There’s a good chance that you use a MEMS accelerometer every single day. It’s the small chip that let your smart phone automatically adjust its screen orientation. They’re great chips, and since they’re mass-produced you can add them to your projects for a song (if you can abide the tiny packaging). But we have no idea of how they are made and only a inkling of how they work. [Bill Hammack] has filled that knowledge gap with this explanation of how MEMS accelerometers are made and how they function.
Our base knowledge comes from the acronym: Micro Electro-Mechanical Systems. There’s something in the chip that moves (so much for solid state electronics; and it makes us wonder if these wear out). [Bill] includes a diagram in his video after the break which shows the silicon-based system that moves as it is affected by gravity. This changes the capacitive properties of the structure, which can be measured and reported to a microcontroller for further use. The structure is built using an intricate etching process which we never want to try out at home.
Looking for a project in which to use one of these devices? We’ve always been fond of this POV device.
Continue reading “The Engineer Guy explains how MEMS accelerometer chips work”
Unfortunately [manekinen] wrecked a couple of AVRs during his tinkering. Not letting this get him down he decided to blow them up to see what would happen. In exchange for their precious magic smoke the AVRs revealed a good portion of their silicon die.
While the details are a little sparse it seems like he hooked them up to a high (and possibly reverse) source to blow open the chips casing. From the pictures it looks like he was able to reveal some of the flash or SRAM (the big multi colored rectangles) and what could possibly be the power supply. Be sure to checkout the videos after the break for some silicon carnage.
Continue reading “Exploding an AVR”
[Jeri Ellsworth] made this silicon inverter at home, by hand. It took her two years to get the process figured out and achieve something we didn’t think was possible. The complexity of manufacture, and the wide range of tools and materials needed seem insurmountable but she did it anyway. Her home chip fab Flickr set is well commented and details her work area and part of the processing. If you’re hurting for more check out her 40 minute Metalab talk which we’ve embedded after the break.
If her name sounds familiar but you just can’t place it you may know her from The Fatman and Circuit Girl. We’ve also featured some of her hacks, such as her Pinball challenge against [Ben Heckendorn], and her giant Etch-a-Sketch.
Continue reading “Jeri makes integrated circuits”
Ever wanted to make your own LED? You might be tempted to after reading how easy it is. No, this won’t really be a practical LED that you would use to light a project, but it is very cool anyway. [Michael] picked up a box of Moissanite, or Silicon Carbide, on eBay for roughly $1. Making the LED is as easy as putting your positive lead to the crystal and touching it with a sewing needle attached to a negative lead. He has tips on how to get the best results as well as a little bit of history of LEDs on the site.
The silicon wizards at Flylogic have certainly posted an interesting chip this time around. The Intel 4004 was the first widely used microprocessor. The logic gates are much larger than you’d find in modern chips. The unique feature is that each gate is designed to make the most efficient use of the silicon instead of the standardized shapes you find now. They’ve uploaded a full image of the chip.
For an introduction to silicon hacking, we reccomend [bunnie]’s talk from Toorcon and [Karsten]’s talk from 24C3. You can find many more posts on the topic in our silicon tag.
Peripheral manufacturer Datel has been hard at work attempting to crack the PSP 3000 since its release. They’ve developed the Lite Blue Tool battery to force the PSP into service mode so hackers can run any arbitrary code they want. According to MaxConsole, Datel performed a silicon level investigation of the PSP’s chips to determine how to break into service mode. This means they decapsulated the the chips and reverse engineered any cryptographic protections. We’d love to hear exactly what chips were being used since some are fundamentally flawed.
Silicon hacking has always been a favorite topic of ours and we suggest you check out [Chris Tarnovsky]’s decapsulation technique to learn more about it.
[Karsten Nohl] has recently joined the team on Flylogic’s blog. You may remember him as part of the team that reverse engineered the crypto in MiFare RFID chips. In his first post, he starts out with the basics of identifying logic cells. By studying the specific layout of the transistors you can reproduce the actual logic functions of the chip. The end of post holds a challenge for next week (pictured above). It has 34 transistors, 3 inputs, 2 outputs, and time variant behavior. Also, check out the Silicon Zoo which catalogs individual logic cells for identification.