MPRC hardware is split in two pieces as sown bellow:
decoder is the "brain" behind the project, it
decodes RC data and send scancodes to keyboard port, it's also where
the configuration is stored. It was made to stay inside the computer
case and to be powered by PSU's +5V line. Three easy to find cheap ICs
are needed to build it:
- MAX232: A TTL/RS232 logic level converter.
- CD4066: Quad anolag bilateral switches being used to select witch
hardware will comunicates with the keyboard port, MCU or Keyboard.
- PIC12F629 or PIC12F675: Microcontroller unit (MCU), where the
firmware and the configuration are stored and the most important IC on
small hardware made to stay near the tv or the device you want to
control. It's composed of three pieces:
- An infrared light detecting unit for remote controls with
internal 38KHz B.P.F. and CMOS logic level output.
- CD4049: CMOS HEX inverting buffer to boost the signal.
- LM7805: +5V DC voltage regulator.