Tuesday, September 20, 2011

Wise Clock 3 with Duino644

Let's start with a bit of "history".
Duino644 was designed to match with (plug into) the now-discontinued 2416 mono-color LED display from Sure Electronics.
Wise Clock 3 board was designed to plug into the 3216 bi-color LED display from Sure.
Both boards have a similar schematic, based on ATmega644, and they share similar features: RTC (DS3231) on I2C, SD card, piezo buzzer, 3 user buttons.

There are a few differences between the 2 boards:
  • Duino644 has IR receiver, connected on D2, whereas Wise Clock 3 has the Plus button on D2 and no IR receiver;
  • Wise Clock 3 has D11 connected to pin 2 (CLK) of the 3216 display; on Duino644, since the 2416 display does not require an input on pin 2, D11 is not connected.

Our goal is to adapt the "old" Duino644 board to the 3216 bi-color LED display and run the Wise Clock 3 software on it. This is easily achieved by doing the following hardware hacks:
1. connect the processor's pin 17 to pin 2 of the display's connector (red wire in the photo);
2. solder a bridge between processor's pins 3 and 4 (also visible in the photo);
3. cut out the IR receiver.

Now upload the Wise Clock 3 sketch (download latest version from here).
Plug the Duino644 board into the 5mm display, as shown in the photo above, then power it with the USB miniB cable. Surprisingly, the ensemble looks pretty functional and practical as it is: the buttons are accessible at the top (albeit a bit deep), the board is flush with the display, and the power (USB) socket is on the right side.
The enclosure could be a similar pair of plexiglass plates as used in Wise Clock 3. This bigger Wise Clock 3 would be more suitable to be hang on a wall (rather than sit on a desk).

Note that the Duino644 I tested uses DS3231. A version with DS1307 should work the same (except it will show 0 as the current temperature, I think).

As always, feedback is appreciated.


  1. Sweet thanks... But of course I have questions..

    I have the IR sensor installed, and a DS1307 so couldn't I just add the wire for the display and change the code for the button from D2 to D3.. that way I could still have the IR sensor..


  2. Of course you can do that.
    You can leave the Plus button on D3 and change the code in file buttons.h to reflect this.
    Then, IR receiver stays on D2 (with interrupt), but you will need to add the code (from Wise Clock 2) to support it.

  3. Out of curiosity.. how much of the 644 is being used at this point.. how much more can it be pushed and expanded?

  4. I did not find any limitation with the software I had written so far. I think it can handle a lot more.