Member Since: January 28, 2006

Country: United States




  • This looks pretty nice. Are you considering carrying the version with the lens-aligned IMU for SLAM or structure-from-motion kinds of applications?

  • Those are called spade lugs, or spade connectors, or things like that. They're used a lot on cars and household appliances for example.

  • That's not actually the issue date— it's the "not valid before" date. (A lot of browsers describe it as an issue date, since it's usually set to the day the cert was issued, but the browsers are wrong: gory technical details here.) It's 100% reasonable, for example, to get a new cert today that isn't valid until next week when I plan to install it, or something like that. Certificates don't actually contain an indication of when they were issued. They definitely don't contain an indication of when their underlying keypair was generated, which is what we really want to know.

    With all the heartbleed-related revocations it's become clear that different CAs do things differently when replacing a compromised key's cert. Comodo and DigiCert seem to produce new certs which have the same validity period as the old cert; Thawte produces new certs which are only valid from the time of reissue but have the same end-date as the old cert. (Thawte's behavior seems more correct to me, but I'm sure the folks at DigiCert have a reason for doing it the way they do.)

    To actually know whether a vulnerable organization has responded safely, you'd probably have to find their old certificate via something like the SSL Observatory, and then verify that the old cert has been revoked and replaced by a cert using a different keypair.

  • It can take a while for a gps receiver to get a fix after a cold start. It has to find several satellites, possibly by an exhaustive search of code shifts/doppler shifts, and it has to be able to listen to one for long enough to receive orbital status updates (up to 36 seconds for the ephemeris and 12.5 minutes for the almanac!).

    Warm and hot starts are faster because the module can remember some of this information from the last time. Cellphone GPS fixes can also be faster by retrieving almanac/ephemeris updates and coarse location hints over the internet (this is "assisted GPS", or AGPS).

  • The marine animal tracking projects I know of offhand don't try to track the animal precisely when they're underwater: they wait for the fin they're attached to to break the surface (or they detach after a set time and float to the surface) and acquire a GPS fix then.

  • Ouch, another SparkFun impulse buy coming up...

  • You are correct of course but we do need a good name for the really common "async serial using TTL voltage levels" interface. I see people use "RS-TTL" for it sometimes. "TTL-level serial" is maybe less slang-y and still gets the point across.

  • I thought the Slanket was first, then knocked off (and marketed to the point of ridicule) as the Snuggie? (Not that it alters your basic point. Especially since it sounds like something called "Freedom Blanket" predated them both by a small margin. I guess sleeved blankets were just in the zeitgeist then.)

  • A DAC driven by a µc is still a DDS, even if the NCO is in software… it just can't run as fast as a hardware DDS like the AD958.

  • You beat me to it! I figure SCOPRION is one of the products of SprakFun.

No public wish lists :(