Specification:
- Display: Six cold cathode neon readout (nixie) tubes Z573M, (or ‘digitrons’, as we call them here)
- Time: Radio DCF77 module receives precise German time, backed up by a 32.768kHz watch crystal.
- Remote control: infra-red (IR) sensor, software decoder for Sony remote controller I’ve got
- Processor: AVR ATmega32 (8-bit, 32kB FLASH, 2kB RAM)
- Storage of voice samples on SD card (e.g. 1GB) with FAT16/32 filesystem
- Sound converter: 12-bit DAC with SPI interface (using MCP4921)
- Amplifier: 1.5W (using TDA7233)
- Debug: UART/RS232, AVR ISP interface
All the resources–software source code, schematic, and PCB layouts–are on github: https://github.com/jsyk/Talking_Clock
Some more detailed description on my web page: http://www.jsykora.info/?page_id=240