• More data on PCB Gremlins

    12/23/2017 at 17:47 0 comments

    So, the PCB Gremlins got to the TritiLED V3.0 board.  The timestamp on the gerber files is at 20:49 local time, making me think that the mysterious PCB-bug-inducing behavior is not limited to post-midnight design sessions.

    I ordered the boards before prototyping the circuit: today, on a breadboard, I found the problem - an input line on the 74LVC1G123 pulled high when it should be pulled low.  I haven't even received the PCBs back yet.  I can rework the three incorrect PCBs easy enough - cut a trace and run a piece of wire-wrap - but it means another order to have a "releasable" version for the coin cell challenge.

    Moral of the story: even the relatively early 20:49 is late enough for the PCB Gremlins to strike.

    Beware.

  • RadioShack Cabinet

    06/24/2017 at 23:44 3 comments

    A local store closed about 10 years ago, and the manager sold me this cabinet for $50. No parts inside, though :( It brings back fond memories of projects in my youth.

    For years, it was behind my 10m target range, and somehow got hit a few times. This mystifies me, because I *never* miss ... there must be a hole in my trap :-)

  • A Review of the OSH Park Jelly Beans

    12/09/2016 at 14:18 5 comments

    I received my latest OSH park PCBs yesterday - some TritiLED boards without integrated battery holders. Inside the envelope was also a package of OSH Park jelly beans:

    I've previously compared the board quality and level of service at OSH Park to that of a few China-based services I've tried (OSH Park wins), so this time, I thought I'd focus on the confectionery aspects of the PCB service.

    True to the made-in-USA-quality branding of OSH Park, the beans themselves are genuine Jelly Belly's: well-regarded beans, indeed. The back of the package displays a prominent "Made in the USA" label:

    Even though the beans were sealed in the plastic, I took the precaution of wiping down the package to remove any contaminants that may have transferred from the PCBs. I'd be more concerned if these were lead-solder HASL boards, but still - I'm a stickler for no food or drink in the lab.

    When I first saw the package in the poor lighting of my garage, I thought the beans were black. It didn't take long to realize that they must instead be purple! Like the PCBs themselves, these beans take on such a rich hue that this mistake is easily made. In better light, they appear quite handsome: deep purple in color, with the classic white "Jelly Belly" logo emblazoned on the side, mirroring the PCB's soldermask and silk-screen. Bravo, OSH Park!

    Upon opening the bag, I detected a sweet, fruity boquet of berries and plums: they could be Island Punch or Wild Blackberry - or knowing OSH Park, a custom purple mix signifying that they're a brand apart. A small bite revealed the expected firm outer skin surrounding a crystallized sweet flesh and a supple inner core. I found the bean to be big, bright, and complex: definitely fruit-forward in character. A second taste showed a not unpleasant jammy flavor - this is an opulent candy. I'm not an expert at jelly bean tasting, but I would guess this is a fine example of the Wild Blackberry style - probably from California.

    I'd like to be able to compare these to the candies sent with boards from other fabs - but alas, no other fab has ever sent any. Therefore, I declare these to be the absolute best candy of any batch prototype PCB fabricator (by default).

    Oh, and the PCBs were excellent as usual. but that's not really news.

    FULL DISCLOSURE: I received a package of jelly beans from OSH Park in a recent order. However, they asked for nothing in return.