Amanda Ghassaei (previously featured on Arduino Blog with Glitchbox and Vocal Effect box ) published the instructions to build an Arduino-powered infrared touchscreen / coffee-table interface that she’s been using to control various music and graphics applications on her computer.
Although the project was done a while ago, she considers it special because it was her first Arduino/electronics project and recently she’s taken it apart to refinish the wood and fix a few things and then published detailed documentation on Instructables:
The touchscreen uses infrared (IR) sensing to detect fingers and other objects on the screen. An IR laser at each corner shines IR light across the surface of the screen. When a finger or other object touches the surface, it causes the IR light to scatter in many directions. Some of this light is directed down into the screen, towards an array of 64 IR sensors. By scanning through the sensors, you can determine the x and y position of the touch event(s) and use this to control a variety of apps.
I’ve got a sample of Pi NoIR, the camera board variant with no infrared filter that we talked about here yesterday, on my desk. I thought you’d like to see a picture. You’ll notice one big difference from the regular camera board: the solder mask is black, not green, so you can easily tell which is which if you own both.
Click to embiggen!
In other news, Eben has just got back from a one-day visit to San Francisco, where he was presenting at GigaOM. Here’s his talk to see you into the weekend: enjoy!
You may have heard rumours about something we’re calling Pi NoIR (Pi, noinfrared) – it’s been a very badly kept secret. Some months ago we featured some work that was being done at Reading Hackspace, where members were removing the infrared filter to use the camera to sense infrared signals, and for low-light work, especially with wildlife. The Reading camera boards ended up going to the Horniman Museum in London, where they’re currently being used to track the activity of corals at night.
A lot of you are interested in wildlife monitoring and photography. London Zoo mentioned to us that the infrared filter on the standard Pi camera board is a barrier to using it in projects like the Kenyan rhino-tracking project they’re running based around the Pi – although the Pi is used as the base of the project and does all the computational tasks required, they started out having to use a more expensive and more power-hungry camera than the Pi camera board, because that IR filter meant that it wasn’t useable at night.
Once the news from Reading Hackspace and the Horniman got out, we were inundated by emails from you, along with comments here on the blog and on the forums, asking for a camera variant with no IR filter. You wanted it for camera effects, for instances where you wanted to be able to see IR beams from remote controls and the like, for low-light photography illuminated by IR, and especially for wildlife photography. Archeologists wanted to take aerial photographs of fields with an IR camera to better see traces of lost buildings and settlements. Some botanists got in touch too: apparently some health problems in trees can be detected early with an IR camera.
Initially we thought it wasn’t going to be something we could do: Sunny, who make the sensor, filter and lens package that’s at the heart of our camera board, did not offer a package without the filter at all. Removing it would mean an extra production line would have to be set up just for us – and they had other worries when we started to talk to them about adding an infrared camera option. They told us they were particularly concerned that users would try to use a camera board without a filter for regular daytime photography, and be would be upset at the image quality. (There’s a reason that camera products usually integrate an infrared filter – the world looks a little odd to our eyes with an extra colour added to the visible spectrum.)
We convinced them that you Pi users are a pragmatic and sensible lot, and would not try to replace a regular camera board with a Pi NoIR – the Pi NoIR is a piece of equipment for special circumstances. So Sunny set up an extra line just for us, to produce the Pi NoIR as a special variant. We will be launching Real Soon Now – modules are on their way and we’re aiming for early November – so keep an eye out here for news about release.
RS Components have got their hands on an early prototype, and Andrew Back produced a blog post about using it in timelapse wildlife photography at night, with infrared illumination. You can read it at DesignSpark, RS’s community hub.
Andrew’s garden is a paradise of slugs.
Jon and JamesH would like you to be aware that the red flashes are most likely due to not letting the camera “warm up” sufficiently before taking each picture. Jon says: “Raspistill defaults to 5 second previews before capture which should be enough. If using the “-t” parameter then don’t set it below 2000. The “-tl” parameter is for timelapse, which doesn’t shut the camera down between picture grabs.” (We’re checking the white balance before release all the same, though.)
Let us know if you’re in the market for a Pi NoIR in the comments. We’d love to hear your plans for one! We’re planning to sell it for $25, the same price as a regular camera module. Check back here: we’ll tell you as soon as it’s released.
There’s a question we’ve been asked very frequently about the camera board. A number of you want to use it for night-time photography, and ask if we can remove the IR filter. Notably, London Zoo are planning to deploy the camera board and Pi in a number of camera traps in Africa, where they’ll be looking for nocturnal animals and for poachers. The problem is, we source the sensor/lens package as a sealed unit from Sunny, so we don’t have the option to remove the infra-red (IR) filter, which is sandwiched inside that unit. This causes trouble for those of you who want to take low-light pictures of wildlife, or for security or astronomy.
Over at Reading Hackspace, Gary Fletcher (also attached to London Zoo, and planning to use a Pi camera in his role at the Horniman Museum aquarium for detecting the night time spawning of corals, which he hopes to deploy in Guam in just over a month’s time) mailed us to ask about the filter. Eben didn’t hold out much hope for manual removal of the filter, but suggested that some very careful scalpel work might achieve results. If you attempt this, be aware that it’s not really a supported option, and that if you try you may break your camera board. (Gary, Barnaby and team did break the first board they attempted this with.) Also, be careful around IR sources if you’re playing with IR photography – the human eye doesn’t have a look-away or blink reflex associated with IR, and you can damage your eyes if you stare at a very bright IR light.
We think the results are worth it, though. Here’s some instruction and illustration from Reading Hackspace, with special thanks to Barnaby Shearer. First of all, here’s a howto video.
This video demonstrates IR pickup: you can watch the tip of a soldering iron change colour as it heats up.
Another demonstration, this time of night vision. The scene is illuminated with the IR from a television remote control.
Finally, here’s a demonstration of the pattern of light from a Kinect, filmed with the filter-less camera board.
The usual warnings apply, but if you do decide to try this yourself, we’d love to see the results. A huge thanks to Gary, Barnaby, and all at Reading Hackspace for being prepared to imperil a camera board, and for all the helpful video!
Edit to add: Gary has just left a comment below with more tips and instructions. Check it out if you’re planning to try this at home.
If you want to check your house for hot air leaks, take pictures of the heat coming off a rack of equipment, or just chase the most dangerous animal, [Arnie], through the jungles of central america, a thermal imaging camera is your friend. These devices normally cost a few thousand dollars, but the team behind the Mu Thermal Camera managed to get the price down to about $300.
The basic idea behind the Mu Thermal Camera is overlaying the output of an infrared thermopile – basically, an infrared camera – on top of the video feed of a smart phone’s camera. This is an approach we’ve seen before and something that has even been turned into a successful Kickstarter. These previous incarnations suffered from terrible resolution, though; just 16×4 pixels for the infrared camera. The Mu thermal camera, on the other hand, has 160×120 pixels of resolution. That’s the same resolution as this $2500 Fluke IR camera. After the indiegogo campaign is over, the Mu camera will eventually sell for $325.
We have no idea how the folks behind the Mu camera were able to create a thermal imaging with such exceptional resolution at this price point. The good news is the team will be open sourcing the Mu camera after their indiegogo run is over. W’e'd love to see those docs now, if only to figure out how a thousand dollars of infrared sensor is crammed into a $300 device.