lpt

node-lpt

High-level bindings to parallel port for node.js.

Important: this module works only under linux through the parport driver, so you might need to compile kernel or modules (on gentoo mostly).

Installation

$ npm install lpt

Usage

var lpt = require('lpt')
  , port = new lpt.Port(0, 'byte', false) // open /dev/parport0 with forced `byte` mode set
  // , port = new lpt.Port(0) // the same
 
console.log(port.data) // read data register
console.log(port.status.busy) // get /BUSY pin status
 
port.data = 123 // write data register
port.control.init = true // write to control register

API

Constructor receives the following parameters:

• port number
• parallel port mode - optional. Can be:
  • spp
  • nibble
  • byte - default
  • epp
  • ecp
• negotiate port - optional. If true will try IEEE 1284 compliant mode negotiation.

Port class provides next fields:

Field	Type	Description	Read/Write	Pin num
data	byte	Data register	R/W	2..9
control.init	bool	INIT	R/W	16
control.select	bool	/SELECT_IN *	R/W	17
control.autofd	bool	/AUTO_FEED *	R/W	14
control.strobe	bool	/STROBE *	R/W	1
status.ack	bool	ACK	R	10
status.busy	bool	/BUSY *	R	11
status.error	bool	ERROR	R	15
status.select	bool	SELECT	R	13
status.paperOut	bool	PAPEROUT	R	12
-	-	Ground	-	18..25

*Note that this pins are inverted by node-lpt itself

**You can read control pins only after you wrote something to it. Before that moment you can't rely on pin status

Useful links

• Standard Parallel Port
• Using in Linux
• Parallel port interfacing made easy
• ECP Description

License

MIT