FabulaTech Forum Newbie
« on: Oct 18th, 2007, 2:43pm »
My application is infrared pc remote control, the output of which not only will control the pc but will also send out infrared signals to control any infrared capable device from the pc. To this end I have cobbled together a chain of software and hardware components the latest, and very crucial of which is Serial Splitter.
First a short technical picture then my questions about Serial Splitter.
1. Home brew IR receiver built as per the specs of Alessio Sangalli of lnx.manoweb.com. Attached to the serial port using DCD RST and GND pins of a straight thru subd9 cable.
2. Winlirc attached to COM1 on the PC to decode individual remote control button pushes. It appears to be the only software capable of reliable decoding, my home brew effort not withstanding.
3. AutoHotkey to tie the decoded button presses to any software on the pc.
4. Custom PHP software invoked by autohotkey to write data to COM1 sending that data to a PIC chip via the TX and GND pins of the same cable as #1. GND is shared. The PIC is mounted on a breadboard right now and conrols 3 LEDs just to prove that the signal gets there. The effect of all this is to make it appear that I can control a computer peripheral with an IR remote control. Therefore, theoretically by extension, when I reprogram the PIC and replace the LEDs with an infrared transmitter or RF transmitter I should be able to control any infrared or RF device I choose from the PC. (Surely someone else has already done this a more efficient manner)
Currently Authotkey is being tied in to marry Winlirc to the PHP application.
Serial Splitter is required because it solves the problem of contention for COM1 between Winlirc and the PHP application. I want only one cable because, ultimately, the IR receiver and (IR or RF) transmitter will be housed together in one convenient unit.
Hope the above was not to windy. Now the Serial Splitter questions.
Within Serial Splitter COM1 is set to 2400 baud, 8 bits, no parity, 1 stop bit, no flow control. This matches the PHP application setting which must agree with the PIC capability, limited right now by a 4 mhz oscillator. Winlirc is optimized at 115000 baud. It seems that sharing COM1 is the best choice. I tried the "split serial ports" option but my PHP application would not recognize the virtual COM. Is that an appropriate choice? Should I have rebooted after setting up the virtual COM? Also, between Winlirc and PHP should I start the program with the lower baud rate first. I had what appeared to be contention problems when I started Winlirc before PHP.
In summary I don't know how to optimize Serial Splitter.
That's enough for now. Thanks in advance for the time you have taken to read this.