternative energy sources like solar or wind, where the output voltage can vary a lot.

With a wider input voltage range and its ability to deliver more current, the S9V11F5 is a higher-performance alternative to our popular S7V7F5 buck-boost regulator, all while being even smaller in size thanks to its double-sided assembly.

For more information on this regulator, visit the S9V11F5 product page, and for other regulator options, you can take a look at our full selection of step-up/step-down regulators, step-up voltage regulators, and step-down voltage regulators.

Raspberry Pi, A-Star 32U4, and Wild Thumper robot

via Pololu Blog

Forum user coyotlgw made this teleoperated Raspberry Pi robot. The robot is controlled remotely over SSH via the Raspberry Pi’s WiFi connection, and snapshots of the webcam feed are available via a Motion web server. The motors of the Dagu Wild Thumper 4WD chassis are driven by a Pololu Dual MC33926 Motor Driver for Raspberry Pi connected to a Raspberry Pi 2 Model B. A Pololu A-Star 32U4 Mini LV interfaces with and records readings from temperature, pressure, humidity, and UV/IR/visible light sensors.

It wasn’t available when they built the robot, but coyotlgw points out the A-Star 32U4 robot controller with Raspberry Pi bridge is an option to consider for similar builds. This robot connects the Raspberry Pi and A-Star Mini with USB; the robot controller would make I²C communication easier. You would still need external motor drivers, because the robot controller’s MAX14870 is not appropriate for the Wild Thumper motors.

For more pictures, details, and a discussion of the issues encountered during the build, see the forum post.