When you buy a mass-market mobile phone, you’re making the decision to trust a long list of companies with your private data. While it’s difficult for any one consumer to fully audit even a single piece of consumer technology, there have been efforts to solve this problem to a degree. The Pinephone is one such example, with a focus on openness and allowing users to have full control over the hardware. [Martijn Braam] is a proud owner of such a device, and took advantage of this attitude to add a thermal imager to the handset.
The build is not a difficult one, thanks to the expansion-friendly nature of the Pinephone hardware. The rear of the phone sports six pogo pins carrying an I2C bus as well as power. [Martin] started by modifying the back cover of the phone with contacts to interface with the pogo pins. With this done, the MLX90640 thermal imager was attached to the case with double-sided tape and wired up to the interface.
Panasonic’s Grid-EYE sensor is essentially a low-cost 8×8 thermal imager with a 60 degree field of view, and a nice breakout board makes it much easier to integrate into projects. [Pure Engineering] has created an updated version of their handy breakout board for the Grid-EYE and are currently accepting orders. The new breakout board is well under an inch square and called the GridEye2 (not to be confused with the name of the main component, the AMG8833 Grid-EYE by Panasonic.)
A common way to interface with the Grid-EYE is over I2C, but to make connecting and developing on a PC more straightforward, [Pure Engineering] has made sure the new unit can plug right into their (optional) CH341A development board to provide a USB interface. Getting up and running on a Linux box is then as simple as installing the Linux drivers for the CH341A, and using sample C code to start reading thermal data from an attached GridEye2 board.
It is said that you’re not a sysadmin if you haven’t warmed up a sandwich on server. OK, it’s not widely said; we made it up, and only said it once, coincidentally enough after heating up a sandwich on a server. But we stand by the central thesis: never let a good source of excess thermal energy go to waste.
[Joseph Marlin] is in the same camp, but it’s not lunch that he’s warming up. Instead, he’s using the heat generated by his Folding@Home rig to sprout seeds for beautiful tropical flowers. A native of South Africa Strelitzia reginae, better known as the striking blue and orange Bird of Paradise flower, prefers a temperature of at least 80° F (27° C) for the two months its seeds take to sprout. With all the extra CPU cycles on a spare laptop churning out warm air, [Joseph] rigged an incubator of sorts from a cardboard box. A 3D-printed scoop snaps over the fan output on the laptop and funnels warm air into the grow chamber. This keeps the interior temperature about 15 degrees above ambient, which should be good enough for the seeds to sprout. He says that elaborations for future versions could include an Arduino and a servo-controlled shutter to regulate the temperature, which seems like a good idea.
The Bird of Paradise is a spectacular flower, but if growing beautiful things isn’t your style, such a rig could easily sprout tomatoes or peppers or get onions off to a good start. No matter what you grow, you’ll need to basics of spinning up a Folding@Home rig, which is something we can help with, of course.
In the world of computer security, the good news is that a lot of vendors are finally taking security seriously now, with the result that direct attacks are harder to pull off. The bad news is that in a lot of cases, they’re still leaving the side-door wide open. Side-channel attacks come in all sorts of flavors, but they all have something in common: they leak information about the state of a system through an unexpected vector. From monitoring the sounds that the keyboard makes as you type to watching the minute vibrations of a potato chip bag in response to a nearby conversation, side-channel attacks take advantage of these leaks to exfiltrate information.
Side-channel exploits can be the bread and butter of black hat hackers, but understanding them can be useful to those of us who are more interested in protecting systems, or perhaps to inform our reverse engineering efforts. Samy Kamkar knows quite a bit more than a thing or two about side-channel attacks, so much so that he gave a great talk at the 2019 Hackaday Superconference on just that topic. He’ll be dropping by the Hack Chat to “extend and enhance” that talk, and to answer your questions about side-channel exploits, and discuss the reverse engineering potential they offer. Join us and learn more about this fascinating world, where the complexity of systems leads to unintended consequences that could come back to bite you, or perhaps even help you.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
When the first thermal cyclers for the polymerase chain reaction came out in the 1980s, they were as expensive as a market driven by grant money could make them. Things haven’t got much better over the years, largely shutting STEM classes and biohackers out of the PCR market. That may be about to change, though, if the €99.00 PocketPCR thermal cycler takes hold.
PCR amplifies DNA in a three-step process: denaturation, which melts double-stranded DNA into single strands; annealing, which lets small pieces of primer DNA bind to either side of the region of interest; and elongation, where the enzyme DNA polymerase zips along the single strands starting at the primer to replicate the DNA. The cycle repeats and copies of the original DNA accumulate exponentially. Like any thermal cycler, [Urs Gaudenz]’s PocketPCR automates those temperature shifts, using a combination of PCB-mounted heating elements and a cooling fan. The coils rapidly heat a reaction block up to the 99°C denaturation temperature, the fan brings that down to the 68°C needed for annealing, and then the temperature ramps back up to 72°C for elongation with thermostable DNA polymerase. PID loops keep the reaction temperature precisely controlled. The whole thing is, as the name suggests, small enough to fit in a pocket, and can either be purchased in kit form or scratch-built from the build files on GitHub.
We applaud [Urs]’ efforts to get the power of PCR into the hands of citizen scientists. Quick and dirty thermal cyclers are one thing, but Pocket PCR has a great fit and finish that makes it more accessible.
One can quibble that perhaps there are other ways to go about preventing your MOSFETs from burning, including changes to the electrical design. But he decided to take a page from [Kerry Wong]’s design book and go big. [Kerry]’s electronic load was air-cooled and capable of sinking 100 amps; [tbladykas] only needed 60 or 70 amps or so. Since he had an all-in-one liquid CPU cooler on hand, it was only natural to use that for cooling.
The IXYS linear MOSFET dangles off the end of the controller PCB, where the TO-247 device is soldered directly to the copper cold plate of the AiO cooler. This might seem sketchy as the solder could melt if things got out of hand, but then again drilling and tapping the cold plate could lead to leakage of the thermal coupling fluid. It hasn’t had any rigorous testing yet – his guesstimate is 300 Watts dissipation at this point – but as his primary endpoint was to stop the MOSFET fires, the exact details aren’t that important.
We’ve seen a fair number of liquid-cooled Raspberry Pis and Arduinos before, but we can’t find an example of a liquid-cooled electronic load. Perhaps [tbladykas] is onto something with this design.
[DZL] used an MLX90640 sensor to create a DIY thermal imager with a small OLED display, but since the sensor is relatively low-resolution at 32×24, displaying the data directly looks awfully blocky. Gaussian interpolation to improve the display looks really good, but it turns out that the full Gaussian interpolation isn’t a trivial calculation write on your own. Since [DZL] wanted to implement it on a microcontroller, the lightweight implementation was born. The project page walks through the details of Gaussian interpolation and how some effective shortcuts were made, so be sure to give it a look.