A braille display driver for NVDA. Braille is displayed on screen. Save this file to the 'brailleDisplayDrivers' folder in your user config (`%appdata%/nvda/brailleDisplayDrivers`) directory or in `source\brailleDisplayDrivers\` directory in your repository.

brailleViewer.py

#brailleViewer.py
#A part of NonVisual Desktop Access (NVDA)
#Copyright (C) 2017 NV Access Limited
#This file is covered by the GNU General Public License.
#See the file COPYING for more details.

import wx
import gui
import braille

NUM_CELLS = 40

class BrailleViewerFrame(wx.MiniFrame):

	def __init__(self):
		super(BrailleViewerFrame, self).__init__(gui.mainFrame, wx.ID_ANY, _("NVDA Braille Viewer"), style=wx.CAPTION | wx.RESIZE_BORDER | wx.STAY_ON_TOP)
		self.Bind(wx.EVT_CLOSE, self.onClose)
		mainSizer = wx.BoxSizer(wx.VERTICAL)
		item = self.output = wx.StaticText(self, label=u"\u2800" * NUM_CELLS)
		font = item.Font
		font.PointSize = 24
		item.Font = font
		mainSizer.Add(item, proportion=1, flag=wx.EXPAND)
		mainSizer.Fit(self)
		self.Sizer = mainSizer
		self.Show()

	def onClose(self, evt):
		if not evt.CanVeto():
			self.Destroy()
			return
		evt.Veto()

class BrailleDisplayDriver(braille.BrailleDisplayDriver):
	name = "brailleViewer"
	description = _("Braille viewer")
	numCells = NUM_CELLS

	@classmethod
	def check(cls):
		return True

	def __init__(self):
		super(BrailleDisplayDriver, self).__init__()
		if gui.mainFrame:
			self._frame = BrailleViewerFrame()
		else:
			# GUI not initialised yet, so we'll initialise later.
			self._frame = None

	def display(self, cells):
		if not self._frame and gui.mainFrame:
			self._frame = BrailleViewerFrame()
		if not self._frame:
			return
		self._frame.output.Label = u"".join(unichr(0x2800 + cell) for cell in cells)

	def terminate(self):
		super(BrailleDisplayDriver, self).terminate()
		try:
			self._frame.Destroy()
		except wx.PyDeadObjectError:
			# NVDA's GUI has already terminated.
			pass

Note: The braille viewer has been integrated with NVDA, find it via the tools menu.