GKOS IR Communicator

The PIC 16F876 microcontroller together with the GKOS keyboard and
 a low-cost LCD unit make a very compact infrared communicator.

This device both sends and receives GKOS IR data. Text communication (chat) between two devices is possible. A single device can be used for learning and practising GKOS typing, or can function as a remote control for a PC if there is a GKOS PS/2 interface connected to the PC mouse/keyboard connector ('keyboard as mouse' operation included) or the more recent GKOS IR receiver on the COM port of the PC..

- Receives and transmits GKOS IR signals (as specified for the GKOS remote controls)
- Local (transmitted) text is shown on the second line of the LCD display, received text on the first line
- Manages single chords and overlapping chords, as well as chordons
- Both FIN/SWE and US/UK GKOS keyboard layouts supported (ALT 123-ABC to change)
- Word shortcuts (but not the latest version of them) are available on the national part of the the US/UK keyboard layout
- Turns off power automatically after 5 minutes of inactivity, press E or F key to turn power back on

Software: glcd18.hex, glcd18.asm. The automatic power-off is now also included. Better key polling.

Take care with the 3.9V zener. It shall be 0.5 watt or of somewhat lower power to give 3.9 V at a low enough current level. Test first with a lower voltage battery (4,5 V...6V) that the voltage over the zener diode gets near 3.9V (so that the PIC power voltage will not get too high, 5.5 volts maximum). The LCD unit type is Optrex 16249 (2 lines of 16 characters) and it has the standard 14-pin interface, compatible with many other displays like this (those including the HD44780 or similar control IC).

More advanced (display control refinements) software may become available later. The schematic works fine and changes to it are not probable. Pins 2 and 3 are reserved for an optional mouse input. - 19 Dec 2004

Page created: 2 April 2004  -  updated 19 December 2004, 26 March 2006