Sunday, November 30, 2014

It happened again

Once again, Sure Electronics modified their 32x16 3mm LED display, and this time not only cosmetically.
The two 16-pin shrouded male connectors have been replaced with 10-pin connectors. And the worst thing is that the display now requires 12V for power! Maybe these new displays are intended for use in vehicles powered by 12V batteries. Or maybe designers thought a 12V power source is easier to access than a 5V one. In any case, the display has an on-board DC-DC switching regulator (with XL4013) to make the required 5V.

For someone who needs to replace the older model with the new one, the immediate consequences are:
  • the connector between the driver board (e.g. Wise Clock 4) and the display won't work; connections must be re-wired, probably using an adapter cable;
  • either supply 12V to the board through the connector, or hack the display by soldering the 5V wire directly to the board (see the photos);
  • the holes won't align anymore.

The good news is that the display is electrically compatible with the old one. With the correct re-wiring, the display should work without any software changes.

The following photo shows the testing of the display with the Wise Clock 4 board (and it works just fine).

The display has a series of rail bars that can be used for soldering the 5V power wire, as shown below.

A new design based on this display should (or must) use a 12V power supply. Powering from the USB is not an option any more. This would require a re-design of the Wise Clock 4 board as well (USB connector would be useless now; the FTDI cable won't be able to power the display).


  1. Thanks for the heads-up!
    Did they at least list new display as different model this time? :)
    It does make sense that they went with 10-pin IDC, as most pins were not used, but move to 12V is a bad one...
    I'm fed up with them, and plan to make my own HT1632c based matrix boards for my Xronos Clocks. Got some ICs already and made my own break-out PCB (let me know if you want Eagle files)

    1. The datasheet they point to is the same as before. The only hint that the display is different is a sneaky reference like "Vcc=12V", somewhere in the description.

      There is a need indeed for a competitor to Sure on these displays. Monopoly, especially when parts are off-the-shelf, like in this case, is negatively affecting many.

      Yes, I appreciate if you can share your design of the display.

    2. Wow that is sneaky! I'm glad I did order more displays...
      Here's link to the forum post where I attached eagle files of the HT1632c breakout board:
      Didn't get much further than that yet :)

    3. Thanks.
      I'll take a look and maybe contribute.

  2. Wow, what a royal pain in the proverbial! There must be a more consistent source of similar displays out there somewhere...ot was bad enough that they changed the hole pattern, but changing connectors and voltage requirements and still posting the same data sheet is not a good way to run a business....

    1. One of my reasons for not doing a kickstarter was the dependency on a single supplier.

      Now, I am thinking the display itself would be a good kickstarter idea.

  3. So I've been trying to design my own display, and ran into further issues with Sure... I bought some LE-MM103 8x8 Matrix displays from them and discovered that despite it being described in DataSheet as Common Anode, once I got are actually Common Cathode. I confronted them and they send me Common Anode version. Apparently they make both, with same model number :) I'm having hard time figuring out if I can drive CA LEDs with HT1632c :( Do you know if it's COM pins can be switched to work with either CA or CC LEDs? Datasheet mentions something about N-MOS and P-MOS configuration... Maybe you want to collaborate with me on making custom LED boards? :)

    1. From the datasheet, HT1632 can obviously drive common cathodes. The displays from Sure also use common cathodes. I'm not sure how you would drive common anodes though. Somewhere in the datasheet there is this sentence: "has a common sink total current value of 250mA" which makes me believe it can only drive common cathodes.
      What stage of the design/experimenting are you at?