Extreme Pi Overclocking With Mineral Oil

Liquid cooling is a popular way to get a bit of extra performance out of your computer. Usually this is done in desktops, where a special heat sink with copper tubing is glued to the CPU, and the copper tubes are plumbed to a radiator. If you want dive deeper into the world of liquid cooling, you can alternatively submerge your entire computer in a bath of mineral oil like [Timm] has done.

The computer in question here is a Raspberry Pi, and it’s being housed in a purpose-built laser cut acrylic case full of mineral oil. As a SoC, it’s easier to submerge the entire computer than it is to get a tiny liquid-cooled heat sink for the processor. While we’ve seen other builds like this before, [Timm] has taken a different approach to accessing the GPIO, USB, and other connectors through the oil bath. The ports are desoldered from the board and a purpose-built header is soldered on. From there, the wires can be routed out of the liquid and sealed off.

One other detail used here that  we haven’t seen in builds like this before was the practice of “rounding” the flat ribbon cable typically used for GPIO. Back in the days of IDE cables, it was common to cut the individual wires apart and re-bundle them into a cylindrical shape. Now that SATA is more popular this practice has been largely forgotten, but in this build [Timm] uses it to improve the mineral oil circulation and make the build easier to manage.

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A Hacked Solution For Non-Standard Audio Modules

When life hands you lemons, lemonade ends up being your drink of choice. When life hands you non-standard components, however, you’ve got little choice but to create your own standard to use them. Drinking lemonade in such a situation is left to your discretion.

The little audio record and playback modules [Fran Blanche] scored from eBay for a buck a piece are a good example. These widgets are chip-on-board devices that probably came from some toy manufacturer and can record and playback 20 seconds of audio with just a little external circuitry. [Fran] wants to record different clips on a bunch of these, and pictured using the card-edge connector provided to plug them the recording circuit. But the pad spacing didn’t fit any connector she could find, so she came up with her own. The module and a standard 0.1″ (2.54 mm) pitch header are both glued into a 3D-printed case, and the board is connected to the header by bonding wires. It makes a nice module that’s easily plugged in for recording, and as [Fran] points out, it’s pretty adorable to boot. Check it out in the video below.

Sure, the same thing could have been accomplished with a custom PCB breaking out the module’s pins to a standard card-edge connector. But [Fran] knows a thing or two about ordering PCBs, and our guess is she wanted to get this done with what was on hand rather than wait for weeks. There’s something to be said for semi-instant gratification, after all. And lemonade.

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Hiding Executable Javascript in Images That Pass Validation

Here’s an interesting proof-of-concept that could be useful or hazardous depending on the situation in which you encounter it. [jklmnn] drew inspiration from the work of [Ange Albertini] who has documented a way to hide Javascript within the header of a .gif file. Not only does it carry the complete code but both image and the Javascript are seen as valid.

With just a little bit of work [jklmnn] boiled down the concept to the most basic parts so that it is easy to understand. Next, a quick program was written to automate the embedding of the Javascript. Grab the source code if you want to give it a try yourself.

Let’s get back to how this might be useful rather than harmful. What if you are working on a computer that doesn’t allow the browser to load Javascript. You may be able to embed something useful, kind of like the hack that allowed movies to be played by abusing Microsoft Excel.

A Small Replacement for Large Programming Headers

No matter how small you make your embedded projects, you still need a way to program the MCU. Standard programming headers can be annoyingly large for those very small projects. [Danny] wrote in to tell us how we can save room on our PCB designs using special spring loaded connectors, rather than large headers.

There are so many small embedded development systems, such as the Trinket that still rely on standard headers. Reducing the size of the programming headers and interface headers is an issue that deserves more attention than it currently receives. Based on Tag-Connect, a proprietary connector built around pogo-style pins, your PCB does not actually require any on-board mating connector. The PCB footprint simply has test-pads that connect with the pogo-pins and holes that allow for a rock solid connection. While the Tag-Connect header is a bit expensive (it costs about $34), you only need to buy it once.

It would be great to see even smaller Tag-Connect cables. Do you have a similar solution? What about something even smaller and more compact? Write in to tell us about any ultra-compact connector solutions you have been using!

The Straddler makes AVR breadboarding truly plug and play

the_straddler_avr_programmer

It’s not that breadboarding AVR circuits is difficult. But you have to admit that it takes some time to set everything up. We don’t label the top of our DIP chips so that you know what each pin does just by looking. Which means that wiring up the programmer involves pulling out the datasheet. [Vinnie] found the solution to this problem which is to make one of these interface PCBs for each AVR chip family. The long pins make it easy to drop over the top of your microcontroller, which is where the name comes from.

His first stab at the idea was just a hunk of home etched PCB which broke out the programming pins into the 6-pin ICSP standard. This second rendition uses the 10-pin standard and adds a few extras into the mix. He included decoupling capacitors which need to be used in every circuit anyway. There’s a crystal along with its load capacitors. This clock source is a snap to enable by burning some fuses. If you choose to use the internal oscillator instead this hardware won’t interfere. The LED is used to get you up and running with blinky firmware as quickly as possible. He plans to add jumper in the next revision which can disconnect this components from the I/O pin. Now you just need to add a 10-pin header to that USB keyboard AVR programmer and you’re in business.

Bread Head makes AVR programming a snap

bread_head_quick_avr_programming_header

[Quinn] over at Blondihacks has been working with AVR microcontrollers a lot recently, and wanted a quick way to program the ATtiny13a (her current AVR of choice) while the chip is still seated in a breadboard.

To speed up code revision and testing, she built a small programming header that she calls the Bread Head. The device is wonderfully simplistic, consisting of little more than snappable header pins and a bit of upside-down protoboard.

She soldered six headers to the top (formerly the bottom) side of the board, while a set of eight oversized headers were soldered to the opposite side of the programmer. Small bits of wire were soldered in to connect all of the appropriate pins together before [Quinn] slipped the header snugly over the top of the ATtiny and gave it a quick test. Everything worked perfectly, so she slathered in in epoxy for sturdiness and called it a day.

She says that the programmer works so well that she’s likely to make a similar header for other common AVRs too.

Print your own header shrouds

Don’t get us wrong, printable whistles are cool and all, but these printable header shrouds make us think that filament printers like the Makerbot and RepRap might just be worth their salt. This utilitarian purpose is a departure from the souvenirs, toys, and art that we’re used to seeing from the expensive development toys tools.

The six and ten pin header shrouds are designed for a snug fit that makes it easy to glue them onto the plastic spacers of male pin headers. We use IDC plugs and ribbon cable all the time in our projects, but never seem to order shrouded connectors; this is perfect for us. It makes us wonder what other PCB-friendly printable designs we’ve been missing out on? Surely someone’s been printing stand-offs with threaded inserts, right? If you know of something useful that we can share with the rest of the readers, don’t hesitate to send in a tip.

[via Dangerous Prototypes]