Breadboarding RAM

If you’ve ever wanted to dive in and take a look at how memory hardware is implemented here is a good example of how to implement some latching circuits with ether BJT or CMOS transistors. BJTs require biasing resistors which increases the complexity and power consumption when compared to CMOS. If power consumption isn’t an issue you could certainly make some really fast logic.

Most modern on chip RAM is made using SRAM because it only takes six transistors to implement(vs eight) and is pretty fast. When it comes to density DRAM can get one bit of storage by using a single transistor and capacitor(putting the capacitor underneath he transistor can save even more space). All that said, latches and flip flops are still a very useful (and common) tool when working with digital circuits.

Japanese Micro Planes

Some very well engineered micro planes(translated) have been buzzing around the net. The goal here is ultra light weight. These suped-up paper planes have a remarkable target weight of around 10 grams (translated). The lighter the micro plane is the slower and more maneuverable it will be leading to some pretty interesting and scary applications. For controls it looks like many of the planes are using infrared receivers/transmitters (much like you would find in a TV remote hint hint). Getting the lightest plane possible has forced the designers to come up with some pretty ingenious tricks. For example, instead of using packaged servos they use a coil of wire wrapped around a rare earth magnet to control the flaps. You can see these home made “servos” in action after the break.

Some have taken a more classic approach and used rubber band power instead of a li-po/motor combo.

[via Make]

[Read more...]

Permanent Root exploit found for g2

The g2 has finally been rooted. Even though a temporary root exploit was found shortly after the phones release, a NAND lock prevented modifying the non-volatile RAM for a permanent root. Some controversy surrounded the g2 when it was erroneously thought to have a rootkit protecting the OS.  Supposedly the rootkit would watch for changes to the file system and then reset the phone to default settings when any unauthorized changes were made.  On the other hand a NAND lock functions by fooling the operating system into thinking there isn’t any memory available, essentially “locking” the memory in key areas.  Once it was discovered to have the NAND lock it was only a matter of time before the g2 was permanently rooted.  NAND locks have become a popular (and unsuccessful) deterrent employed by device makers to stop the jailbreaking comunity.  While this exploit is nothing groundbreaking it is another notch in the belt for the jailbreaking community and a welcome benefit to g2 users.

ROS turns three

Turtles!

Since its first debut three years ago, ROS has been gaining some popularity with the robotics folks.  It’s behind the scenes of those impressive quadcopters you may remember from a while back.  ROS helps abstract the lower level functions of a robot by supplying lots of code for commonly used components (wiimote for example). Being an “operating system”  it comes with lots of nice features you would expect, like a package manager.  It’s open source and many of their projects are well documented making it easy get started.

Check out the video after the break to see it in action [Read more...]

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