Do Space Probes Fail Because Of Space Weather?

September 11, 2018 by Brian Benchoff 40 Comments

Over the past few decades, numerous space probes sent to the far-flung reaches of the Solar System have fallen silent. These failures weren’t due to communications problems, probes flying into scientifically implausible anomalies, or little green men snatching up the robotic scouts we’ve sent out into the Solar System. No, these space probes have failed simply because engineers on Earth can’t point them. If you lose attitude control, you lose the ability to point a transmitter at Earth. If you’re managing a space telescope, losing the ability to point a spacecraft turns a valuable piece of scientific equipment into a worthless, spinning pile of junk.

The reasons for these failures is difficult to pin down, but now a few people have an idea. Failures of the Kepler, Dawn, Hayabusa, and FUSE space probes were due to failures of the reaction wheels in the spacecraft. These failures, in turn, were caused by space weather. Specifically, coronal mass ejections from the Sun. How did this research come about, and what does it mean for future missions to deep space?

Continue reading “Do Space Probes Fail Because Of Space Weather?” →

How Big Is Your Oscilloscope? One Inch?

September 11, 2018 by Al Williams 30 Comments

We are anxious to see the finished product of [Mark Omo’s] entry into our one square inch project. It is a 20 megasample per second oscilloscope that fits the form factor and includes a tiny OLED screen. We will confess that we started thinking if you could use these as replacements for panel meters or find some other excuse for it to exist. We finally realized, though, that it might not be very practical but it is undeniably cool.

There are some mockup PCB layouts, but the design appears feasible. A PIC32MZ provides the horsepower. [Mark] plans to use an interleaved mode in the chip’s converters to get 20 megasamples per second and a bandwidth of 10 MHz. It appears he’ll use DMA to drive the OLED. In addition to the OLED and the PIC, there’s a termination network and a variable gain stage and that’s about it.

Continue reading “How Big Is Your Oscilloscope? One Inch?” →

Automagic Tool Makes KiCAD Schematic Symbols From PDFs

September 11, 2018 by Kerry Scharfglass 28 Comments

Last time we talked about a KiCAD tool it was to describe a way to make the zen-like task of manual assembly more convenient. But what about that most onerous of EE CAD tasks, part creation? Home makers probably don’t have access to expensive part library subscriptions or teams of people to create parts for them, so they are left to the tedium of creating them by hand. What if the dream tool existed that could read the darn PDF by itself and make a part? It turns out [Sébastien] made that tool and it’s called uConfig.

uConfig has a pretty simple premise. It scrapes manufacturer datasheets in PDF form, finds what it thinks are diagrams of parts with pin names, functions, etc, and emits the result as parts in a KiCAD library. To aid in the final conversion [Sébastien] added rules engine which consume his custom KiCAD Style Sheets which specify how to categorize pins. In the simple case the engine can string match or use regex to let you specify things like “all pins named VDD[A-C] should be power pins”. But it can also be used to move everything it thinks belongs to “GPIOB” and stick them on the bottom of the created symbol. We could imagine features like that would be of particular use breaking out gigantic parts like a 400 ball BeagleBone on a chip.

Thanks for the tip [arturo182]!