I don't know what others think of the LED displays from Sure Electronics, but for me they seem to offer the best performance/price display option out there.

I recently developed a new version of Wise Clock, that loads the text from SD card and displays it on the mentioned LED display. Arduino with ATmega 328 could barely cope with the load (pun intended): the 2KB of RAM was used to the hilt. So I decided (as suggested) to switch to ATmega644, used in sanguino, which has 4KB of RAM. In the process, I also decided to design a board that would plug into the LED display from Sure Electronics, hence the name "Wise4Sure".

I am wondering how useful for the others this Wise4Sure board would be.
Some of its features are:

  • ATmega644P (at 16MHz) as its core;
  • directly pluggable into either of the 2 (16x24 or 8x32) LED displays from Sure Electronics;
  • display selectable from switch;
  • SD card socket;
  • RTC (DS1307) with backup battery;
  • 24LC256 EEPROM;
  • FTDI connector;
  • powered from an USB type B connector;

A working prototype can be seen in this video:

Here we are, working on that board, as shown below.


Your comments are appreciated.

Integrated SD socket and FTDI are useful to me. LED display sockets ... not so much. RTC w/backup wouldn't hurt (or help). As for memory/RAM, the more the merrier.

I'd prefer it to be self-contained so I could power it with a battery instead of only thru USB, even if it was just an entry pad/pin to take power from a regulated 5v source, but beggars can't be choosers. (I just want FTDI for an alternate data source from a PC instead of from an SD card -- the user could choose the data source from day to day.)

Will be watching this thread with interest.

I gathered a few more comments/suggestions, which I will try to incorporate into the board:

  • IR receiver;
  • breakout connectors/headers for the other remaining pins;
  • 2-pin power connector (JST, molex) for battery;
  • it would be nice to have pin-compatibility with Arduino shields;
  • a connector for XBee adapter;

Here are a few explanations about the design goals:

  • Wise4Sure is supposed to fit snugly and firmly into the 16x24 LED display; one connector carries the signals for the display, the other has just mechanical purpose;
  • for the 8x32 LED display, only the signal connector gets plugged into the display;

Back to the "drawing board".

I'd suggest powering the SD card from a digital pin (if possible). My experience so far, is that sometimes the power must be removed from the card to get it working again (i.e after loading a new sketch)

If you have control over the power, it gives you some options.

Thanks for the advice. This is how the card on the SD shield from Libelium is powered. I always wondered why, cause I never experienced this kind of problem (power must be removed from the card).

Another "improvement" I am going to make is an LED on the CS line, kinda like the HDD LEDs in PCs :slight_smile:
It will also help debugging.

PS This sounds very "Star wars" -y :sunglasses:

If you have control over the power

Just another way of saying "Use the force" I guess.

I managed to design the board so that, besides being the undershield for the Sure Electronics LED display, it is also usable as the base for Uzebox.


Some features are:

  • ability to solder either USB type B or miniB connector (for power);
  • ability to solder either resonator or crystal + 2 capacitors;
  • ability to solder either SD socket or microSD socket;
  • configurable (through jumper) for either Sure LED display 8x32 or 16x24;
  • all 4 ports connected to headers; this is how the board becomes the base for the uzebox; a uzebox shield (with AD725, RCA connectors, audio etc) is to be plugged into these 4 headers; (for uzebox, a different crystal needs to be used though)
  • power switch;
  • optional IR receiver;
  • optional EEPROM (either SMD or TH);
  • optional RTC (either SMD or TH) with on board backup battery;
  • 2-pin molex (or JST) connector for power;

Do you see any obvious (or subtle :)) mistakes?
Would this be of any interest to others?

If you decide to sell it as a kit, I would really consider buying it! :smiley:

Try to fit a simple amplifier like tha WaveShield so it can play some .wav files (Alarm?)!

I thought of that (playing wave files). A better solution would be a(nother) wave shield, using ladyada's schematics. It would plug in the 4 headers and have the DAC, an amplifier and a speaker. I did not try a sketch that includes playing the wave files, but I think it should work (if nothing else is running).
As I mentioned earlier, another shield should be the "Uzebox shield". More on that later.
I will put together a kit as soon as I will have the boards made.

For SD card access and MP3/WAV playback, I'd suggest using our uMP3 Playback Module.

You can offload the heavy lifting of SD card access, and you'll get music for alarms/listening. I think it would work great with your original WiseDuino too. (Your Wise Clock with the dome case looks great too!)

The display looks nice and bright... although, PWM'ing the LEDs for late night dimming would be a nifty feature.

I've written an Arduino library for the uMP3 already, but haven't had the chance to upload it yet. You can have a look at the uMMC library I've created to see the capabilities of the SD card access.


You can pick up one from RobotShop or from one of our distributors.

I'll be putting up the uMP3 library shortly.


That (uMP3 Playback Module) looks like a pretty powerful machine in itself.
It would be very nice if it was an Arduino shield (pluggable/stackable, that is), I am sure many would be interested. In this case (Arduino shield), a small speaker would be useful as well.

What is the "uMP3 Chipset"?

The more I read, the more I like it. This looks like a great toy.

Funny you should mention a shield... I bet you can't guess what I'm working on right now? :wink:

It won't have a speaker on board (people are picky about their speakers), but it's easy to add a small one if you wanted.

The chipset is for companies who want to integrate the uMP3 onto their own boards.

Once I get the new board done and off to fab, I'm going to put up as many examples with the Arduino and uMP3 as I can.

I'd really like to see it in use on one of your clocks. It would be pretty sweet to have a alarm clock with music from an SD card. With scrolling lyrics. Something to wake up to in the morning. "Workin' nine to five..."


I received the boards.

And this is the assembled board, which worked (amazingly) right away.

Details here:

as long as the prices are good

For US$64 ($54 for Duino644 + $10 for LED display) you can get a nice and useful device. And that includes a more powerful (than ATmega328) microcontroller, SD card socket, real time clock, EEPROM, IR receiver etc. Also, potential for a uzebox gaming console.

Got some enclosure, simple yet effective: two laser cut plexiglass squares.


Here is the enclosure in some more details (video):

Nice job, the black PCB is great!

I'm a big fan of the Sure LED displays as well. Where did you find the female headers, though?


I make them, by cutting the larger 2x40-pin ones.
Did I mention I offer a kit for sale?

They say necessity is the mother of invention :wink:

Thanks for the heads up re the connectors and the kits!