SparkFun will be closed Nov 26th and 27th for the Thanksgiving holiday. Orders placed after 2:00pm MT on the 25th will ship out Monday the 30th.


Member Since: May 30, 2010

Country: United States

  • Mon crayon est jaune et large. Ok, it’s not jaune, but still…

  • Bob shows off his disposal method for expired Sugru packages.

  • Ah well, didn’t win this year either. On the other hand, Captcha gave me plenty of ways to name my band. I think Orklet Studies is a great choice.

  • The idea of a personal rating system is not new in this book - it was also pretty integral to the story in Cory Doctorow’s “Down and Out in the Magic Kingdom” - in which “Whuffie score” was the personal rating system, and which the score is instantly accessible to everyone, due to ubiquitous use of ocular implants and augmented reality. Imagine the scores floating above the heads of everyone you meet!

  • Kinks have been worked out. All leads are in the proper place relative to the silkscreen, and the voltage multiplier which provides sufficient dropout headroom for the 5V regulators has been redesigned with 1000uf caps, which I verified resolves the current limitations with the previous 100uf design - you can now power the whole thing, CRT, o-scope and all, from a single AC transformer. This board has been uploaded to BatchPCB for you to have manufactured for yourself at this link.

  • OK, I’ve got my first board back and the circuit is working well, although I’ve got a few kinks to work out so the board will need a revision before I unleash it on the public.
    1: Minor layout errors: 1 5vAC input was not connected to the rest of the circuit, easily fixed with a wire.
    2: DIPTrace had lead numbers reversed for the ZTX458 and the +/-5V regulators. Easily fixed by desoldering and turning the parts around, but this needs to be fixed to avoid magic smoke release for future users.
    3: The 150ma 7805 output is sagging for some reason to under 3V when attempting to power both the onboard TL082 op-amp and the O-Clock board via the USBVCC 5V input. I don’t quite understand why, there ought to be plenty of current capability remaining, so this needs further investigation. An alternative is simply to power the O-Clock separately from the CRT board via a wall-wart and its barrel jack, which is how I have it working now. This requires further investigation - I’m not an EE, so it’s probably something obvious, but at the moment I don’t quite get it. If anybody would like to help, I’m happy to send my schematic. :-)

  • Sorry: try this link:
    The board is still available. (This is a revised version with mounting holes and reversed header layout. See the notes for the project on the product page on BatchPCB.)

  • I laid out a board for BatchPCB manufacturing that will drive a small CRT based on the Jon Stanley design - it’s claimed to work well with this clock. If anyone’s interested I will make it public on BatchPCB (around $30 for single quantities) along with the BOM of materials from Digikey to solder onto it (another $20ish) - Then add a Hammond 270X transformer (~$45), and a CRT of your choice: Sphere Research in British Columbia has lots of good choices that should work well with this setup such as the 3RP1-A, which I’ve successfully used in a different design.

  • See http://batchpcb.com/index.php/Products/54792 (edited!) for a reasonably compact PCB design to control this matrix with the microcontroller of your choice, 5v or 3.3v power, and 4 data lines (serial clock, register clock, master reset, and data in.) Data and power in/out are provided on 2x5 IDC headers. The board is chainable so you can create a wider display with multiple LED matrices.
    Blog w/pics, video of this board (and a Parallax Propeller project to make it into a scrolling text display/clock at http://forums.parallax.com/entry.php?118-My-expandable-full-RGB-blinky-LED-matrix-with-color-fading-scrolling-text.

No public wish lists :(