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[Reply #15 on:]

Thanks for the X10 link. Total news to me. (I already have an X10 receiver that I use, so I am half way there already

That's right, a screw-in light fixture, like a light bulb. I think the glass dome I mentioned earlier will fit well in here, but used upside down (with the wooden base part on top, and a light bulb screw attached to it). We would need to find a way to secure the dome to the wooden base. A small power adapter (the "USB wall wart") should fit in the dome as well. I am thinking that even a glass jar can be adapted for the job, and it would be easier to attach the screw to the metal lid.
A servo will be required to rotate the display (to position it for the best viewing).
Also, a set of high intensity LEDs could be installed opposite to the display matrix, and used as directed, remote-controlable, light source. (now that this Arduino contraption is screwed where the old light fixture was).

I see a few challenges that need to be resolved:
- mic and buzzer are inside the jar/dome/bulb now;
- IR receiver should be reachable by remote even when the whole thing is rotated 180 degrees and not facing the remote (can you have 2 IR receivers in parallel?);

And, listen to this: if an accelerometer is included (or some positioning sensor), then the contraption can be screwed up in the ceiling (hanging down) or screwed down in a desk lamp, and the display will still show the text in the correct stance.

What do you think?

[Reply #16 on:]

A bit of an update on the slow progress of my version of "Life Clock" (I could not resist  :-[):

- I switched to atmega 328, $2 more expensive, but lots of memory for future expansions;

- I was able to store my character set definition (8 bytes per character x 96 characters) in the local eprom (1K now); so now the 24LC256 eprom has only messages (32K, aprox 16 book pages);

- implemented "sleep mode", through remote control; in sleep mode, the whole thing is taking now 3.5 mA (an off-the-shelf arduino takes at least 15 mA in sleep mode). For this purpose, I had to build a custom arduino board, basically a protoshield (the small/short version) with only the processor on it. I eliminated the power LED (20 mA wasted right there), the FTDI chip, and the voltage regulator and the reset button (I always use a shield that has a reset button).

- I am still waiting for the LED matrix shields from seeedstudio; they should be available for everyone soon;

I think there would be a need for yet another arduino-compatible board, one similar to Arduino Pro from sparkfun, but with an atmega 328 on it and no LEDs, plus some other provisions for sleep mode.

[Reply #17 on:]

BroHogan,

Could you send me a copy of the schematics and code? I'm really interested in the code for loading and reading the eeprom for font data. I'm looking at making a sign, but the main part i'm hung up on is the way to take a message and lookup the font data in eeprom. Nice project!  

[Reply #18 on:]

More progress! Today I received the shields from seeedstudio. Everything worked like a charm, no glitches, no surprises, almost unbelievable!

This is how it looks like:



More photos here:
http://flickr.com/photos/11567579@N05/3293540285/in/set-72157612254405335/

I added a (poor quality unedited) video as well:

[Reply #19 on:]

That looks amazing. Great work. I just posted the other day asking for an update on the RainbowDuino http://www.seeedstudio.com/blog/?page_id=187

Can I assume that you are using what will be that product?

[Reply #20 on:]

Thanks.
I reckoned that using a glass dome would be suitable for a clock. Plus, being transparent, it gives access to the IR receiver.

No, I did not use the seedstudio's RainbowDuino. I designed my own and I got it manufactured by them. (My previous posting has a link to the photo of the little black board, the LED matrix shield).

I can provide more hardware details if you are interested.

[Reply #21 on:]

Yes, more details please!  

Did they do this for you as a one-off, or are they going to manufacture your design?

[Reply #22 on:]

Seeedstudio offers this so called "Propaganda PCB service" , check it out at http://www.seeedstudio.com/forge/wikka.php?wakka=Propaganda.
You email them the Eagle board file (must be open source) and they send you 5 boards for $30.

I had the shield for the 8x8 RG LED matrix made by them.
Theoretically, you should be able to buy the boards I designed from their website, although I did not see them posted yet. Just ask. Anyway, I just finished revision 1.1 and I will get it manufactured in bigger batch.

As for the arduino, I used one made on the small prototype shield, since I wanted all the boards in the sandwich to have the same dimensions, and also because I wanted to eliminate some components (from the original arduino) that I did not need and which took some juice out of the batteries. I almost finished the design of this board (waiting to get a few more components). This should be also available soon.

After much thinking, I came to realize that Mr. BroHogan's original "sandwichduino" is the best approach for this kind of project. And coming up with a case is as challenging. The glass dome I used is not cheap, but the cherry case required even more effort, I assume.

The project is still in development, since I plan to add a few more things, as suggested in previous postings here.

[Reply #23 on:]

Here is a new version of the clock project:


The idea was to be hung on a wall. I had a few options for the case, but they would require some fine work and skills, so I opted for the easiest and quickest, a bent piece of plexiglass (clear acrylic).
The circuitry fits on one custom board. It should have been black, but I forgot to ask when I ordered it.

[Reply #24 on:]

My friends asked for a larger display. Using the same LED driver circuitry, I replaced the bi-color 8x8 LED matrix with two, single color (red), 8x8 LED matrices. The result is shown below.



(The case, bought from a photo shop, was designed for storing 4x6 photos. It has a hinged glass door, held in place with small magnets. It can be also hung on the wall (this has become an obsession, it seems :'())

[Reply #25 on:]

wow, i'm impressed. I like how your project got increasingly more complicated!

as a sidenote... any figures in terms of total cost?

[Reply #26 on:]

The good thing about using 74HC595 is the price. The bad thing is that most of the digital outputs are used, there is no room for other add-ins like an ethernet card

Not sure what you mean by that. You only need 3 pins to drive 74HC595's.

[Reply #27 on:]

Mike,
My approach uses a combination of 595 (2 pieces) and direct outputs, as shown in the schematic here:
http://www.flickr.com/photos/11567579@N05/3178651230/in/set-72157612254405335/
I could have used a third 595 to drive the rows and save some 5 outputs.
Since I dropped some "requirements", there are still 3 analog/digital pins available (for alarm/buzzer/x10, for example).
As for the input pins, I only need to use two: one is for IR receiver, one for a redundant push button. I am trying to funnel every user input through the remote control, including setting the time and the alarm.

Regarding the cost: the parts, PCB included, would run between US$60 (digikey) and $75 (sparkfun).

[Reply #28 on:]

I see. Nice project by the way.