Vermes
Advanced Member level 4
It is a improved version of a HDDClock with a special emphasis on aesthetics.
Principles:
The purpose why this clock works is easy. A rotating plate has a cut slot. Under the plate there are RGB LEDs, which act as a steady illumination. Properly modulated LEDs light gives the effect displayed on the picture above.
Motherboard:
The driver was based on Atmega128 microcontroller. That is why a lot of peripheries is needed in order to get easy with the application, which is written in C. As a real-time clock, DS1307 system was used. The engine is controlled by dedicated TDA5140A driver working in a standard configuration from datasheet. The device was equipped with RS232 interface. After completing the elements, it is easy to load a new program by using MegaLoad bootloader. The controlling is possible by a small universal remote control which is working in RC5 standard. PCB itself is made by photochemical method, irradiated by the envelope method.
Back light:
As a back light, quite bright tricolor SMD LEDs were used. They were placed on little plates which were then linked in a chain. Additionally under the plate there is a ring made of white paper, which contrasts the light very well.
Synchronization:
Synchronization of the whole system is assured by the reflective sensor. Unlike the slot sensor, it can be placed in front of the edge of plate. That is why it hides in the housing and isn't visible from outside. The pulses from the sensor hadn't been clear enough, so they needed to be shaped by a comparator with hysteresis before they were placed on uC.
Housing:
The housing is made of original disc housing. But it's necessary to make some masking details. They were made of special kind of plastic, which name is reynobond. It was painted with black spray. The front was made of 2mm plexi. Under it, some special graphics were placed. Power and programming socket is in the back of the device. Hole to the IR receiver was drilled on one side, in order not to spoil the look of front panel. Still the system reacts properly to the remote control's commands.
Link to original thread (with some useful attachments) - HDDClock – zegar z dysku twardego