Tag Archives: sensors

Monitoring and visualising dual temperature and humidity sensor

via Arduino Blog


We recently featured Plotly and discovered how easy it is to analyse and beautifully visualize  data using their platform and API.

Now they shared with us a simple instructable to show to Arduino Community a hands-on experiment with ambient sensors:

The purpose of this instructable is to demonstrate how to hook up an Arduino + Ethernet Shield  and send data to Plot.ly’s Servers and create beautiful graphs. We will be using a dual temperature+humidity sensor (DHT22), and sending the results directly to Plotly.

Follow these easy steps, here’s what you’ll need:


And this is an example of the output:



Feeder Tweeter

via Raspberry Pi

This is hands down the best bird feeder project we’ve seen yet. I got an email from the folks at Manifold, a creative design agency in San Francisco, this week. One of their developers works from Denver, Colorado, and has been spending some time building the ultimate bird table. It’s autonomous, it’s solar-powered, it feeds, it photographs, it tweets images when a bird comes to feed, and it’s open source.

A PIR (passive infra-red) sensor detects when a bird lands at the table to feed, and triggers the camera. Photographs are then uploaded to Twitter. PIR’s a great choice here because it only responds to warm-body heat; if a leaf blows in front of the assembly, nothing will trigger, but if a toasty-warm little bird stops by for some seed, the sensor will detect it, and set off the camera.

This was not a trivial build. Issues like waterproofing, power constraints, and all those fiddly annoyances you find with outdoor projects had to be dealt with. The prototype (built from the ground up out of bits of wood: no pre-made bird feeders for these guys) took around 25 hours to put together. Here’s a time-lapse video of what happened in the workshop.

The first iteration of the Tweeter Feeder had a few bugs: the webcam in the assembly didn’t offer high enough resolution for decent pictures of the birds, and was swapped out with a Raspberry Pi camera board. But the camera board’s focal depth wasn’t right for this project, so an additional lens was put into the assembly – and then all the camera code had to be changed to reflect the switch. With cracking results: here’s a before and after picture.

The PIR sensor was getting false positives from changes in temperature due to the sun on the feeder: an additional motion sensor was added to iron those out. A light sensor found its way into the assembly to stop the camera triggering when there wasn’t enough ambient light for a reasonable photograph. The solar panel positioning wasn’t optimal. And so on and so on – but the bugs have all been stomped now, and the end result is a thing of beauty.

Read Chad’s account of what they were up to on Manifold’s blog (which has a ton of information on the development of the Feeder Tweeter), and then head to the Feeder Tweeter site itself, where there is an area for developers with a hardware list, wiring diagrams, links to all the code you’ll need on GitHub and much more. And let us know if you decide to make or adapt the Feeder Tweeter for your own use – we’d like to see what you come up with!




AirPi – the next step

via Raspberry Pi

Liz: When Clive and I are asked what schools project in the past year has really knocked our socks off, our response is usually the AirPi, an inexpensive pollution and weather monitor developed by Alyssa Dayan and Tom Hartley, a pair of sixth formers from Westminster School in London. AirPi won the PA Consulting Raspberry Pi competition earlier this year, where entries had to “make the world a better place”, and we regularly use it in talks as an example of the amazing things that can be achieved with a Pi and some ingenuity.

Tom, Alyssa and Air Pi

AirPi is an open-source weather and pollution monitoring system, with the ability to record and stream data. Including the Pi, it comes in at £55: tens of times cheaper than equivalent off-the-shelf equipment. Things have come a long way since the first, competition-winning iteration of AirPi: Alyssa and Tom have been learning about PCB design and entrepreneurship  and have just launched a Tindie to raise funds to sell the kit. I’ve asked them to write about what they’ve been doing, and what progress they’ve made with AirPi over the last few months. Here’s what Tom had to say: 

For the last 10 months, I’ve been working with Alyssa Dayan to create the AirPi. Its a shield for the Raspberry Pi capable of recording data about the air quality and current weather conditions, coupled with code to upload its recordings to the internet in real time. Just last week, we started a fundraiser for our kit on Tindie!

AirPi in its current incarnation. Note shiny PCB.

The project started back in October 2012, when one of our teachers (we’re both sixth form students) told us about the PA Consulting Raspberry Pi competition. The challenge was to create something, using a Pi, which would “make the world a better place”. We didn’t have a very clear idea of what to design, so we looked at the different kinds of hardware we could connect to the Pi. After checking Adafruit’s website, we discovered a vast assortment of sensors, many of which measured meteorological information. Over the next 4 months, we purchased and added on various parts from all over the world (testing and calibrating as we went along), starting with the DHT22 which measured temperature and humidity, and finishing with the UVI-01 which measures UV levels. That was the very first incarnation of the AirPi.

Simultaneous to developing the hardware, we started developing the software. It was split up into Python scripts (which are currently undergoing a complete rewrite!) running on the Pi, and a live updating website (with HTML5 websockets!). By February, we’d started putting basic instructions on how to make your own AirPi onto our website (this was a stipulation of the competition), and one of the most incredible moments we had was when an awesome guy from the UK, Paul, emailed us and said he’d already put one together. Before that point we had no idea that people would actually be interested in building an AirPi themselves!

Early version of AirPi on breadboard

In March, we were invited to the finals of the competition. After polishing up our website and tidying our breadboard (above), we headed to PA Consulting’s offices near Royston. We started by getting a tour around, and seeing the awesome workshop and labs that PA had. In the afternoon we were judged the winners in our category. After the event was over, the project gained some interest online, and about 10 other people have put an AirPi together by hand since then. Of special note however, was Taylor Jones, an electronics engineer in the US, who emailed us saying he wanted to design a PCB for the AirPi. I have now started learning that dark art, but at the time neither I nor Alyssa had any experience making PCBs so we were incredibly glad to have his help!

Final AirPi kit

After three iterations, we had a functional PCB – this made the AirPi much more compact and easy to assemble, so we decided to start making kits for it. We signed up for a stand the Elephant & Castle Mini Maker Faire - this was brilliant as it gave us a fixed date we had to get the kits ready by. After reinvesting the prize money from the PA consulting competition into components, PCBs, packaging and stickers, we were ready to head off to the Maker Faire with the kits. We sold out of all 15 kits we had purchased for the day! In the weeks after the Faire, we were contacted by several very awesome groups of people: a new green initiative in Ho Chi Minh city in Vietnam has purchased three kits in order to measure the air quality there, and the Chaos Computer Club in Germany has bought 15 in order to teach children to solder. We’ve even had several archivists in the UK who’ve asked us to give them some so they can accurately monitor the temperature and humidity of the books they’re looking after! In the near future, we’re hoping to develop a 3D printed case for the AirPi which will allow people to put it outside a lot easier.

AirPi hooked up to a Pi

After many requests for a kit, we’ve started a fundraiser on Tindie (sort of like a Kickstarter, but especially for electronics). If you’re interested in ordering a kit to measure temperature, humidity, UV, NO2, CO, light and air pressure for £55, then you can go to this page - we’ll be shipping them out in late September. Alternatively, we have published all the source code, instructions, components needed and even the PCB files and schematics online, so if you want make and assemble one yourself (or improve upon our design), feel free to do so. We love open source – without the amazing work of so many people online, there could be no AirPi. If you build one, we’d love to hear from you and add it to our website. Thank you for reading!

PiPlanter: a plant growth monitor

via Raspberry Pi

We’ve see a lot of clever irrigation devices for gardeners being made with the Pi, but PiPlanter is the most complete (and the best documented) system we’ve seen so far. It does far more than simple irrigation. PiPlanter monitors temperature, ambient light, ambient humidity and soil humidity; it outputs that data to a MySQL database, controls a pump to water the plants depending on that data, and outputs the data as graphs and text. (It also tweets that text and uploads the graphs to Flickr hourly so that Devon, the PiPlanter’s owner, can keep an eye on things.)

Devon has documented the build minutely, with circuit diagrams, a ton of code, and several videos. Here, he explains more about the sensor array he built.

You can read much more at Devon’s blog, and replicate the project yourself. Thanks Devon: more power to your green thumb!

DIY Air Quality Sensing from HabitatMap and Sonoma Tech

via Arduino Blog


High-precision air quality monitors are normally very expensive, but Tim Dye of Sonoma Technology is on a mission to change that.  He’s been working with Michael Heimbinder and habitatmap.org to create a low-cost sensor system that when designed properly and integrated into a software platforms can provide valid data.

AirCasting is a platform for recording, mapping, and sharing health and environmental data using Arduino and Android. It combines an Arduino with a set of sensors for air quality measurement; temperature, humidity, and carbon monoxide, nitrogen dioxide, and particulate matter. The system combines the sensors using an Arduino Uno and then sends the data to an Android app using Bluetooth. The plans are all open for modification, so you can add your own sensors as needed. A heart rate monitor and an LED vest can also be linked to the AirCasting app, providing a complete the system for realtime, wearable feedback of your body’s reaction to the environmental air quality.

There are many DIY air quality measurement projects online, but most of them are not calibrated against known standards or professional equipment. But Dye and his colleagues have tested the AirCasting particulate matter sensors against the same equipment Sonoma Technology uses for precise measurement, and they’ve gotten surprisingly good results. Correctly constructed and deployed, the AirCasting shows promise as a low-cost alternative to complement the expensive high-end air monitors.

AirCasting is a collaboration between many groups:  Michael Heimbinder of habitatmap.org manages the project, and Tim Dye of Sonoma Technology consults on design, data evaluation, and field deployment; Dr. Iem Heng and Raymond Yap of the City Tech Mechatronics Technology Center designed and built the hardware; Dr. Andy Zhang designed and built the monitor casings; Valentine Leung designed and built the LED garments, and Brooke Singer has helped guided the project with a mind towards interactivity and public engagement.

The data from your AirCasting air monitor can be uploaded to the AirCasting database, which aggregates data from all AirCasting contributors, or can be sent to your own database and all the code for the project is open source and available through GitHub

The website AirCasting.org provides links to all the software and hardware plans.

Recantha’s only gone and made a tricorder.

via Raspberry Pi

I’ve been waiting for…ooh, just over a year, for someone to do this. Recantha, an old hand here in the comments and on the forums, has built a tricorder.

There surely can’t be anyone here without a passing familiarity with Star Trek, but just in case: the tricorder is a made-up thing used by the crew of the Enterprise to measure stuff, store data and scout ahead remotely when exploring strange new worlds, seeking out new life and new civilisations, and all that jazz. Despite its made-up-ness, the tricorder remains a terribly desirable thing. I’ve always wanted to be able to tell whether my planet is M-class or not.

Recantha has bodged together his home-made tricorder using a Pi, some sensors (two for temperature, and one each for magnetism and distance), an LCD display, some switches, a light-resistant resistor, a thermistor and an Arduino Leonardo clone. We hope he keeps adding sensors to it, and maybe, later on, a camera board, until he runs out of space. How about a Geiger counter (this one already works with the Pi)?

Here’s a spot of video explaining what everything on the Picorder does:

(Best of all, the whole thing is cased in LEGO.)

And here’s some more video, showing the thing in action.

If you’re interested in reproducing or building on this project, Recantha’s blogged about it (he has an excellent website, all about Raspberry Pi), and has left a guide to the project over at Pideas, the new site for collecting Raspberry Pi projects. (Go and add something of your own!) Thanks very much for this, Recantha; our office costume parties will now have a dash of added realism. Jamesh has drawn the short straw and will be dressed as Nog.

Wearable soundscape from Canada

via Arduino Blog

BioCircuit by Dana Ramler


I’m reblogging from Core77 this interesting wearable project because I’d like to highlight the using of Arduino Lilypad board:

Bio Circuit stems from our concern for ethical design and the creation of media-based interactions that reveal human interdependence with the environment. With each beat of the heart, Bio Circuit connects the wearer with the inner workings of their body.

It was created at Emily Carr University by Industrial Design student Dana Ramler, and MAA student Holly Schmidt and provides a form of bio feedback using data from the wearer’s heart rate to determine what “sounds” they hear through the speaker embedded in the collar of the garment. Here’s the schematic of technology:

BioCircuit - Technology



Have a look at the video below to see how it works and don’t miss BioCircuit Project page on Dana’s Portfolio:



Wireless Sensor Network for Temperature Sensing

via Arduino Blog

This is an interesting implementation of Arduino and Wireless comunication. The user [priyansmurarka] posted:

Ok, so here is the basic problem statement. I need to develop a temperature sensing system such that the temperature from the sensor node is relayed to a co-ordinator sensor and then the co-ordinator node shows the user in a simple graphical form.

For the wireless communication, I used Xbee Series 2 modules with Arduino Board Shields.

Uses Melexis Temperature sensor and Arduino Board to monitor and plot ambient temperature.

The realization of this project is well documented on the [blog], with code, graphs and pictures.


via Arduino Blog

How about a new way to make music? [cpeckmusic] has it’s way to do it, with is project Sharpy.

Sharpy is an electronic instrument that was designed and built by composer Charles Peck. The instrument utilizes three infrared distance sensors to control the sound, which is produced digitally with an Arduino board and GinSing shield. So as users interact with these sensors, there is a clear auditory connection to their physical actions.

Despite having only three sensors, the instrument is capable of a variety of sounds. This is because Sharpy has three possible operating states, each of which assigns a different set of parameters to the three sensors. State 1 is initiated by covering the sensor on the user’s left first. The instrument will then stay in State 1 until no sensors are being covered. Therefore, the user must completely remove their hands form the instrument in order to change states. Concordantly, State 2 is initiated using the middle sensor and State 3 using the sensor on the right. The short improvisation in this video demonstrates a few of these sonic possibilities.

I suggest you to watch the [video] of the live performance. If you’re interested in more works check his official [website]

[#arduinotour] Matera Report, Prossima Puntata: Reggio Emilia

via Arduino Blog

Ecco un piccolo video report della puntata dell’Arduinotour a Matera (c’é anche un set su Flickr). Questa edizione del tour é stata caratterizzata dalla partecipazione di un ragazzo francese (partito dalla Bretagna e volato per un week-end a Matera – Grande Baptiste!) che ha condiviso con noi la sua esprienza di sviluppatore di open energy monitor, un framework open source per la visualizzazione di consumi online, di cui parleremo presto in una intervista ad hoc. (il blog di Arduino ha trattato precedentemente questa storia, vai al post).

Causa maltempo il workshop é stato ospitato presso le Monacelle, un bed & breakfast poco l’ontano dall’Incubatore, all’interno dei Sassi. Un grazie a Sviluppo Basilicata per il supporto e l’aiuto nell’organizzazione dell’evento.

Per chi si stesse chiedendo quando e dove si farà il prossimo workshop #arduinotour, eccovi serviti: Reggio Emilia a fine gennaio (26-27), presso il neonato Fablab ospitato all’interno dello Spazio Gerra.

Se volete portare l’#arduinotour a casa vostra riempite questo form. Se volete spargere il verbo fate il like sulla pagina dell’arduinotour su facebook.

Wednesday grab bag

via Raspberry Pi

Christmas presents

Apparently, it’s the most wonderful time of the year. We have been thinking about what to get for the Raspberry Pi owner in your life. Happily, MakeZine have done the hard work for us, and have come up with a terrific gift guide. Head over and check it out – once, of course, you’ve stopped by our own store and bought your Raspberry Pi fan a branded t-shirt, lovingly hand-knitted from Santa’s beard hair by elves*. All profits on the shirts go to support the charitable work of the Raspberry Pi Foundation.

*Details about t-shirt production may or may not be strictly speaking true.

Baby monitor

Here’s something I’ve been hoping one of you would produce for a while now. If you’ve got kids, you’ll know that many baby monitors are disgustingly expensive bits of kit, whose price remains as high as it is in a pretty unpleasant bit of exploitation of the fear and worry that every new parent experiences. So I was really pleased to see Matt Kaar, a Pi owner from Virginia, make his own networked, high-fidelity monitor from a Pi and a USB microphone. He’s very pleased with the results: “You can hear a pin drop.” You can follow Matt’s detailed instructions on his website if you’d like to make your own. (Thanks very much for responding to my request to write about it, Matt!)

These are all the parts you’ll need to make your own. Matt says the whole setup was “easier than I’d thought” – this is a project that even beginners will be able to approach.

I’m sure that once the $25 camera board is released in the new year we’ll start to see some cheap camera monitors being hacked too.

Plan 9

We’re very pleased to see that Plan 9 has been ported to the Pi. Plan 9 is an open-source Unix-type operating system, which was originally developed at Bell Labs as a research OS. What’s particularly interesting about Plan 9 is that everything behaves like a file, whether it’s a local or a network resource. We recommend you have a play with it!

Glenda, the Plan 9 bunny

You can download an image for your SD card, alongside documentation and a pdf newbie’s guide.

Raspberry Pipboy

More than a year ago, people on our forums started talking about using the Raspberry Pi in a very specific piece of cosplay. If you’ve played Fallout, you’ll know that no self-respecting apocalypse survivor goes anywhere without her Pipboy. People were wondering whether a Raspberry Pi could be used to drive a working piece of costume, perhaps with a GPS, and definitely with a small screen and lots of blinkenlights.

I thought that particular thread of conversation had died quietly: I was wrong. Ryan Grieve  has made a really nice example using a car reversing panel, a tub of polymer pellets, a handful of leds and an Adafruit cobbler.

His Pipboy has functionality including a world map, local map, radio and a twitter client – or at least it did before some shonky home-wiring caused the whole arrangement to burst into flames. Happily, the Pi survived, and photos were taken before the disaster. Ryan also has code so you can put your own together – just please be more careful with the wiring if you make one yourself. Electricity’s not a toy, kids.

Good luck in fixing her back together, Ryan! We congratulate you on your flameproofness.


Here’s a project with a more practical application. Gasser is a Pi-based, networked, mobile pollutant sensor for detecting nitrogen dioxide, ozone and sulphur dioxide, developed in Paris.

Gasser v2 prototype

This self-contained unit’s BOM cost comes in at €255 (the majority of that cost is taken up by the very accurate sensor); this is cheaper and smaller than equivalent devices – and it’s still only a prototype! We wish LaboCitoyen all success with the project; it’s great to see a Pi being used to make our cities healthier places.


Like Raspberry Pi? Like 3D printing? Like biscuits? (OK, Americans: cookies.) This Thingiverse cookie cutter pattern from Tesla’s Moustache also comes with a recipe to make your own dough.

Learn about relays

Alex from RasPi.tv has some video to show you how to use relays to turn what he calls “useful, real, BIG things” like fans and lamps on and off, according to environmental conditions – too hot and the fan will turn on, too dark and the lamp will turn on. You can also hook the devices up to the network, so you can use a connected device, like your phone, to turn them on and off; and just because he can, Alex has also added some sound effects. This is a great tutorial. If you’re interested in learning about physical computing, it’s well worth watching this video and reading Alex’s blog post. RasPi.tv has plenty of other fun tutorials – I recommend you spend a few minutes browsing through the collection!


Finally, here’s a project to use up some of the LEGO you’ve been asking for for Christmas. Tom Rees has instructions on building a remote-controlled LEGO car, steered with an Xbox controller.