As my entry for the gift exchange, I made this multi-format clock . A lot of people asked me to write an instructable about it so here it is.
As said in the title, this clock has multiple ways to display time.
The four way of displaying time are:
3 Collum binary: A binary collum for the seconds, one for the minutes and one for the hours. (and inverted)
6 Collum binary: A bit easier to read. Two collums for hours, minutes and seconds. (and inverted)
‘Normal’ decimal: Scrolling
The original clock had a backlight too, but I didn't include that in this Instructable.
The clock can be powered by USB, wallplug or via the programming link.
Step 1: What Do You Need to Build This Clock.
What is needed:
- An Atmega16
- A 8*8 ledmatrix: I used one with 5mm dots
- A DS1307 Clock
- A 32768K Crystal
- A CR2032 Battery + Holder
- A USB B Connector
- A Powerconnector
- 3 Buttons
- 3 1.5K Resistors
- 2 4.7k Resistors
- 4 sets of 1*8 male headerpins and 4 feamale counterparts
- 1 set of 1*4 Male headerpins and a female counterpart
- 1 set of 1*4 male headerpins 90degr.
- A 5*2 connector for the programming (optional)
- A 7805 powerregulator
- A 100nf capacitor
- A 10 uF capacitor
- A 100uF capacitor
- Some spacers
Other stuff you need:
- Stuff to make PCB's
- Soldering Iron and solder
- Heat-shrinking tube
Step 2: The Matrix Adaptor-board
I made this PCB to make life easier. On a 8*8 matrix the row and collum pins are mixed up, so I used this board to make a set of 8 row pins and a set 8 collum pins.
They are set in such a way, that they match with the ports I want to use on the Atmega16.
As this is a one-sided PCB, the pins need to be soldered on the bottom side. To make sure that they are long enough to fit, I pushed the small side of the pin until it leveled with the black plastic (see photo). Then they are inserted in the appropriate holes and soldered.
Step 3: The Button Board
This is simply a small board that houses the 3 buttons and a 90degr connector.
Step 4: The Main Board
The main board houses the atmega16, the DS1307 and all the parts needed to make those work properly. It also houses the 3 1.5K resistors needed for the buttons, as well as the buttonboard itself.
The pcb-layout also indicates the location of the 3 spacers. Just drill on the crosshairs.
Step 5: The Powerboard
As said in the intro, the powerboard is slightly different than the one in the original clock.
I removed the backlight and the attiny 45 that was there to controle it.
It now houses the USB-connector, the battery for the clock, a connector for a wallplug, a 7805 and the needed capacitors. I used some flatcable connected to a female header to connect this board with the main board(see photo).
Step 6: Programming
I added the hex-file for this colck so that you can program it yourself.