Hi to all
Could be a YAC (yet another clock), but it's all DIY... take a look, it uses a RTC to keep the time, a Maxim 7219 to drive a 7 segment display, a Max232 to load new sketch. The pages are in italian ::), a bit of google translate could help...
http://mnicolato.altervista.org/arduino/rtcduino.htm
Have a good night (me too)
Marco Nicolato
Arduino Rocks
Nice looking hardware and software. Very well done. Bravo!
Looks really good. Well done mate! 
That's a clean looking layout and on Vector board! Nice work.
(* jcl *)
Cavolo, compliment... ehm...
Great work, man 
That looks pretty cool... Anyone got any ideas about the random characters displaying?
Mowcius
Have you ever computed the current draw of the RTCDuino?
You would probably need a wheelbarrow full of 9 VDC batteries to keep it running for a year!
A fully new Alkaline battery is rated ~ 500 mAH ---> per manufacturer Duracell/Energizer/Rayovac
The 9 VDC battery is used for very low current draw.
Below is the some testing and ratings - the higher the discharge rate the lower the mAH.
9 vdc Alkaline battery has approximately 100 ma discharge rate @ 310 mAH
500 ma discharge rate @ 170 mAH
1000 ma discharge rate @ 90 mAH
The Arduino "Idle ma. draw" is ~ 25 -35 ma
The LED 7 segment display digits for your clock consumes a lot of power even with the digit multiplexing from
the Maxim 7912 chip.
BTW ... That flickering is probably due to the horrendous current discharge of the 9 VDC battery!
Anyone got any ideas about the random characters displaying?
BTW ... That flickering is probably due to the horrendous current discharge of the 9 VDC battery!
That's intentional. I don't know WHY it's intentional, but it is. (It might be explained in the Italian?) See the
void crazyDigit(int digit, int ms)
routine at the bottom of the code, and the places from which that function is called.
Yeah well I couldn't understand the italian even with google translate...
If the random characters are intentional then I don't see why either...
Maybe if it's meant to seem slightly broken. Then I think that it should flicker and turn off for a bit before flickering and turning back on...
Mowcius
Hi to all
Your questions are correct, I was too hasty to put online the work, some explanation could be added !
In the video I've powered RTCDuino with a 9v battery to show a full stand-alone system, without any cable going out from the screen.
Indeed this performance killed out this poor battery, but it was for the science ;D (actually it is powered with a power adapter)
The random display flickering is intentional to give a crazy/broken look (mowcius is right). Needless to say, it could be improved, or removed at all.
(see code:)
// show radomly some crazy digit
if (random(0,1000) > 900)
crazyDigit(random(0,6), 200 );
if you change 900 to a greater value up to 1000, the "crazy" rate will decrease as you want, or if you delete these two rows, the clock will be regular (and boring)
Bye !
Marco Nicolato
Maybe have the digits flickering on and off from one side to the other every so often so it looks like slightly more controlled flickering rather than it looking like it's dying.
The TNT idea posted on the website would be cool, maybe not even some kind of motion sensor, you could just have a capacitance sensor so that it goes crazy when you touch/get near it... That wouldn't cost a load like a motion sensor of some kind...
Mowcius