MAX7219.js
function(limit, callback) {
    if (limit < 1 || limit > 8) {
      throw "Invalid scan limit number";
    }
    this._shiftOut(MAX7219._Registers.ScanLimit, limit - 1, callback);
  }
function(limit, callback) {
    if (limit < 1 || limit > 8) {
      throw "Invalid scan limit number";
    }
    this._shiftOut(MAX7219._Registers.ScanLimit, limit - 1, callback);
  }
function ( limit , callback ) { if ( limit < 1 || limit > 8 ) { throw "Invalid scan limit number" ; } this . _shiftOut ( MAX7219 . _Registers . ScanLimit , limit - 1 , callback ) ; }
Sets how many digits are displayed, from 1 digit to 8 digits.

@param number limit
The number of digits displayed, counting from first to last.
E.g., to display only the first digit, limit would be 1.
E.g., to display only digits 0, 1 and 2, limit would be 3.

@param function callback [optional]
Invoked once the write to the SPI device finishes.
Sets how many digits are displayed from 1 digit to 8 digits .