For this proyect I used Picaxe microcontrollers.
This clock involves all the types of comunication between MCUs i know to use.
It includes: i2c, infrared, paralel, 1 wire serial, and 2 wire serial (data bit-clock).

Step 1: Where Does the Hour Come From???

To begin I used the DS1307 RTC to provide the hour to all the other MCUs. It is pretty esy to use it if you know how to usw i2c communications.

Step 2: Reading the Hour

A picaxe chip reads it (via i2c), transforms the data to bin and sends it via an infrared link ( I used a small acrillic bar to prove if it is posible to replace optical fiver with acrilic for short distance transmissions. And as you can see, it is possible!!)

Step 3: Receiving Data

Next, another picaxe receives the infrared data, changes its format to send it to the MAX7219 driver (digit per digit) to do this i thransformed the number to ascii and substracted 48, so I ended up with each digit in a different variable. and then send one by one using 1 serial cable to the Max72 19 driver.

Step 4: MAX7219 Driver

The max7219 driver does a lot of stuff ( in my opinion) it is resumed here: it recieves the four digits and then send bit by bit to the Max7219 which finaly shows the number

Step 5: Conclusions

The amazing thing is that all this process takes less than 2 secs.

I made the digits by myself, I know that they are not the best displays but I really tried to make an effort to make them as pretty as I could

sorry for not uploading the *.bas files, that's because I have them in my programming computer (the one with the DB9 port :) )

thank you for looking at my proyect

If you found any spelling or grammar mistake, I'm sorry I'm from Mexico and I'm still learnig Eanglish