Hacklet 47 – Thermal Imaging Projects

Thermal imaging is the science of converting the heat signature of objects to an image visible to humans. Everything above absolute 0 gives off some heat, and thermal imagers allow us to see that – even if there is no visible light in the room. Historically, thermal imaging systems have been large and expensive. Early systems required liquid nitrogen cooling for their bolometer sensors. Recent electronic advances have brought the price of a thermal image system from the stratosphere into the sub $300 range – right about where makers and hackers can jump in. That’s exactly what’s happened with the Flir Lepton module and the Seek Thermal camera. This week’s Hacklet is all about thermal imaging projects on Hackaday.io!

We start with [Pure Engineering] and Flir Lepton Thermal Camera Breakout. Flir’s Lepton thermal camera created quite a stir last year when it debuted in the Flir One thermal iPhone camera. The Lepton module used in the Flir One is a great standalone unit. Interfacing only requires an I2C interface for setup and an SPI interface for image data transfer. Actually using the Lepton is a bit more of a challenge, mainly because of its packaging. [Pure Engineering] made a simple breakout board which makes using the Lepton easy. It’s also breadboard compatible – which is a huge plus in the early phases of any project.

 

grideyeNext up is [AKA] with GRID-EYE BLE-capable thermal camera. This project is a Bluetooth low energy (BLE) thermal camera using Panasonic’s Grid-EYE 64 pixel thermal sensor. 64 pixels may not sound like much, but an 8×8 grid is enough data to see quite a bit of temperature variation. If you don’t believe it, check the project page for a video of [AKA] using Grid-EYE’s on-board OLED display. Grid-EYE was a Hackaday Prize 2014 semifinalist, and we featured a bio on [AKA] last year. The only hard part with building your own Grid-EYE is getting the sensor itself. Panasonic doesn’t sell them to just anyone, so you might have to jump through a few hoops to get your own.

 

pylepton[Kurt Kiefer] brought the FLIR Lepton to the Raspberry Pi with pylepton video overlay. This project uses the Lepton to overlay thermal data with images captured by the Raspbery Pi camera module. The Lepton interfaces through the I2C and SPI ports on the Pi’s GPIO pins. The results are some ghostly images of black and white thermal views over color camera images – perfect for your next ghost hunting expedition!  The entire project is implemented in Python, so it’s easy to import and use pylepton in your own projects. [Kurt] even gives an example of capturing an image with just 5 lines of code. Nice work, [Kurt]!

 

 

wificamFinally we have [Erik Beall] with WiFi Thermal Camera. [Eric] is using an 82×62 diode array to create thermal images. Unlike microbolometer sensors, diode/thermopile sensors don’t need constant calibration. They also are sturdier than Microelectricomechanical System (MEMS) based devices. This particular project users an array from Heimann Sensor. As the name implies, the sensor is paired with a WiFi radio, which makes using it to capture and display data easy. [Erik] must be doing something right, as WiFi Thermal Camera just finished a very successful Kickstarter, raising $143,126 on a $40,000 initial goal.

Are you inspired? A thermal imager can be used to detect heat loss in buildings, or heat generated by electrical faults – which means it would be a great project for the 2015 Hackaday Prize! If you want to see more thermal imaging projects, check out the thermal imaging projects list!

That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Hacking A Floating RGB LED Decorative Ball

Knowing that I’m always happy to get something new and glowy, my wife brought home a cheap “floating pool light” that she found on sale for roughly $10. This is a large white floating ball that has LEDs inside and cycles through different colors. Meant to be put into a pool for neat effects, we found it to be much more interesting just used around the house.

However, it was a bit too bright and cycled colors too quickly for our taste. It was actually somewhat distracting when we were just trying to sit and have a few beers late at night on our patio. This gave me a perfect excuse to tear it apart and start hacking… like I wasn’t going to do that anyway.

What I found inside was extremely simple. There’s a single un-marked chip that holds the different display modes (there were 3 display modes: warm, cool, and white). The LEDs were arranged in an array of Reds, Blues, Greens, and Whites (half marked yellow).

Continue reading “Hacking A Floating RGB LED Decorative Ball”

Blu-ray Laser Plotter Writes On Glow-in-the-dark Screen

This laser display is persistent thanks to a glow-in-the-dark screen. [Daniel] built it using a Blu-ray laser diode. As the laser dot traverses the screen, it charges the phosphors in the glow material, which stay charged long enough to show a full image.

The laser head is simple enough, two servo motors allow for X and Y axis control. A Micro Maestro 6-channel USB servo controller from Pololu drives the motors, and switches the diode on and off. This board offers .NET control, which [Daniel] uses to feed the graphics data to the unit. Check out the video demonstration below the fold to see a few different images being plotted. It’s shot using a night-vision camera so that you can really see where the laser dot is on the display. It takes time to charge the glow material so speeding up the plotting process could actually reduce the persistent image quality.

This is yet another project that makes you use those geometry and trigonometry skills.

Continue reading “Blu-ray Laser Plotter Writes On Glow-in-the-dark Screen”

1W Blue Laser – Remarkably Easy And Dangerous

[youtube=http://www.youtube.com/watch?v=lE3F7vjYx4U]

We’ve been covering Laser Hacks pretty much since the beginning but it’s surprising to see the niche market that has sprouted up around building powerful handheld modules. [Styropyro] filmed the video above as a tutorial on building a 1W blue laser. The “flashlight” that he starts with includes a heat sink intended for a laser diode. It seems there’s a lot of choices when choosing one of these build kits. A one Watt blue laser diode is press fit into the heat sink and wired in place. The body of the device receives a boost converter to get the batteries up to 1A, and once the assembly is complete the burning begins. It lights candles, matches, and pops balloons; the normal laser demo goodies.

So it’s a pretty easy build. But it’s also easy for someone being careless to damage their eyes. As [Styropyro] mentions in his comments, just looking at the dot created by the laser will damage your sight.

Laser Raygun Boasts 300mW, Hunts Klingons

laser-ray-gun

Phasers come with two settings: stun and kill. [Luke] took this seriously when he put two Blu-ray lasers into a toy raygun. He picked up the toy from Amazon for about twenty bucks and set to work.

The laser diodes are both pulled out of a 6x BD-R burner, which we think is a pretty expensive source to scavenge from. [Luke] removed the toy circuitry, reusing the trigger, top switch, and battery pack. The two diodes are mounted on a swiveling carriage which is turned 180 degrees to switch between the two diodes. A boost driver converts the 3v from the batteries up to 7v for the diodes.

This is a skillful conversion and [Luke] should be proud. Don’t miss the video after the break and if you’re thirsty for more take a look at the last hand held laser we featured.

Continue reading “Laser Raygun Boasts 300mW, Hunts Klingons”

Blu-Ray Laser Keychain

blu-ray-laser

[Jay] hacked a Blu-Ray laser diode into a keychain enclosure. He found a heavy brass keychain light from Lowe’s and stuffed the diode and a larger battery inside. The existing batteries weren’t powerful enough, so he drilled out the endcap to fit a 200mAh 3.6v lithium battery inside. He also modded the power button to only momentarily turn on the diode. With the larger battery, the laser can run for about an hour between charges. In addition to a Blu-Ray lasers, he also has versions with a 200mW red diode.

Related: Laser projector zippo

a–d, Crystal structures of the 1CzTrz-F (a,b) and 3CzTrz-F (c,d) compounds, determined by XRD. a,c, Diagrams of the two dimers of both crystallographic unit cells to show the molecular packing. b,d, Spatial arrangement of the acceptor–donor contacts in the 3D crystal structure. The triazine acceptor and the carbazole donor units are coloured orange and blue, respectively. The green features in d indicate co-crystallized chloroform molecules. (Credit: Oskar Sachnik et al., 2023)

Eliminating Charge-Carrier Trapping In Organic Semiconductors

For organic semiconductors like the very common organic light-emitting diode (OLED), the issue of degradation due to contaminants that act as charge traps is a major problem. During the development of OLEDs, this was very pronounced in the difference between the different colors and the bandgap which they operated in. Due to blue OLEDs especially being sensitive to these charge traps, it still is the OLED type that degrades the quickest as contaminants like oxygen affect it the strongest. Recent research published in Nature Materials from researchers at the Max Planck Institute for Polymer Research by Oskar Sachnik and colleagues (press release) may however have found a way to shield the electron-carrying parts of organic semiconductors from such contaminants.

Current density (J)–voltage (V) characteristics of electron- and hole-only devices of 3CzTrz and TPBi. (Credit: Oskar Sachnik et al., 2023)
Current density (J)–voltage (V) characteristics of electron- and hole-only devices of 3CzTrz and TPBi. (Credit: Oskar Sachnik et al., 2023)

In current organic semiconductors TPBi is used for electron transport, whereas for this research triazine  (Trz, as electron acceptor) and carbozole (Cz, as donor) were used and compared with the properties of leading-edge TPBi. While a few other formulations in the study did not show remarkable results, one compound (3CzTrz) was found using X-ray diffraction (XRD) to have a structure as shown on the right in the heading image, with the carbozole (in blue) forming essentially channels along which electrons can move, while shielded from contaminants by the triazine.

Using this research it might be possible to create organic semiconductors in the future which are free of charge-traps, and both efficiency and longevity of this type of semiconductor (including OLEDs and perovskites) can be improved immensely.