raspberry pi で、MCP23017 の入力ポートを使う Node.js 版

mcp23017_node_input.js

#! /usr/local/bin/node
//
//  mcp23017_node_input.js
//
//                  May/31/2017
//
// ------------------------------------------------------------------
function read_proc (wire)
{
    wire.readBytes(0x13, 1, function(err, res)
    {
    console.log (res)

    console.log (res[0].toString(16))
    console.log ("*** end ***")
    })
}

// ------------------------------------------------------------------
console.log ("*** start ***")
var i2c = require('i2c')
const address = 0x20
var wire = new i2c(address, {device: '/dev/i2c-1'})
    // point to your i2c address, debug provides REPL interface 

wire.writeBytes(0x01, [0xff], function(err, res)
    {
    wire.writeBytes(0x0d, [0xff], function(err, res)
        {
        read_proc (wire)
        })
    })

// ------------------------------------------------------------------