Weird errors

Master Handler

SPI1.setup({sck:B3, miso:B4, mosi:B5});
var nrf = require("NRF24L01P").connect(SPI1, B6, B7);
function onInit() {
  nrf.init([0,0,0,0,2], [0,0,0,0,1]);
}
onInit();

setInterval(function() {
  nrf.masterHandler();
}, 50);

function send(command){
  nrf.sendCommand(command, function(r) {       
    print("=="+r); 
  });
}

Response is:

>send('one')
=undefined
==one on and volts 0.05297932402
>send('two')
=undefined
>