[NightHawkInLight] has been playing around with the diamagnetic properties of bismuth. Diamagnetic materials get a lot of attention due to their strange ability to produce the opposite of the magnetic field going through them. In simpler terms, metals like iron are attracted to magnets; metals like bismuth repel them.
[NightHawkInLight] built his own interpretation of a common lab example used to demonstrate this remarkable property, a levitator. A levitator is made by sandwiching a magnet between two plates of diamagnetic material. One of the plates is given a magnetic field opposite of the magnet underneath it by a stronger magnet placed some distance away. When this is done, the magnet in between wants to repel away from the plate above, only to find that as it gets closer to the plate below it is equally repelled, creating a stable system.
Eventually the magnet above will need realignment, but [NightHawkInLight] assures us this is only once every 100 years. Video after the break. Continue reading “Bismuth Crystals Hold Magnet Suspended For 100 Years”
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!
Versaloon is an open source, USB connected project, that centers around an STM32 processor and provides a standard JTAG pinout. Above you see the Nano version which has a 10-pin JTAG connector, but there is also a 20-pin option on the Handy model. Great, another JTAG programmer. Well this can do a bit more than that. With a bit of help from the software it has been turned into a programmer for ten different types of hardware. Obviously this should be able to program anything that works with the JTAG protocol, but the script adapts it to work as an In System (or In Circuit) Programmer too. So far the list of programming targets includes STM32, LPC1000, LPC900, STM8, AR8, MSP430, and a few others.
We had some trouble finding an actual picture of this hardware. If you’ve got one, snap a picture and leave a link to it in the comments along with your thoughts on the device.