ir - infrared remote control — Inferno 1ed

ir - infrared remote control

include   "ir.m";
ir     := load Ir Ir->PATH;    # for real remotes
simir  := load Ir Ir->SIMPATH; # for keyboard simulator
init:      fn(c, p: chan of int) : int;
translate: fn(c: int)            : int;

Description

Programs running with the Prefab module are controlled by an infrared remote control device. If such a device is not present, the system may simulate it from the keyboard by loading the module in file SIMPATH. The Ir module defines codes for representing the remote control keys. These codes are typically sent over the Context.cir channel, which is managed by Mux. (See context - graphics environment in Chapter 11 and Limbo Prefab Module in Chapter 12

init

The init function takes the appropriate actions to initialize the device, and then spawns a process to return the c the codes on the irc channel and p the process id on the pid channel. This is done for both real and simulated devices. The init function is typically invoked once, such as by Mux, and the codes are then multiplexed between the applications. Most programs need not call init.

translate

The translate function converts the device's raw codes into the constants defined by the module. For example, with the simulated remote control, translate('3') returns Three. The translate function is only necessary for programs that need to manage their own simulation of the remote control.

Codes


Code	Description of Code	Keyboard Equivalent
ChanUP, ChanDN	The Channel-Up and Channel-Down buttons	r and c
Enter	The Enter button	SPACE
EOF	An end of file from the remote device. After sending an EOF, no more codes will be sent on irc	None
Error	An unknown or invalid input from the remote device	None
FF, Rew	Fast-Forward and Rewind buttons	k and j
Mute	The Mute button	None
Power	The Power button	Delete key
Rcl	The Recall button. Typical applications do not see this command; instead, the Mux application intercepts the command and reactivates its menu.	x
Record	The Record button	None
Select	The Select button	Return or Enter key
Up, Dn	The Up and Down buttons	i and m
VolUP, VolDN	The Volume Up and Down buttons	t and v
Zero, One, Two, etc.	The digit buttons, 0 through 9	corresponding numeral keys

Examples

Application programs using the remote control run under mux, which creates a graphics interface for the application. This includes channels to the Mux program and to the Ir device: Context.ctomux and Context.cir. The following example establishes communication with Mux and then reads Ir commands until it sees Enter.

implement Command;

include "sys.m"; 
include "draw.m"; 
include "ir.m"; 
Command: module 
{
  init: fn(ref Draw->Context; list of string);
};
init(ctxt: ref Draw->Context; argv: list of string); 
{
  sys:= load Sys Sys->PATH;  
  # Tell mux to start sending input.  
  ctxt.ctomux <-= Draw->AMstartinput;  
   for(;;) {   
       key:= <-ctxt.cir;   
        sys->print("command %d\n", key);   
         if(key == Ir->Enter)    
              break;  
   }  
  # Tell mux this thread is going away.  
  ctxt.ctomux <-= Draw->AMexit; 
}

Programs such as Mux that drive the remote control directly must load the appropriate module and initialize it. This example uses the absence of a simulator module to infer that a real remote control is available.

implement Irtest; 
include "sys.m"; 
include "draw.m"; 
include "ir.m"; 
Irtest: module 
{  
   init: fn(ctxt: ref Draw->Context, argv: list of string); 
}; 
init(nil: ref Draw->Context, nil: list of string) 
{   
    sys:= load Sys Sys->PATH;   
    # First try the keyboard Ir simulator.   
    # If that is not present, use Ir directly.   
    ir:= load Ir Ir->SIMPATH;   
    if(ir == nil)     
        ir = load Ir Ir->PATH;   
    if(ir == nil){     
        sys->print("Ir module not loaded: %r\n");     
        return;   
    }   
    irc:= chan of int;   
    pid:= chan of int;   

    if(ir->init(irc,pid) < 0){     
      sys->print("Can't initialize Ir device: %r\n");     
        return;   
    }   
      <- pid;
      for(;;){     
              irval:= <-irc;     
      sys->print("command %d\n", irval);   
    } 
}

Museum

ir - infrared remote control — Inferno 1ed

ir - infrared remote control

Description

init

translate

Codes

Examples

See Also