www.gkos.net
Connector side - IR Receiver side
Old software:
PIC Software: gpda100g.hex (.asm
- default mode = GKOS IR byte
mode) - 9 Nov 2005
PC Driver software: gdrv21c.exe - 26 May 2005 - (Beta
/
9 Nov 2005: gdrv22beta.exe)
New
recommended software (PIC
hex file and PC
Driver - 21 March 2007):
PIC Software: gpcr102.hex (gpcr102.asm)
PC Driver gkosw (Both QWERTY
SDF/JKL input and COM port input from PIC)
This circuit connects the GKOS keyboard to the COM port of
the PC either directly or by a wireless infrared link. No external
power is needed. If your PC (e.g. laptop) does not have a serial COM
port, purchase a USB/Serial port converter cable.
Use the Universal
GKOS IR Keyboard
of Building Project 3 for IR
transmission, or you can use the GKOS IR keyboard+mouse implementations
of Building Project 2 (Remote 1 or 2). A GKOS keyboard can also be
connected
directly as shown in red above. In the latter case, the keyboard
consists only of the six switches (GKOS keys) shown. - The
operating mode of the transmitting remote Universal GKOS IR Keyboard
can be either GKOS Chord IR mode, turn on
by [SYMB] [Ctrl] c [ENTER], or GKOS
Keycode IR mode: [SYMB] [Ctrl] g [ENTER]. The
Chord IR mode (sending keyboard status continuously) is more robust to
IR interference, like IrDA signals from laptops, than Keycode IR mode
(one byte per character).
The PIC software is the same as that for the
Universal GKOS IR Keyboard. Only the sleep function has been disabled
and the default mode has been changed
before assembling asm to hex (see around line 722 of the asm file).
Both mouse
and keyboard functions are supported, as well as chordons and 59
shortcuts. All three types of GKOS IR packets can be received (Chord,
Keycode and Mouse Packets). The driver is for Windows
95/98/NT/2000/XP OSs.
This circuit has
been tested on a Win2000
laptop that has ±6V signal levels
on
TXD/DTR/RTS
lines and on a WinXP desktop with ±11.5V signal
levels, both when
unloaded, and ±5.7V and ±8.7V when loaded
by this circuit. Operation was checked also on two more laptops (Win95
and Win98 OSs). The interface and the driver
(gdrv21b.exe up) operated great on all.
The zener diode must be of low
power type reaching its nominal voltage
at low current levels. Its second function is to stop negative voltage
from reaching the PIC while the COM port is closed (DTR off: laptops
0V, desktops -11.5V). Be careful with
your solderings
and
joints and double-check everything before connecting to the PC!
Please note that the left-hand part of
the schematic, i.e. power feed from the serial port
and the voltage level
adjustment from PIC to RS232, has a very
low component
count compared to circuits
commonly proposed for these purposes on the internet. Nevertheless,
this design works
fine with
RS232
signal levels typical for
laptops and desktops.
Keywords:
PC serial COM port RS232 connector for PIC 16F876 infrared receiver
interface with no external power source. IR PIC power feed from serial
port.
Seppo Tiainen 18
August
2005, updated 7 March 2006, 7 May 2006, 21 March 2007.
Character
set: